2021/12/25 更新

写真a

カメシマ ヨシカズ
亀島 欣一
KAMESHIMA Yoshikazu
所属
環境生命科学学域 教授
職名
教授
外部リンク

学位

  • 博士(工学) ( 東京工業大学 )

研究分野

  • 環境・農学 / 環境材料、リサイクル技術

  • ナノテク・材料 / 無機材料、物性

  • ナノテク・材料 / 無機物質、無機材料化学

  • 環境・農学 / 環境負荷低減技術、保全修復技術

学歴

  • 東京工業大学   Graduate School, Division of Science and Engineering  

    - 1993年

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  • 東京工業大学   Science of Engineering  

    - 1993年

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    国名: 日本国

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  • 東京工業大学   Faculty of Engineering  

    - 1992年

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  • 東京工業大学   School of Engineering   DEAPRTMENT OF INORGANIC MATERIALS

    - 1992年

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    国名: 日本国

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所属学協会

 

論文

  • Underwater superoleophobicity of Nb2O5 photocatalyst surface 査読

    Shunsuke Nishimoto, Takahiro Takiguchi, Yoshikazu Kameshima, Michihiro Miyake

    CHEMICAL PHYSICS LETTERS   726   34 - 38   2019年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.cplett.2019.04.031

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  • Underwater wettability of oleic acid on TiO2 photocatalyst surface 査読

    Daisuke Yabumoto, Misaki Ota, Yusuke Sawai, Shunsuke Nishimoto, Yoshikazu Kameshima, Michihiro Miyake, Eiji Fujii, Ken-ichi Katsumata

    Colloids and Surfaces A: Physicochemical and Engineering Aspects   548   32 - 36   2018年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Elsevier B.V.  

    Rough and flat titanium dioxide (TiO2) surfaces were prepared, and the effect of water pH on the underwater wettability of oleic acid on the TiO2 surfaces was investigated. The underwater contact angle of oleic acid on the relatively flat TiO2 surface depended on the pH of water in the range pH 3–5. The repellency of oleic acid on the relatively flat TiO2 surface increased with decreasing pH. On the other hand, the hierarchical rough TiO2 surface repelled oleic acid in water, regardless of the pH of water.

    DOI: 10.1016/j.colsurfa.2018.03.061

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  • Electrochemical performance of Ni0.8Cu0.2/Ce0.8Gd0.2O1.9 cermet anodes with functionally graded structures for intermediate-temperature solid oxide fuel cell fueled with syngas 査読

    Michihiro Miyake, Makoto Iwami, Mizue Takeuchi, Shunsuke Nishimoto, Yoshikazu Kameshima

    Journal of Power Sources   390   181 - 185   2018年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Elsevier B.V.  

    The electrochemical performance of layered Ni0.8Cu0.2/Ce0.8Gd0.2O1.9 (GDC) cermet anodes is investigated for intermediate-temperature solid oxide fuel cells (IT-SOFCs) at 600 °C using humidified (3% H2O) model syngas with a molar ratio of H2/CO = 3/2 as the fuel. From the results obtained, the electrochemical performance of the functionally graded multi-layered anodes is found to be superior to the mono-layered anodes. The test cell with a bi-layered anode consisting of 100 mass% Ni0.8Cu0.2/0 mass% GDC (10M/0E) and 70 mass% Ni0.8Cu0.2/30 mass% GDC (7M/3E) exhibits high power density. The test cell with a tri-layered anode consisting of 10M/0E, 7M/3E, and 50 mass% Ni0.8Cu0.2/50 mass% GDC (5M/5E) exhibits an even higher power density, suggesting that 10M/0E and 5M/5E layers contribute to the current collecting part and active part, respectively.

    DOI: 10.1016/j.jpowsour.2018.04.051

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  • Preparation of carbon-modified NTiO2/ montmorillonite composite with high photocatalytic activity under visible light radiation 査読

    Jiannan Hsing, Yoshikazu Kameshima, Shunsuke Nishimoto, Michihiro Miyake

    Journal of the Ceramic Society of Japan   126 ( 4 )   230 - 235   2018年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Ceramic Society of Japan  

    In this paper, the photocatalytic activity of nitrogen-doped TiO2/montmorillonite composite (NTM) was successfully enhanced by modification with carbon. NTM was made by mixing a swelling clay solution with an N-doped TiO2 solution prepared by hydrolysis of titanium tetraisopropoxide with urea. Carbon-modified Ndoped TiO2/montmorillonite composite (CNTM) was obtained by grinding the dried NTM with EtOH for 1 h, followed by calcination at 250°C in the air for 2 h. Both NTM and CNTM exhibited visible light absorption in the UVvis spectrum in the same way as commercial NTiO2 powder. Additionally, CNTM greatly extended the absorption edges to the visible light region. The photocatalytic performance of NTM and CNTM was evaluated using a degradation of bisphenol-A under visible light (&gt
    420 nm) radiation. Although the commercial TiO2 powder showed less photocatalytic activity under visible light radiation, NTM, CNTM and commercial NTiO2 powder showed high photocatalytic activity. The order of degradation performance was as follows: CNTM &gt
    commercial NTiO2 powder &gt
    NTM. Since the TiO2 content of CNTM is ca. 30 mass% by energy dispersive spectrum analysis, it was suggested that CNTM has extremely high visible light activity.

    DOI: 10.2109/jcersj2.17235

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  • Performance of Ni0.8-xCu0.2Mx (M = Fe and Co) alloy-based cermet anodes for intermediate-temperature solid oxide fuel cells fueled with syngas 査読

    Michihiro Miyake, Sadaki Matsumoto, Shunsuke Nishimoto, Yoshikazu Kameshima

    Journal of the Ceramic Society of Japan   125 ( 11 )   833 - 836   2017年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Ceramic Society of Japan  

    The performance of Ni-based trimetallic alloy cermet anodes, Ni0.8-xCu0.2Mx (M = Fe and Co
    x = 0.1, 0.2, and 0.3)/ Ce0.8Sm0.2O1.9 (SDC), was investigated for intermediate-temperature (500700° C) solid oxide fuel cells (IT-SOFCs), using humidified (3% H2O) model syngas with a molar ratio of H2/CO = 3/2 as the fuel. Though doping Fe or Co 10 mol% into the Ni0.8Cu0.2/SDC anode led the cell performance to the increase, the cell performance decreased as Fe or Co content increased further. On the one hand, doping Fe or Co into the Ni0.8Cu0.2/SDC anode further effectively inhibited carbon deposition owing to CO on the anode. Our results suggest that the Ni0.7Cu0.2Fe0.1/SDC and Ni0.7Cu0.2Co0.1/SDC anodes are more promising materials than Ni0.8Cu0.2/SDC anode for syngas fuel in IT-SOFCs.

    DOI: 10.2109/jcersj2.17110

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  • Intermediate-temperature solid oxide fuel cell employing reformed effective biogas: Power generation and inhibition of carbon deposition 査読

    Michihiro Miyake, Makoto Iwami, Kenta Goto, Kazuhito Iwamoto, Koki Morimoto, Makoto Shiraishi, Kenji Takatori, Mizue Takeuchi, Shunsuke Nishimoto, Yoshikazu Kameshima

    JOURNAL OF POWER SOURCES   340   319 - 324   2017年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    A power generation system consisting of an intermediate-temperature solid oxide fuel cell (IT-SOFC) and an external reformer for biogas is developed, and its performance is investigated for advanced use of effective biogas. The IT-SOFC is fueled with syngas produced via biogas reforming, and is successfully operated at 600 and 700 degrees C using Ni0.8Cu0.2 alloy/gadolinia-doped ceria electrolyte (Ni0.8Cu0.2/GDC) cermet anodes and a LaAlO3 supported-Ni (Ni/LaAlO3) catalyst. The Ni/LaAlO3 catalyst stably exhibits high reforming performance for effective biogas at 800 degrees C for 27 h, and carbon deposition on the catalyst is prevented. The electrochemical performance of the Ni0.8Cu0.2/GDC cermet anode using syngas fuel possessing a H-2:CO ratio of approximately 3:1 is comparable to the performance achieved with H-2 fuel; the anode remains stable after 24 h of operation at 700 degrees C without interruption and is unaffected by carbon deposition. (C) 2016 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jpowsour.2016.11.080

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  • Electrochemical performances of Ni1-xCux/SDC cermet anodes for intermediate-temperature SOFCs using syngas fuel 査読

    Michihiro Miyake, Sadaki Matsumoto, Makoto Iwami, Shunsuke Nishimoto, Yoshikazu Kameshima

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   41 ( 31 )   13625 - 13631   2016年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    Ni-based alloy cermet anodes,Ni1-xCux (x = 0.0, 0.2, 0.5, and 1.0)/Ce0.8Sm0.2O1.9 (SDC), were prepared for use with syngas fuel in intermediate-temperature solid oxide fuel cells by in situ reduction of Ni1-xCuxO compounds. The electrochemical performances of cells with the Ni1-xCux/SDC anodes were investigated at 700 and 600 degrees C, using humidified (3% H2O) syngas with H-2/CO = 3/2 as the fuel. Cu doping of the Ni/SDC anode effectively suppressed carbon deposition on the anode. However, the cell performance was deteriorated with increasing amounts of Cu. The Ni0.8Cu0.2/SDC anode was found to be promising for use with syngas fuel. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijhydene.2016.05.070

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  • Hydrothermal Synthesis and Crystal Structure of Two New Cadmium Bismuthates, CdBi2O6 and Cd0.37Bi0.63O1.79 査読

    N. Kumada, A. Miura, T. Takei, S. Nishimoto, Y. Kameshima, M. Miyake, Y. Kuroiwa, C. Moriyoshi

    J. Asian Ceram. Soc.   3   251 - 254   2015年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.jascer.2015.04.003

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  • Biogas reforming over BaTi(1-x)Sn(x)03-supported Ni-based catalysts recovered from spent Ni-metal-hydride batteries 査読

    Miyake Michihiro, Tomiyama Natsumi, Iwamoto Kazuhito, Nagase Kentaro, Nishimoto Shunsuke, Kameshima Yoshikazu

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   40 ( 26 )   8341 - 8346   2015年7月

  • Separation of alcohol/water mixtures by ZSM-5 bulk bodies prepared with a one-pot hydrothermal method 査読

    Igi Eisaku, Kameshima Yoshikazu, Nishimoto Shunsuke, Miyake Michihiro

    MICROPOROUS AND MESOPOROUS MATERIALS   208   160 - 164   2015年5月

  • Water treatment efficacy of various metal oxide semiconductors for photocatalytic ozonation under UV and visible light irradiation 査読

    Mano Takayuki, Nishimoto Shunsuke, Kameshima Yoshikazu, Miyake Michihiro

    CHEMICAL ENGINEERING JOURNAL   264   221 - 229   2015年3月

  • Reversible Control of Underwater Oil Wettability of a Titanium Dioxide Surface through Ultraviolet and Ultrasonic Irradiation 査読

    Nishimoto Shunsuke, Mori Yuichi, Kameshima Yoshikazu, Miyake Michihiro

    CHEMISTRY LETTERS   44 ( 3 )   262 - 264   2015年3月

  • Underwater superoleophobicity of a robust rough titanium dioxide surface formed on titanium substrate by acid treatment 査読

    Nishimoto Shunsuke, Ota Misaki, Kameshima Yoshikazu, Miyake Michihiro

    COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS   464   33 - 40   2015年1月

  • 酸化物とシュウ酸を組み合わせた水中有機物の光分解 査読

    Sayaka Yanagida, Yoshikazu Kameshima, Tomohiro Isobe, Akira Nakajima, Kiyoshi Okada

    セラミックス   49 ( 6 )   469 - 472   2014年6月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • Self-cleaning efficiency of titanium dioxide surface under simultaneous UV irradiation of various intensities and water flow 査読

    Shunsuke Nishimoto, Sana Tomoishi, Yoshikazu Kameshima, Eiji Fujii, Michihiro Miyake

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   122 ( 1426 )   513 - 516   2014年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    We investigated the self-cleaning efficiencies of titanium dioxide (TiO2) surface under ultraviolet (UV) irradiation in combination with a water flow (UV/water) condition using oleic acid as the model surface contaminant. UV light intensities were varied from a typical indoor intensity level to a representative outdoor intensity level in Japan. The combined UV/water treatment exhibited a much higher self-cleaning efficiency than either condition alone. This suggests that the self-cleaning effect occurred at nanometer-sized photo-induced superhydrophilic domains of the TiO2 film surface located at the interface of the TiO2 surface, oleic acid, and air. (C) 2014 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.122.513

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  • TiO2-based superhydrophobic-superhydrophilic pattern with an extremely high wettability contrast 査読

    Shunsuke Nishimoto, Michiaki Becchaku, Yoshikazu Kameshima, Yuki Shirosaki, Satoshi Hayakawa, Akiyoshi Osaka, Michihiro Miyake

    THIN SOLID FILMS   558   221 - 226   2014年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE SA  

    Rough nanostructured anatase TiO2 surfaces containing many pores were prepared by the hydrothermal-based method. Surface modification with self-assembled monolayers (SAMs) of octadecylphosphonic acid (ODP) resulted in the superhydrophobic surface with an extremely high static water contact angle (CA) of 173.6 degrees +/- 1.7 degrees. This superhydrophobic surface could be converted into a superhydrophilic surface with a water CA of nearly 0 degrees by irradiating it with ultraviolet (UV) light, which induced photocatalytic decomposition of the ODP SAM. A superhydrophobic-superhydrophilic pattern with an extremely high wettability contrast (a water CA difference of over 170 degrees) could be fabricated on the ODP-modified TiO2 surface by area-selective UV irradiation through a photomask. This is the report of the TiO2-based superhydrophobic-superhydrophilic pattern with a water CA difference of over 170 degrees, and it may be possible to use such patterns for various applications. (C) 2014 Elsevier B. V. All rights reserved.

    DOI: 10.1016/j.tsf.2014.02.060

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  • Underwater Superoleophobicity of TiO2 Nanotube Arrays 査読

    Shunsuke Nishimoto, Yusuke Sawai, Yoshikazu Kameshima, Michihiro Miyake

    CHEMISTRY LETTERS   43 ( 4 )   518 - 520   2014年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CHEMICAL SOC JAPAN  

    TiO2 nanotube arrays prepared by the anodization of Ti plate exhibited underwater superoleophobicity. The surface almost completely repelled the oil droplet in water, even after storage in dark for one week under ambient conditions. The TiO2 nanotube arrays fabricated on a Ti mesh were found to be useful as oil-water-separation filters.

    DOI: 10.1246/cl.131155

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  • Hydrothermal preparation of tobermorite from blast furnace slag for Cs+ and Sr2+ sorption 査読

    Takuma Tsutsumi, Shunsuke Nishimoto, Yoshikazu Kameshima, Michihiro Miyake

    JOURNAL OF HAZARDOUS MATERIALS   266   174 - 181   2014年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    Al-substituted 11 angstrom-tobermorite was formed by alkaline hydrothermal treatment of blast furnace slag with sodium silicate added at 180 degrees C for 2-48 h. Effects of the hydrothermal treatment time were characterized by XRD, SEM, and isothermal adsorption of N-2. Sorption characteristics of the obtained samples were examined for Cs+ and Sr2+. The sample obtained by hydrothermal treatment for 48 h (HT-48 h) consisted of calcium silicate hydrate (C-S-H), and Al-substituted 11 angstrom-tobermorite. The HT-48 h showed the highest performance for Cs+ and Sr2+ selectivity in the presence of Na+. The interlayer Na+ of Al-substituted 11 angstrom-tobermorite and surface Ca2+ played an important role in selective Cs+ and Sr2+. (C) 2014 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jhazmat.2013.12.024

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  • Preparation and catalytic property of zirconia-system composites consist of Zr-O material derived from zirconium oxy-acid salts 査読

    Yoshikazu Kameshima, Daichi Nanba, Shunsuke Nishimoto, Michihiro Miyake

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   122 ( 1421 )   44 - 48   2014年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    Catalysts based on Zr-O material were prepared from zirconium oxychloride and zirconium oxynitrate with ultrasonication. The deposited Zr-O materials were not detected by XRD because of amorphous phase of an oxygen deficient type zirconia. The obtained zirconia based composite showed higher catalytic performance for oxygen addition activity than Pd based composite for the combustion of carbon. However, the obtained zirconia based composite showed the less catalytic performance for dehydrogenation reaction activity than Pd based composite for the combustion of methane. This zirconia based catalyst is expected to use for the electrode material of the fuel cell that needs restraint of the carbon deposition. (C)2014 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.122.44

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  • Intercalation behavior of acetyl-salicylic acid to interlayer of hydrotalcite in various organic solvents 査読

    Y. Kameshima, T. Shimizu, S. Nishimoto, M. Miyake

    Clay Science   18 ( 3 )   63 - 70   2014年

  • A5 銅ドープ酸化チタンゾル/粘土複合体による有害有機物分解挙動(口頭発表,一般講演)

    亀島 欣一, 〓 剣南, 西本 俊介, 三宅 通博

    粘土科学討論会発表論文抄録   58   38 - 39   2014年

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    記述言語:日本語   出版者・発行元:日本粘土学会  

    DOI: 10.11362/cssj2.58.0_38

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  • Hydrogen production by mechano-chemical reaction of Ti2O3 in water

    Miyuki Uno, Shunsuke Nishimoto, Yoshikazu Kameshima, Michihiro Miyake

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   38 ( 35 )   15049 - 15054   2013年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    The purpose of this study is to clarify the physicochemical properties of Ti2O3 for hydrogen production. The hydrogen production properties of Ti2O3 before and after milling in pure water were investigated in a flat-bottomed reaction vessel made of a Pyrex glass cell which was attached to a closed-gas circulation system under an Ar atmosphere at room temperature using three different types of stirring rod. Ti2O3 was found to be a new material for mechano-chemical hydrogen production, although it did not exhibit photocatalysis or mechano-catalysis for hydrogen production. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijhydene.2013.09.118

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  • Photoinduced Underwater Superoleophobicity of TiO2 Thin Films

    Yusuke Sawai, Shunsuke Nishimoto, Yoshikazu Kameshima, Eiji Fujii, Michihiro Miyake

    LANGMUIR   29 ( 23 )   6784 - 6789   2013年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    The photoinduced wettabilities of water, n-hexadecane, dodecane, and n-heptane on a flat TiO2 surface prepared by a sol gel method-based coating were investigated. An amphiphilic surface produced by UV irradiation exhibited underwater superoleophobicity with an extremely high static oil contact angle (CA) of over 160 degrees. The TiO2 surface almost completely repelled the oil droplet in water. A robust TiO2 surface with no fragile nanomicrostructure was fabricated on a Ti mesh with a pore size of approximately 150 mu m. The fabricated mesh was found to be applicable as an oil/water separation filter.

    DOI: 10.1021/la401382g

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  • The effect of UV radiation on cinnamate/layered double hydroxide (LDH) composites

    Yoshikazu Kameshima, Aya Nakada, Toshihiro Isobe, Akira Nakajima, Kiyoshi Okada

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   121 ( 1411 )   303 - 307   2013年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    Cinnamate/layered double hydroxide (LDH) composites were prepared by a reconstruction method using sodium cinnamate solution. The cinnamate solution of 100 mM was the most remarkable condition to obtain high cinnamate content of the cinnamate/LDH composite. The composite included about 30 mass % of cinnamate was prepared using the LDH with Mg/Al = 2. In this composite, the new interlayer observed in XRD at 2 theta = 4.5 degrees formed a bilayer configuration of cinnamate. This composite showed excellent UV absorbability in UV-B region. Although the interlayer cinnamate changed into a dimer structure after UV radiation, the original UV absorbability was maintained in the composite. (C)2013 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.121.303

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  • Preparation and solid acidity of zirconia-cluster/saponite composites 査読

    Yoshikazu Kameshima, Koji Kageyama, Yuuki Mizunuma, Takayuki Komatsu, Toshihiro Isobe, Akira Nakajima, Kiyoshi Okada

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   121 ( 1409 )   49 - 53   2013年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    Zirconia-cluster/saponite composites were prepared and evaluated as solid acid catalysts. The saponite layer was destructed in the composite through the dissolution of Al ion. The amount of zirconia-cluster in the composites was positively correlated with the Al amount, suggesting that zirconia-cluster inhibits the Al dissolution. Both the amounts of Bronsted and Lewis acids were increased by combining zirconia-cluster to saponite. Results show that Lewis acid on the saponite surface plays an important role on the entire catalytic activity on isomerization of 1-butene. The zirconia-cluster/saponite catalysts provided higher activity with a longer lifetime on this reaction than a commercial montmorillonite-based catalyst. (C)2013 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.121.49

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  • 畜獣骨残さから分離した水酸アパタイトによる土壌中のカドミウムの形態変化

    三瀬千暁, 片桐伴治, 西本俊介, 亀島欣一, 三宅通博

    無機マテリアル学会誌   20   96 - 100   2013年

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  • Synthesis of nickel nanoparticles with excellent thermal stability in micropores of zeolite

    Inokawa, Hitoshi, Maeda, Makoto, Nishimoto, Shunsuke, Kameshima, Yoshikazu, Miyake, Michihiro, Ichikawa, Takayuki, Kojima, Yoshitsugu, Miyaoka, Hiroki

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   38 ( 31 )   13579 - 13586   2013年

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    掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.ijhydene.2013.08.027

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  • B18 塩化金属塩/層状複水酸化物を利用したエタノール改質触媒(口頭発表,一般講演)

    亀島 欣一, 小橋 壮亮, 西本 俊介, 三宅 通博

    粘土科学討論会発表論文抄録   57   114 - 115   2013年

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    記述言語:日本語   出版者・発行元:日本粘土学会  

    DOI: 10.11362/cssj2.57.0_114

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  • Fabrication of Large Porous ZSM-5 Bulk Bodies by a One-pot Hydrothermal Method

    Eisaku Igi, Yoshikazu Kameshima, Shunsuke Nishimoto, Michihiro Miyake

    CHEMISTRY LETTERS   41 ( 11 )   1414 - 1416   2012年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CHEMICAL SOC JAPAN  

    The fabrication of large ZSM-5 bulk bodies by a hydrothermal method was investigated. The results reveal that porous ZSM-5 bulk bodies with sizes of the order of centimeters could be prepared by the one-pot hydrothermal method using raw materials for synthesizing ZSM-5 powder. Machinability tests and mechanical strength measurements suggest that the bulk bodies obtained are promising as practical materials.

    DOI: 10.1246/cl.2012.1414

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  • Electrode properties of doped Pr2NiO4-based oxide cathode for intermediate-temperature SOFCs

    Takeshi Nomura, Shunsuke Nishimoto, Yoshikazu Kameshima, Michihiro Miyake

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   120 ( 1407 )   534 - 538   2012年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    K2NiF4-type Pr2NiO4 doped with Cu, Cu-Ga, or Co (Pr2Ni0.9Cu0.1O4, Pr2Ni0.75Cu0.25O4, Pr1.91Ni0.71Cu0.24Ga0.05O4, or Pr2Ni0.9Co0.1O4) were synthesized by a solid-state reaction for use as cathodes in an intermediate-temperature (500-700 degrees C) solid oxide fuel cell (IT-SOFC). Pr2NiO4, Pr2Ni0.9Cu0.1O4, Pr2Ni0.75Cu0.25O4, Pr1.91Ni0.71Cu0.24Ga0.05O4 and Pr2Ni0.9Cu0.1O4 crystallize in the space group Bmab. Single test cells with samarium oxide doped ceria (SDC) as the electrolyte, Ni-SDC cermet as the anode, and the above-mentioned cathode material were fabricated for cell performance measurements at 700 degrees C. Current interruption measurements and electrochemical impedance spectroscopic analysis revealed that the cathode properties of Pr2NiO4, Pr2Ni0.9Cu0.1O4, Pr2Ni0.75Cu0.25O4, and Pr1.91Ni0.71Cu0.24Ga0.05O4 were comparable to that of La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) and the cathode properties of Pr2NiO4 were improved by doping with Cu or Cu-Ga at the Ni site of Pr2NiO4. (C)2012 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.120.534

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  • Determination of carbonate ion contents in layered double hydroxides by FTIR spectrometry

    Toshiyuki Tanaka, Yoshikazu Kameshima, Shunsuke Nishimoto, Michihiro Miyake

    ANALYTICAL METHODS   4 ( 12 )   3925 - 3927   2012年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ROYAL SOC CHEMISTRY  

    A novel method for determining the carbonate ion contents in layered double hydroxides (LDHs) was demonstrated by FTIR spectrometry. Deconvolution using a curve-fitting technique was performed on the FTIR spectra of LDHs containing both carbonate and carboxylate ions in the interlayer. The contents of carbonate ion calculated from the FTIR spectra were in accordance with those obtained from the chemical composition analysis.

    DOI: 10.1039/c2ay25850a

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  • Porous ceramics mimicking nature-preparation and properties of microstructures with unidirectionally oriented pores

    Kiyoshi Okada, Toshihiro Isobe, Ken-ichi Katsumata, Yoshikazu Kameshima, Akira Nakajima, Kenneth J. D. MacKenzie

    SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS   12 ( 6 )   2011年12月

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    記述言語:英語   出版者・発行元:NATL INST MATERIALS SCIENCE  

    Porous ceramics with unidirectionally oriented pores have been prepared by various methods such as anodic oxidation, templating using wood, unidirectional solidification, extrusion, etc. The templating method directly replicates the porous microstructure of wood to prepare porous ceramics, whereas the extrusion method mimics the microstructures of tracheids and xylems in trees. These two methods are therefore the main focus of this review as they provide good examples of the preparation of functional porous ceramics with properties replicating nature. The well-oriented cylindrical through-hole pores prepared by the extrusion method using fibers as the pore formers provide excellent permeability together with high mechanical strength. Examples of applications of these porous ceramics are given, including their excellent capillary lift of over 1m height which could be used to counteract urban heat island phenomena, and other interesting properties arising from anisotropic unidirectional porous structures.

    DOI: 10.1088/1468-6996/12/6/064701

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  • Investigation of photocatalytic ozonation treatment of water over WO3 under visible light irradiation

    Takayuki Mano, Shunsuke Nishimoto, Yoshikazu Kameshima, Michihiro Miyake

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   119 ( 1395 )   822 - 827   2011年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    The aim of this study is to develop a highly efficient and environmentally friendly water treatment technique. Water treatment by photocatalytic zonation over bare WO3 under visible light irradiation (O-3/vis/WO3) system was performed under different experimental conditions using a phenol aqueous solution as model wastewater. The effects of parameters such as the initial phenol concentration, water temperature, and initial solution pH on the total organic carbon (TOC) removal efficiency in the O-3/vis/WO3 system were investigated. The results suggest that the TOC removal process consists of three stages, and the combined effect of photocatalysis and ozonation, which is important for complete TOC removal, became dominant in the third stage. Furthermore, the TOC removal efficiency increased with increasing water temperature in the O-3/vis/WO3 system. (C) 2011 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.119.822

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  • Promotion of H-2 production from ethanol steam reforming by zeolite basicity

    Hitoshi Inokawa, Shunsuke Nishimoto, Yoshikazu Kameshima, Michihiro Miyake

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   36 ( 23 )   15195 - 15202   2011年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    The effect of the basicity of zeolite as a metallic catalyst substrate on ethanol steam reforming reaction was investigated. Catalysts with various basicities were prepared using an ion exchange process with aqueous solutions including Na+, K+ and Cs+ after an impregnation process of Ni on Na-Y zeolite (referred to as Ni/Na-Y, Ni/K-Y and Ni/Cs-Y, respectively). Infrared spectroscopy indicated that the OH bonds of ethanol molecules adsorbed on zeolites were weakened with increasing zeolite basicity. H-2 production at 300 degrees C increased in the order of Ni/Cs-Y > Ni/K-Y > Ni/Na-Y, and selectivity for a high production ratio of H-2 to C2H4 was significantly promoted by exchanging Na+ for K+ or Cs+. H-2 production at 500 degrees C was also enhanced by the zeolite basicity; however, degradation of catalytic activity was mainly caused by carbon deposition on the three samples at this temperature. Ni/Cs-Y, with higher H-2 production than Ni/Na-Y, also exhibited higher resistance to carbon deposition. Increase of the zeolite basicity was effective for selective acceleration of the dehydrogenation reaction with ethanol, inhibition of coke deposition, and the promotion of H-2 production. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijhydene.2011.08.099

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  • Fabrication of layered double hydroxide/photoresponsive dendron nanocomposite multilayer film by electrostatic layer-by-layer assembly

    Toshiyuki Tanaka, Shunsuke Nishimoto, Yoshikazu Kameshima, Michihiro Miyake

    MATERIALS LETTERS   65 ( 15-16 )   2315 - 2318   2011年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    A novel inorganic-organic nanoscopic multilayer film consisting of exfoliated MgAl-type layered double hydroxide (LDH) nanosheets and anthryl dendrons [i.e., poly(amidoamine) dendrons with an anthracene chromophore group at the focal point] was fabricated using an electrostatic layer-by-layer (LbL) assembly. UV-vis spectroscopy and X-ray diffraction analysis indicated the successful LbL growth of dendron/LDH multilayer films. Furthermore, fluorescence spectroscopic analysis indicated that the dendrons are present as a monolayer between LDH nanosheets in the film. (C) 2011 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.matlet.2011.05.004

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  • Photocatalytic activities of various pentavalent bismuthates under visible light irradiation

    Takahiro Takei, Rie Haramoto, Qiang Dong, Nobuhiro Kumada, Yoshinori Yonesaki, Nobukazu Kinomura, Takayuki Mano, Shunsuke Nishimoto, Yoshikazu Kameshima, Michihiro Miyake

    JOURNAL OF SOLID STATE CHEMISTRY   184 ( 8 )   2017 - 2022   2011年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    LiBiO(3), NaBiO(3), MgBi(2)O(6), KBiO(3), ZnBi(2)O(6), SrBi(2)O(6), AgBiO(3), BaBi(2)O(6) and PbBi(2)O(6) were synthesized by various processes such as hydrothermal treatment, heating and so on. These materials were examined for their photocatalytic activities in the decolorization of methylene blue and decomposition of phenol under visible light irradiation. For methylene blue decolorization, the presence of KBiO(3) resulted in complete decoloration within 5 min. For phenol decomposition, NaBiO(3) showed the highest activity, while LiBiO(3), SrBi(2)O(6) and BaBi(2)O(6) possessed almost comparable decomposition rates. Their decomposition rates were apparently higher than that by anatase (P25) under UV irradiation. (C) 2011 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.jssc.2011.06.004

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  • Preparation and crystal structure of a new bismuth vanadate, Bi-3.33(VO4)(2)O-2

    N. Kumada, T. Takei, R. Haramoto, Y. Yonesaki, Q. Dong, N. Kinomura, S. Nishimoto, Y. Kameshima, M. Miyake

    MATERIALS RESEARCH BULLETIN   46 ( 6 )   962 - 965   2011年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    Single crystals of a new bismuth vanadate, Bi-3.33(VO4)(2)O-2 was prepared by hydrothermal reaction using a hydrated sodium bismuthate, NaBiO3 center dot nH(2)O as one of the starting compounds. The crystal structure was determined by using single crystal X-ray diffraction data. This compound crystallizes in the triclinic space group P (1) over bar (#2) with a = 7.114(1), b = 7.844(2), c = 9.372(2) angstrom, alpha = 106.090(7), beta = 94.468(7) and gamma = 112.506(8)degrees, Z = 2 and the final R factors are R1 = 0.052 and wR2 = 0.14 for 2085 unique reflections. The crystal structure is composed by four bismuth atoms with the coordination number of 6 or 8 and two VO4 tetrahedra, and one of four bismuth atoms is statistically distributed in the splitting sites with the distance of 0.83 angstrom. This compound exhibited photocatalytic behavior for decomposition of phenol under visible light irradiation and its activity was less than that of monoclinic BiVO4. (C) 2011 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.materresbull.2011.02.009

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  • Adsorption and photocatalytic properties of TiO2/mesoporous silica composites from two silica sources (acid-leached kaolinite and Si-alkoxide)

    K. Okada, A. Yoshizawa, Y. Kameshima, T. Isobe, A. Nakajima, K. J. D. Mackenzie

    JOURNAL OF POROUS MATERIALS   18 ( 3 )   345 - 354   2011年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    Two different mesoporous silicas (MPS) were synthesized by hydrothermal treatment in NaOH solution of two SiO2 sources. These were microporous silica (MicroPS) derived from selectively acid leached metakaolinite and tetraethylorthosilicate (TEOS). The hydrothermal syntheses of the MPSs were performed at a ratio of SiO2/cetyltrimethyl- ammonium bromide (CTABr)/NaOH/H2O = 1/0.1/0.3/150. The specific surface areas (S (BET)) of the MPSs from MicroPS (MPS(M)) and TEOS (MPS(T)) were 1070 and 1020 m(2)/g, respectively. Composites of MPS (75 mass%) with TiO2 (25 mass%) were prepared using both SiO2 and two commercial TiO2 powders, P25 and ST-01. The adsorption-desorption behavior of methylene blue (MB) by the four resulting composites and the two MPSs alone was unique in showing partially reversible behavior. The maximum MB adsorption, observed in the composite of ST-01 with MPS(M), designated (S/M), was 0.034 mmol/g. The rates of MB adsorption in the dark and photodecomposition under UV illumination were considerably different for the four composites and two TiO2 powers, and followed the order ST-01 < S/T < P25 < P/T a parts per thousand P/M a parts per thousand(a) S/M. The removal rate of MB by the composite S/M by adsorption and photodecomposition was further enhanced by heating at 700 A degrees C. Direct photodecomposition of MB without adsorption in the dark was greatly enhanced in the composites, especially in that composed of MPS(M) and ST-01.

    DOI: 10.1007/s10934-010-9384-2

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  • Temperature dependence of hydrogen adsorption properties of nickel-doped mesoporous silica

    Yoshifumi Yamamoto, Nozomi Nawa, Shunsuke Nishimoto, Yoshikazu Kameshima, Motohide Matsuda, Michihiro Miyake

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   36 ( 9 )   5739 - 5743   2011年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    The temperature dependence of the hydrogen adsorption properties of nickel-doped mesoporous silica (MCM-41) synthesized by a direct hydrothermal method was investigated by measuring the amount of hydrogen adsorbed at pressures up to 100 kPa at 298, 373, and 473 K. Nickel-doped MCM-41 adsorbed more hydrogen than undoped MCM-41 and metallic nickel at approximate to 298/0, 373/0, and 473 K/0 kPa due to chemical adsorption enhanced by the highly dispersed nickel particles. Chemical adsorption increased with increasing nickel content and adsorption temperature, suggesting the presence of adsorption sites. The nickel doping also brought the spillover effect, which enhances the physical adsorption of hydrogen. The spillover effect was enhanced at high nickel contents and adsorption temperatures. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijhydene.2011.02.010

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  • Properties of La2-xPrxNiO4 cathode for intermediate-temperature solid oxide fuel cells

    Shunsuke Nishimoto, Sugurn Takahashi, Yoshikazu Kameshima, Motohide Matsuda, Michihiro Miyake

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   119 ( 1387 )   246 - 250   2011年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    A series of K2NiF4-type compounds, La2-xPrxNiO4 (x = 0, 0.6, 1.0, 1.4, and 2.0), were synthesized by solid state reaction for use as cathodes in an intermediate-temperature (500-700 degrees C) solid oxide fuel cell (IT-SOFC). La(2-x)Pr(x)Nia(4) (x = 0 and 0.6) crystallize in the Fmmm space group, while La2-xPrxNiO4 (x = 1.0, 1.4, and 2.0) belong to the Bmab space group. The electrical conductivity increased by Pr doping and La2-xPrxNiO4 (x = 0.6, 1.0, and 1.4) exhibited electrical conductivities similar to one another while Pr2NiO4 had the highest. Single test-cells consisting of samarium oxide doped ceria (SDC) as an electrolyte, Ni-SDC cermet as an anode and La2-xPrxNiO4 as a cathode, were fabricated for measurements of cell performance at 500-700 degrees C. Current interruption measurements revealed that the overpotential losses mainly decreased with increasing Pr content. Pr2NiO4 was found to exhibit the best cathode characteristics; maximum lest-cell power densities of 14.1, 45.1, and 104.4 mW/cm(2) were obtained at 500, 600, and 700 degrees C, respectively. (C) 2011 The Ceramic Society of Japan. All rights reserved.

    DOI: 10.2109/jcersj2.119.246

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  • Ni2+ and H2PO4- uptake properties of compounds in the CaTiO3-CaFeO2.5 system

    Catalin Popa, Yoshikazu Kameshima, Toshihiro Isobe, Akira Nakajima, Kiyoshi Okada

    JOURNAL OF HAZARDOUS MATERIALS   185 ( 2-3 )   1390 - 1397   2011年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    A batch method was used to investigate the uptake of heavy metal cations and anions by the compounds in the CaTiO3-CaFeO2.5 system, in which a series of oxygen vacancies was systematically introduced into a perovskite structure as the x-value of Ca(FexTi1-x)O3-x/2 was increased. Samples of CaTiO3, CaFe0.1Ti0.9O2.95, CaFe0.5Ti0.5O2.75, CaFe0.67Ti0.33O2.67 and CaFeO2.5 were prepared by solid mixing (SM), co-precipitation (CP) and gel evaporation (GE) methods. The resulting samples were calcined at temperatures between 400 and 1000 degrees C. The target crystalline phases differed according to the preparation method, but in most cases were formed at 700-800 degrees C. The Ni2+ sorption isotherms of all the samples were fitted better by the Langmuir model than by the Freundlich model, while in the case of H-2 PO4- sorption isotherms, these were better fitted by the latter model. The uptake ability increased with increasing x value of the samples. The maximum values for the saturated sorption of Ni2+ (Q(0)(Ni2+)= 2.83 mmol/g) and H-2 PO4- (K-F(H2PO4-)= 2.95 mmol/g) were achieved for x = 1 (i.e. CaFeO2.5) sample. (C) 2010 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jhazmat.2010.10.060

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  • Preparation and Delamination Behavior of Lactate/Layered Double Hydroxide (LDH) Composites Using Reconstruction Method

    K. Okudaira, Y. Kameshima, T. Isobe, A. Nakajima, K. Okada

    J. Jpn. Soc. Colour Mater.   84 ( 1 )   2 - 6   2011年

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  • Photocatalytic water treatment over WO3 under visible light irradiation combined with ozonation 査読

    Nishimoto Shunsuke, Mano Takayuki, Kameshima Yoshikazu, Miyake Michihiro

    CHEMICAL PHYSICS LETTERS   500 ( 1-3 )   86 - 89   2010年11月

  • Difference in the catalytic activity of transition metals and their cations loaded in zeolite Y for ethanol steam reforming 査読

    Inokawa Hitoshi, Nishimoto Shunsuke, Kameshima Yoshikazu, Miyake Michihiro

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   35 ( 21 )   11719 - 11724   2010年11月

  • Characterization of Silicon Oxide Nanowires Prepared by Hydrothermal Treatment Using Slow Dissolution of Bulk Glass Source Materials 査読

    Kita Tomoyuki, Nishimoto Shunsuke, Kameshima Yoshikazu, Miyake Michihiro

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY   93 ( 9 )   2427 - 2429   2010年9月

  • Preparation and photocatalytic activity of [PWxMo12-xO40]3-/TiO2 hybrid film composites 査読

    Akira Nakajima, Tomohisa Koike, Sayaka Yanagida, Toshihiro Isobe, Yoshikazu Kameshima, Kiyoshi Okada

    Applied Catalysis A-GENERAL   385   130 - 135   2010年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.apcata.2010.07.001

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  • Oleate-LDH Hybrids by the Successive Use of the Clay Structural "Memory Effect" 査読

    Gabriela Carja, Yoshikazu Kameshima, Gabriela Ciobanu, Kiyoshi Okada

    JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY   10 ( 4 )   2880 - 2884   2010年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER SCIENTIFIC PUBLISHERS  

    Oleate/LDH composites have been obtain by calcination-reconstruction procedures by the successive uses of the anionic clay memory effect. XRD and FTIR analysis were used to study the structural characteristics of the hybrid samples. The amount of oleate in the hybrid formulation of the clay matrix is highest after the second calcination-reconstruction cycle. After the fourth cycle the clay structure is not recovered anymore. This result points out to the "short" structural "memory" of the LDH-like clays. Textural features of the samples were studied by N(2) adsorption at 77 K, SEM and TEM analyses. The oleate/LDH hybrids, obtained by the successive uses of the clay "memory," are defined by different crystallinity and micromorphological characteristics.

    DOI: 10.1166/jnn.2010.1389

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  • Preparation of heteropolyacid-intercalated layered double hydroxide 査読

    Sayaka Yanagida, Akira Nakajima, Yoshikazu Kameshima, Kiyoshi Okada

    Jounal of Ion Exchange   18 ( 4 )   270 - 275   2010年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • Porous properties of mesoporous silicas from two silica sources (acid-leached kaolinite and Si-alkoxide) 査読

    K. Okada, H. Yoshizaki, Y. Kameshima, A. Nakajima, K. J. D. Mackenzie

    JOURNAL OF POROUS MATERIALS   17 ( 1 )   19 - 25   2010年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    Two different mesoporous silicas (MesoPS) were synthesized by hydrothermal treatment in NaOH solution of two silica sources. One of these starting silicas was derived from selectively acid leached metakaolinite, and the other was from tetraethylorthosilicate (TEOS). The syntheses used a surfactant, cethyltrimethylammonium bromide (CTABr) and were carried out at different CTABr/Si, NaOH/Si and H(2)O/Si ratios. In the MesoPS from kaolinite, the specific surface areas (S (BET)) of the products were > 1500 m(2)/g when prepared with 0.2 a parts per thousand currency sign CTABr/Si a parts per thousand currency sign 0.4, 0.3 a parts per thousand currency sign NaOH/Si a parts per thousand currency sign 0.6 and H(2)O/Si = 150. These S (BET) values are higher than those obtained from TEOS (ca. 1300 m(2)/g). The XRD patterns of these products contain a hexagonal (10-) peak with a lattice parameter a (0) = 4.2-5.2 nm in the MesoPS derived from kaolinite and a (0) = 4.0-4.6 nm in the products from TEOS. The regularity of the hexagonal structure is higher in the MesoPS derived from TEOS than from kaolinite. The pore size distributions of the products show a sharp peak at 2.8 nm in the MesoPS from kaolinite and at 2.4-2.5 nm in those from TEOS. The meso-structure is found to be formed during the stirring step of the synthesis and becomes more regular after hydrothermal treatment. The differences in the porous properties of the two MesoPSs from kaolinite and TEOS are attributed to differences in the dissolution rates and silica concentrations in the synthesis solutions. The (29)Si MAS NMR spectra show a higher number of Q (3) (Si(OSi)(3)OH) units in the MesoPS from kaolinite and this is suggested to be related to the difference in their porous properties.

    DOI: 10.1007/s10934-008-9260-5

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  • Various factors affecting photodecomposition of methylene blue by iron-oxides in an oxalate solution 査読

    Fahmida Gulshan, Sayaka Yanagida, Yoshikazu Kameshima, Toshihiro Isobe, Akira Nakajima, Kiyoshi Okada

    Water Research   44   2876 - 2884   2010年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • AFM Interaction Study of Poly(ammomum acrylate) Adsorbed on a Si Surface in Aqueous KCl Solution 査読

    Isobe Toshihiro, Nakano Yosuke, Kameshima Yoshikazu, Okada Kiyoshi, Nakajima Akira

    Chemistry Letters   39 ( 12 )   1275 - 1276   2010年

  • Water vapor adsorption of CaCl2-impregnated activated carbon 査読

    Okada Kiyoshi, Nakanome Mad, Kameshima Yoshikazu, Isobe Toshihiro, Nakajima Akira

    Materials Research Bulletin   45 ( 11 )   1549 - 1553   2010年

  • A novel nanocomposite material prepared by intercalating photoresponsive dendrimers into a layered double hydroxide 査読

    Tanaka Toshiyuki, Nishimoto Shunsuke, Kameshima Yoshikazu, Matsukawa Junpei, Fujita Yasuhiko, Takaguchi Yutaka, Matsuda Motohide, Miyake Michihiro

    Journal of Solid State Chemistry   183 ( 2 )   479 - 484   2010年

  • Dynamic hydrophobicity of water droplets on the line-patterned hydrophobic surfaces

    J. -H. Song, M. Sakai, N. Yoshida, S. Suzuki, Y. Kameshima, A. Nakajima

    SURFACE SCIENCE   600 ( 13 )   2711 - 2717   2006年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    Static and dynamic hydrophobicities of water droplet on a patterned surface prepared using fluoroalkylsilanes with different molecular chain lengths were investigated. Contact angles on the patterned surfaces well agreed with values predicted using Cassie's theory. On the same line width ratio, total retention force was governed by the fluoroalkylsilane with slow-sliding acceleration. The total retention force decreased with the decreasing width ratio of silane with slow-sliding acceleration on the surface. These results imply that the sliding acceleration of water droplets on a hydrophobic surface depends both on chemical composition and patterning structure. (c) 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.susc.2006.04.044

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  • Preparation and properties of titania-apatite hybrid films

    A Nakajima, K Takakuwa, Y Kameshima, M Hagiwara, S Sato, Y Yamamoto, N Yoshida, T Watanabe, K Okada

    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY   177 ( 1 )   94 - 99   2006年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE SA  

    TiO2-hydroxyapatite (HAp) hybrid films were prepared by laminating TiO2 films with holes on the HAp film. We prepared transparent porous HAp film through spray pyrolysis deposition (SPD) method. The HAp possessed affinity against proteins. TiO2 films were prepared using phase separation of alkoxide. The holes provided from this process serve as an adsorption field and photocatalytic reaction field for reactants. This work demonstrated that the TiO2-HAp hybrid films produced by this process are candidates for photocatalytic decomposition of germs, viruses, and other biohazardous substances in the environment. (c) 2005 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jphotochem.2005.05.019

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  • A9 超音波照射による水中での1,4-ジオキサン分解におけるTiO_2粉末の添加効果

    佐々木 洋和, 中島 章, 亀島 欣一, 岡田 清

    ソノケミストリー討論会講演論文集   15   19 - 20   2006年

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    記述言語:日本語   出版者・発行元:日本ソノケミストリー学会  

    Effects of TiO_2 powder addition on sonochemical destruction of 1,4-dioxane in water were investigated through comparison of SiO_2 powders with similar specific surface area. Addition of TiO_2 is more effective for decomposition of 1,4-dioxane in water than is SiO_2. Contribution of photocatalytic destruction through sonoluminescence is not a dominant mechanism to for the acceleration of sonochemical reactions by adding TiO_2. Regarding sonication of TiO_2-added water in the current case, thermally excited holes will be generated. Intrinsic oxygen vacancies in TiO_2 surface will also play an important role for high decomposition efficiency by producing cavitations. Both ultrasonication energy consumed in water and destruction efficiency of 1,4-dioxane were increased by the addition of reduced TiO_2 powder.

    DOI: 10.20577/pamjss.15.0_19

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  • Preparation of ZSM-5 zeolite honeycomb monoliths using microporous silica obtained from metakaolinite 査読

    CD Madhusoodana, RN Das, Y Kameshima, K Okada

    JOURNAL OF POROUS MATERIALS   12 ( 4 )   273 - 280   2005年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    Zeolite honeycomb monoliths were prepared from ZSM-5 powders synthesized under hydrothermal conditions using microporous silica obtained by selective leaching of metakaolinite. This honeycomb material was compared with those prepared using alkoxides (TEOS) as the silica source. The honeycomb monoliths were formed by extrusion of paste made from the synthesized powders through a multi-channel honeycomb die. The morphology and porous properties of these materials were studied using XRD, FTIR, SEM and N-2/Ar adsorption. ZSM-5 grains in the monoliths prepared from metakaolinite showed platy morphology with preferred orientation of the crystals in the extruded surface, and displayed an absence of secondary growth. The twinned morphology of ZSM-5 crystals was observed in the monoliths prepared using TEOS and this contributed to an increase in the external surface area even though the total surface area was identical to that of samples prepared from metakaolinite. The physical properties, thermal stability and mechanical strength of the monoliths was compared with zeolite-coated honeycombs. The results show that microporous silica prepared by acid leaching of metakaolinite is a cost-effective raw material for preparing ZSM-5 honeycomb monoliths with controlled morphology and tunable SiO2/Al2O3 ratios.

    DOI: 10.1007/s10934-005-3125-y

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  • Preparation of a crack-free rough titania coating on stainless steel mesh by electrophoretic deposition 査読

    Sayaka Yanagida, Akira Nakajima, Yoshikazu Kameshima, Kiyoshi Okada

    Materials Research Bulletin   40   1135 - 1344   2005年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • Effect of vacuum ultraviolet light illumination on the crystallization of sol-gel-derived titanium dioxide precursor films 査読

    A Nakajima, N Hayashi, Y Taniguchi, Y Kameshima, K Okada

    SURFACE & COATINGS TECHNOLOGY   192 ( 1 )   112 - 116   2005年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE SA  

    Crystallization behavior of sol-gel-based TiO2 precursor films by vacuum ultraviolet (VUV) light illumination was investigated. VUV light illumination induces densification of films. This reaction accompanies the removal of organic compounds and OH groups with increasing apparent coordination number of titanium in the film from five to six. This structure change enhances film crystallization; polycrystalline anatase films were obtained by post annealing at 300 degreesC. Crystallization behavior suggested that proper balance of densification and removal of organic compounds are important tasks for further lowering crystallization temperature. (C) 2004 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.surfcoat.2004.04.034

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  • Comparative study of apatite formation on CaSiO3 ceramics in simulated body fluids with different carbonate concentrations 査読

    Y Iimori, Y Kameshima, K Okada, S Hayashi

    JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE   16 ( 1 )   73 - 79   2005年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    Apatite formation on CaSiO3 ceramics was investigated using two different simulated body fluids (SBF) proposed by Kokubo (1990) and Tas (2000) and three sample/SBF (S/S) ratios (1.0, 2.5 and 8.3 mg/ml) at 36.5 degreesC for 1-25 days. The CaSiO3 ceramic was prepared by firing coprecipitated gel with Ca/Si = 0.91 at 1400degreesC. The bulk density was 2.14 g/cm(3) and the relative density about 76%. The two SBF solutions contain different concentrations of HCO3- and Cl- ions, the concentrations of which are closer to human blood plasma in the Tas SBF formulation than in the Kokubo formulation. The pH values in the former solution are also more realistic. The CaSiO3 ceramics show apatite formation in SBF (Kokubo) after soaking for only 1 day at all S/S ratios whereas different phases were formed at each S/S ratio in SBF (Tas). The crystalline phases formed were mainly apatite at S/S = 1.0 mg/ml, carbonate-type apatite at 2.5 mg/ml and calcite at 8.3 mg/ml. At higher S/S ratios the increase in the Ca concentration became higher while the P concentration became lower in the reacted SBF. These changes in SBF concentrations and increasing pH occurred at higher S/S ratios, producing more favorable conditions in the SBF for the formation of carbonate bearing phases, finally leading to the formation of calcite instead of apatite in the higher HCO3- ion concentration SBF (Tas). Apatite is, however, formed in the lower HCO3- ion concentration SBF (Kokubo) even though the Ca and P concentrations change in a similar manner to SBF (Tas). (C) 2005 Springer Science + Business Media, Inc.

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  • Low temperature synthesis of AlN by addition of various Li-salts 査読

    Y Kameshima, M Irie, A Yasumori, K Okada

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   24 ( 15-16 )   3801 - 3806   2004年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    The effect of various Li-salts on the low temperature synthesis of AlN by direct nitridation of Al metal was investigated using four Al powders with average particle sizes of 3, 20, 100 and 150 mum. These were mixed with various Li-salts (LiNO3, LiOH.H2O and Li2CO3) in different concentrations and fired at various temperatures under flowing N-2. The as-received Al powders without Li addition showed AIN formation at about 600degreesC in the 3 and 20 mum samples but no AIN formation up to 850degreesC in the 100 and 150 mum samples. The crystallinity of the AIN products, where formed, was however low. By contrast, all the Al powders with added Li-salts showed AIN formation up to 800degreesC, with LiOH.H2O being especially effective. Thus, the AIN formation temperature can be significantly lowered in the coarser powders by the addition of Li-salts but the effect is less in the finer powders which undergo low temperature nitridation below the melting point of Al metal even without Li. The crystallinity of the AIN products was higher in the samples containing Li-salts than without Li-salts. (C) 2004 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.jeurceramsoc.2003.12.028

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  • Ni(2+) uptake by amorphous and crystalline Ca(2)Al(2)SiO(7) synthesized by solid-state reaction of kaolinite 査読

    VK Jha, Y Kameshima, K Okada, KJD Mackenzie

    SEPARATION AND PURIFICATION TECHNOLOGY   40 ( 2 )   209 - 215   2004年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    The uptake of Ni(2+) by amorphous and crystalline gehlenite (Ca(2)Al(2)SiO(7)) was investigated. The Ca(2)Al(2)SiO(7) samples were prepared by solid-state reaction of mixtures of kaolinite, calcite, and aluminum hydroxide mechanochemically treated the mixture for 0-24h and fired at 600-900degreesC for 24 h. The mechanochemically treated samples crystallized to form gehlenite at greater than or equal to850degreesC, below which temperature they were amorphous. Ni(2+) uptake experiments were performed by a batch method at 25 degreesC using a solid/solution ratio of 0.002 g ml(-1) and a Ni(2+) concentration of 10(-4); to 5 x 10(-2) M. The uptake capability increased with increasing pH > 6 and decreasing initial Ni(2+) concentration. The amorphous sample showed a higher Ni(2+) uptake than the crystalline sample, and its uptake was also higher than values reported in the literature for amorphous CaAl(2)Si(2)O(8), zeolites, gylorite, and activated carbon. (C) 2004 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.seppur.2004.02.010

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  • Effect of Solid/Solution Ratio on Apatite Formation from CaSiO3 Ceramics in Simulated Body Fluid 査読

    Yusuke Iimori, Yoshikazu Kameshima, Atsuo Yasumori, Kiyoshi Okada

    J. MATERIALS SCIENCE-MATERIALS IN MEDICINE   15 ( 11 )   1247 - 1253   2004年11月

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  • Crystallization Behavior of CaO-Al2O3-SiO2 Glass-Ceramics Prepared from Wastes of Glass and Clay Raw Materials(Kira) 査読

    Tomohiko Toya, Yoshikazu Kameshima, Atsuo Yasumori, Kiyoshi Okada

    KEY ENGINEERING MATERIALS   264-268   1843 - 1846   2004年8月

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  • Comparative Study of Apatite Formation on CaSiO3 Ceramics Prepared by Glass Crystallizatio and Sintering Methods in Simulate Body Fluid 査読

    Yusuke Iimori, Yoshikazu Kameshima, Atsuo Yasumori, Kiyoshi Okada

    KEY ENGINEERING MATERIALS   264-268   1965 - 1968   2004年8月

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  • Mechanochemical effect on low temperature synthesis of AlN by direct nitridation method 査読

    Y Kameshima, M Irie, A Yasumori, K Okada

    SOLID STATE IONICS   172 ( 1-4 )   185 - 190   2004年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    Effect of mechanochemical treatment on low temperature synthesis of AlN from Al metal in N-2 atmosphere was investigated. The Al powder, of 20-mum particle size, was dry milled using a planetary ball mill. Since Al powder is soft and malleable, the particle size tended to increase due to adhesion of the original particles during grinding. On the other hand, effective grinding was achieved by adding LiOH H2O, which is thought to cover the surfaces of Al powder and suppress the adhesion. Samples containing 0.5 mass% Li in Li/(Li + Al) were ground for various times up to 6 h, then nitrided for 1 h at various temperatures. AlN formation in these samples began at 570-640degreesC, much lower than without (LiOHH2O)-H-., indicating the accelerating effect of the added (LiOHH2O)-H-.. The conversion temperature was lowest in the sample ground for I h. This sample (mechano-sample) also showed a higher AlN conversion rate than the other samples, being almost completely converted at 580degreesC. The mechanochemical treatment is found to be very effective for synthesizing AlN powder at very low temperatures (below the melting point of Al metal). It is thought to facilitate the formation of lithium aluminate on the surface of the Al metal particles, enhancing the diffusion of nitrogen. (C) 2004 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.ssi.2004.05.015

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  • Preparation of zeolite-coated cordierite honeycombs prepared by an in situ crystallization method 査読

    K Okada, Y Kameshima, CD Madhusoodana, RN Das

    SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS   5 ( 4 )   479 - 484   2004年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:NATL INST MATERIALS SCIENCE  

    Zeolite thin films were prepared on cordierite (Mg2Al4Si5O18) honeycomb substrates by in situ crystallization using soft hydrothermal conditions. The synthesized zeolite films (zeolite A and ZSM-5) were characterized by XRD, FTIR, SEM, NH3-TPD, and Ns(2) and propane gas adsorption. Zeolite-A films were prepared by dip-coating on a cordierite substrate in a precursor of molar composition of Na2O:Al2O3:SiO2:H2O = 4:1:2:100 and heating in an autoclave at 80 degreesC for 6-10 h. The resultant zeolite-A films consisted of cubic crystals about 2-3 mum in size, achieving a thickness of 20 mum after re-coating. ZSM-5 films were similarly formed using a microporous silica precursor obtained by selective leaching of metakaolinite with tetrapropylammonium hydroxide (TPAOH) as the templating agent. The molar composition of the precursor was NaOH:microporous silica:TPAOH:H2O = 1:10:1:200. The dipped substrate covered with the wet precursor gel was heated in an autoclave at 150 degreesC for 24 h. The resultant films were composed of short prismatic <1 mum crystals achieving thickness of several to 10 mum after re-coating. The microstructure and porous properties of the ZSM-5 films were found to change according to the chemical composition and surface treatment of the cordierite substrates. The presence of a SiO2-rich interfacial layer between the substrate and zeolite film increased the amount of zeolite formed and the physical adsorption but decreased the solid acidity and amount of chemisorption. (C) 2004 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.stam.2004.03.001

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  • Preparation and Properties of Glass-Ceramics from Wastes (Kira) of Silica Sand and Kaolin Clay Refining 査読

    Tomohiko Toya, Yoshikazu Kameshima, Atsuo Yasumori, Kiyoshi Okada

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   24 ( 8 )   2367 - 2372   2004年7月

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  • Preparation of Phase-Separated Textures and Crystalline Phases from Two-Liquid Immiscible Melts in the Ti02-Si02 System 査読

    Ken-ichi Katsumata, Yoshikazu Kameshima, Atsuo Yasumori, Kiyoshi Okada

    MATERIALS RESEARCH BULLETIN   39 ( 7-8 )   1131 - 1139   2004年6月

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  • Preparation and properties of CaO-MgO-Al2O3-SiO2 glass-ceramics from kaolin clay refining waste (Kira) and dolomite 査読

    T Toya, Y Tamura, Y Kameshima, K Okada

    CERAMICS INTERNATIONAL   30 ( 6 )   983 - 989   2004年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    CaO-MgO-Al2O3-SiO2 glass-ceramics were prepared from mixtures of waste generated from refining of kaolin clay (called Kira) and dolomite (CaMg(CO3)(2)). Kira was mixed with dolomite in mass ratios of 65/35 (sample 1) and 75/25 (sample 2). They were melted at 1350degreesC and quenched in water to obtain glasses. The quenched glasses were ground to <100 mesh and used to prepare glass-ceramics. Crystallization of the parent glass occurred above 900degreesC, producing diopside (CaMgSi2O6) and anorthite (CaAl2Si2O8) as major crystalline phases; diopside > anorthite in sample 1 and anorthite > diopside in sample 2. The macroscopic appearance of the samples changed from transparent pale green glass to smooth-textured shiny white upon crystallization. The four point bending strengths of the as-fired glass-ceramics were 130 MPa in sample 1 and 73 MPa in sample 2, which was approximately half of the value for sample 1. Vickers microhardness values were found to be 7.4 and 7.6 GPa in samples 1 and 2, respectively. The thermal expansion coefficients of the glass-ceramics prepared at 1000degreesC for 1 h were 6.7 x 10(-6)degreesC(-1) (30-380degreesC) in sample 1 and 4.7 x 10(-6)degreesC(-1) in sample 2. Since the chemical durability for acid and alkali was excellent in these glass-ceramics, they are considered to be candidates for applications such as building materials, ceramic tiles, etc. (C) 2003 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

    DOI: 10.1016/j.ceramint.2003.11.005

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  • Sorption properties of activated carbon derived from used paper and of amorphous 2CaO Al(2)O(3)2SiO(2) from paper sludge ash 査読

    K Okada, VK Jha, Y Kameshima, A Nakajima, KJD MacKenzie

    WASTE MANAGEMENT IN JAPAN   51 - 60   2004年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:WIT PRESS  

    Two materials with highly functional sorption properties were prepared from used paper and the paper sludge generated as a by-product of the process of paper production. Activated carbon can be prepared either by chemical activation using various chemical agents or by physical activation using steam. The chemically activated carbons show better porous properties than those obtained by physical activation. The activated carbon prepared using K2CO3 showed the highest specific surface area of about 1700 m(2)/g. This activated carbon showed very steep water vapour adsorption at 50 to 70% relative humidity with a maximum adsorption of >1000 ml/g. It also showed superior adsorption of methylene blue dye from solution. These adsorption properties make it a candidate material for humidity control and as a water purifying agent. An amorphous substance with 2CaO(.)Al(2)O(3)(.)2SiO(2) composition was prepared by mechanochemical and heat treatment of paper sludge at 500-800degreesC. Since these materials consist of three components with different chemical properties, they are able to take up heavy metal cations, NH4+ and PO43- ions, which are principally implicated in the eutrophication of lakes and ponds. Amorphous 2CaO(.)Al(2)O(3)(.)2SiO(2) obtained from paper sludge is therefore a candidate water purifying material and also has potential for soil recovery applications.

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  • Properties of glass-ceramics prepared from Kira (waste by-products of silica sand and kaolin clay refining) and various additives 査読

    K Okada, T Toya, Y Kameshima, A Nakajima

    WASTE MANAGEMENT IN JAPAN   11 - 19   2004年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:WIT PRESS  

    Five different glass-ceramics were prepared from Kira (waste by-products from processing of silica sand and kaolin clay) with various additives. Mixtures of Kira with CaCO3 (mass ratio 62.7/37.3, designated sample CC), dolomite (mass ratio 65/35, CM1) and mass ratio 75/25 (CM2), and paper sludge ash waste (mass ratio 55/45, PS) were melted at 1350-1400degreesC, quenched in water and ground to <48 mesh. Glass-ceramic samples were prepared by re-firing these powders at 950-1100degreesC. The main crystalline phases formed were wollastonite in CC, diopside (in CM1), anorthite (in CM2), quartz solid solution (in PS fired at 1000degreesC, designated PS1) and cristobalite (in PS fired at 1100degreesC, designated PS2). All these glass-ceramics showed a smooth-textured shiny white appearance and had very good mechanical properties; their four point bending strengths ranged from 63 to 130 MPa and Vickers microhardness values ranged from 6.0 to 7.6 GPa. Their thermal expansion coefficients ranged from 4.7x10(-6) to 8.1 x 10(-6) /degreesC and their chemical durabilities towards acid (1mass% H2SO4 at 90degreesC) were in the range 3.6x10(-9) to 93x10(-9) g/(cm(2.)s). Their resistance to alkali (1mass% NaOH at 90degreesC) ranged from 8.2x10(-9) to 27x10(-9) g/(cm(2.)s). The chemical durability of these glass-ceramics is better than that in commercial glass-ceramics used as building materials. Kira waste is therefore a promising candidate raw material for glass-ceramic building materials, ceramic tiles, etc.

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  • Effects of grinding and firing conditions on CaAl(2)Si(2)O(8) phase formation by solid-state reaction of kaolinite with CaCO(3) 査読

    K Okada, N Watanabe, KV Jha, Y Kameshima, A Yasumori, KJD MacKenzie

    APPLIED CLAY SCIENCE   23 ( 5-6 )   329 - 336   2003年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    The effects of grinding and firing conditions on CaAl(2)Si(2)O(8) phase fort-nation by solid-state reaction of kaolinite with CaCO(3) were investigated by differential thermal analysis (DTA)-thermogravimetry (TG), X-ray powder diffraction (XRD) and (29)Si and (27)Al MAS NMR. Unground and ground samples showed similar crystallization behavior at about 850 degreesC, and the crystallizing temperature was relatively unaffected by grinding. On the other hand, the crystalline products were strongly influenced by the grinding. Gehlenite (Ca(2)Al(2)SiO(7)) was the dominant phase in the unground samples but layer-structured CaAl(2)Si(2)O(8) was dominant in the ground samples, together with a small amount of anorthite, which is the stable phase. The amount of anorthite gradually increased with higher firing temperature, the sample fired at 1000 degreesC being almost completely anorthite. Grinding treatment before firing was effective in accelerating the decomposition of CaCO(3) and extending the temperature range for the formation of CaAl(2)Si(2)O(8), a phase with local structure similar to that of layered CaAl(2)Si(2)O(8). 2003 Elsevier B.V. All rights reserved.

    DOI: 10.1016/S0169-1317(03)00132-7

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  • Uptake of Various Cations by Amorphous BaAl2Si2Oδ Prepared by Solid-State Reaction of Kaolin with BaCO3 査読

    Kiyoshi Okada, Hiroyuki Arai, Yoshikazu Kameshima, Atsuo Yasumori, Kenneth, J.D Mackenzie

    MATERIALS LETTERS   57   3554 - 3559   2003年7月

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  • Crystallization Kinetics of Mullite from Polymeric Al2O3–SiO2 Xerogels 査読

    K. Okada, J. Kaneda, Y. Kameshima, A. Yasumori, T. Takei

    Mater. Lett.   57   3155 - 3159   2003年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • Porous properties of activated carbons from waste newspaper prepared by chemical and physical activation 査読

    K Okada, N Yamamoto, Y Kameshima, A Yasumori

    JOURNAL OF COLLOID AND INTERFACE SCIENCE   262 ( 1 )   179 - 193   2003年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    Activated carbons were prepared from old newspaper and paper prepared from simulated paper sludge by chemical activation using various alkali carbonates and hydroxides as activating reagents and also by physical activation using steam. In the chemical activation, the influence of oxidation, carbonization, and activation on the porous properties of the resulting activated carbons was investigated. The specific surface areas (S-BET) of the activated carbons prepared by single-step activation (direct activation without oxidation and carbonization) were higher than those resulting from two-step activation (oxidation-activation and carbonization-activation) and three-step activation (oxidation-carbonization-activation) methods. The SBET values were strongly dependent on the activating reagents and the activating conditions, being > 1000 m(2)/g using K2CO3, Rb2CO3, CS2CO3, and KOH as activating reagents but < 1000 m(2)/g using Li2CO3, Na2CO3, and NaOH. These differences in SBET values are suggested to be related to the ionic radii of the alkalis used as activating reagents. The microstructures of the higher S-BET samples show a complete loss of fiber shape but those of the lower S-BET samples maintain the shape. In the physical activation, the porous properties of the activated carbons prepared by the single-step method were examined as a function of the production conditions such as activation temperature, activation time, steam concentration, and flow rate of the carrier gas. The maximum SBET and total pore volume (V-P) were 1086 m(2)/g and 1.01 ml/g, obtained by activation at 850 degreesC for 2 h, flowing 20 mol% of steam in nitrogen gas at 0.51/min. A correlation was found between SBET and the yield of the product, the maximum SBET value corresponding to a product yield of about 10%. This result is suggested to result from competition between pore formation and surface erosion. Compared with chemically activated carbons using K2CO3, the porous properties of the physically activated carbons have lower S-BET and V-P values because of the smaller size and lower volume of their micropores. On the other hand, they retain the original fiber shape and the paper sheet morphology after activation. (C) 2003 Elsevier Science (USA). All rights reserved.

    DOI: 10.1016/S0021-9797(03)00107-3

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  • Mechanochemical processing of sialon compositions 査読

    KJD MacKenzie, J Temuujin, ME Smith, K Okada, Y Kameshima

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   23 ( 7 )   1069 - 1082   2003年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    Milling for 48 h in a sealed planetary ball mill was found to facilitate sialon formation in mixtures of aluminium and silicon oxides and nitrides on further heating in nitrogen at 1200-1600 degreesC. (27)Al and (29)Si MAS NMR indicated that milling exerts more influence on the oxide components than on the nitrides. Substitution of gamma-Al(2)O(3) by AI(OH)3 as the alumina source facilitated the mechanochemical formation of Si-O-Al bonds, as monitored by MAS NMR, but the subsequent thermal conversion of these precursors to stable aluminosilicates did not enhance sialon formation. Milled precursors of beta-sialon composition formed a mixture of beta, O and X-sialon, decomposing to polytypoid sialons at 1600 degreesC. Milled O-sialon precursors formed monophase O-sialon at 1600 degreesC, while some X-sialon compositions formed X-sialon at 1400 degreesC which decomposed to mullite and corundum at 1600 degreesC. A ground mixture of Ca alpha-sialon composition formed beta, O and X-sialons at 1600 degreesC, but no Ca sialon because of the depletion of Ca by the preferential formation of a Ca feldspar. Without milling, all these mixtures were unreactive, and generally did not form sialons on heating in nitrogen up to 1600 degreesC. (C) 2002 Elsevier Science Ltd. All rights reserved.

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  • Simultaneous uptake of ammonium and phosphate ions by composites of gamma-alumina/potassium aluminosilicate gel 査読

    K Okada, J Temuujin, Y Kameshima, KJD MacKenzie

    MATERIALS RESEARCH BULLETIN   38 ( 5 )   749 - 756   2003年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    The simultaneous uptake of ammonium and phosphate ions from solution by composites of gamma-alumina/potassium aluminosilicate (KAS) gel has been investigated. The composites were prepared by selective leaching of calcined kaolinite (Al(2)Si(2)O(5)(OH)(4)) using KOH solution, followed by neutralization of the leachate at pH 5.5 with nitric acid. The composites were reacted with solutions containing various concentrations of (NH(4))(2)HPO(4) at pH 5, 7 and 10 at room temperature for 24 h to examine their uptake of ammonium and phosphate ions. Simultaneous uptake of ammonium and phosphate ions was found, the uptake of ammonium ions being greater than for phosphate ions, especially at pH = 7. This observation is considered to result mainly from the porous properties of the composites, which should therefore be controlled to enhance the simultaneous uptake of both ions, especially phosphate ion. (C) 2003 Elsevier Science Ltd. All rights reserved.

    DOI: 10.1016/S0025-5408(03)00064-3

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  • Preparation of Fiber-reinforced Binderless Zeolite Disks in Solid State 査読

    C. D. Madhusoodana, Yoshikazu Kameshima, Atsuo Yasumori, Kiyoshi,Okada

    JOURNAL OF MATERIALS SCIENCE LETTERS   22   553 - 556   2003年4月

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  • Uptake of various cations by amorphous CaAl2Si2O8 Prepared by solid - state reaction of kaolinite with CaCO3 査読

    Nagisa Watanabe, Vinay K.Jha, Yoshikazu Kameshima, Atsuo Yasumori, Kemeth J.D Mackenzie

    JOURNAL OF MATERIALS CHEMISTRY   13 ( 3 )   550 - 556   2003年3月

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  • Adsorption Properties of Activated Carbon from Waste Newspaper Prepared by Chemical and Physical Activation 査読

    Kiyoshi Okada, Nobuo Yamamoto, Yoshikazu Kameshima, Atsuo Yasumori

    JOURNAL OF COLLOID AND INTERFACE SCIENCE   262   194 - 199   2003年1月

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  • Electrophoretic Deposition of Alumina on Stainless Steel Wire Net 査読

    Kiyoshi Okada, Fumikazu Hasegawa, Yoshikazu Kameshima, Atsuo Yasumori, Kiyoshi Okada

    Trans. Mat. Res. Soc. Jpn.   28 ( 2 )   361 - 364   2003年

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  • Effect of Crystallite Size of Boehmite on Sinterability of Alumina Ceramics 査読

    Kiyoshi Okada, Toru Nagashima, Yoshikazu Kameshima, Atsuo Yasumori

    CERAMICS INTERNATIONAL   29   533 - 537   2003年

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    記述言語:英語  

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  • Relationships between Formation Conditions , Properties and Crystallite Sizes of Boehmite 査読

    Kiyoshi Okada, Toru Nagashima, Yoshikazu Kameshima, Atsuo Yasumori, Takayuki Tsukada

    JOURNAL OF COLLOID AND INTERFACE SCIENCE   253 ( 2 )   308 - 314   2002年9月

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    記述言語:英語  

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  • Effect of Germanium Oxide(GeO2)Additive on the Anataseto-Rutile Phase Transition 査読

    Kiyoshi Okada, Ken-ichi Katsumata, Yoshikazu Kameshima, Atsuo Yasumori

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY   85 ( 8 )   2078 - 2082   2002年8月

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    記述言語:英語  

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  • Preparation and Porous Properties of Materials Prepared by Selective Leaching of Phlogopite 査読

    Kiyoshi Okada, Noriyuki Nakazawa, Yoshikazu Kameshima, Atsuo Yasumori, Jadambaa Temmujin, Kenneth, J.D.Mackenzie

    CLAYS AND CLAY MINERALS   50 ( 5 )   624 - 632   2002年5月

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  • Formation of hydroxyapatite on CaSiO3 powders in simulated body fluid 査読

    P Siriphannon, Y Kameshima, A Yasumori, K Okada, S Hayashi

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   22 ( 4 )   511 - 520   2002年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    CaSiO3 powders were prepared from ethanol solutions of Ca(NO3)(2)(.)4H(2)O and Si(OC2H5)(4) using NaOH as a precipitant. The resultant powders were heated at three different temperature regimes, (1) 500degreesC, (2) 500 and 1000degreesC and (3) 500 and 1400degreesC, to obtain the amorphous phase (amorphous-CS), low temperature phase (beta-CS), and high temperature phase (alpha-CS) of CaSiO3, respectively. The different amorphous and crystalline phases exhibited different microtextures and specific surface areas of the powders. The rough, porous particles of amorphous-CS and P-CS have higher specific surface areas than the smooth, dense particles of alpha-CS. These CaSiO3 powders were soaked in a simulated body fluid (SBF) at 36.5degreesC for 2 h to 30 days. Formation of hydroxyapatite (HAp) was observed on the surfaces of all samples, but the formation behavior and microstructures were different, resulting the differences in microstructure and crystal structure of the starting powders as well as particle size and specific surface area. The HAp formed on the amorphous-CS was a loose porous layer consisting of uniformly-sized tiny ball-like agglomerated particles, while that formed on the beta-CS and alpha-CS was a dense layer consisting of larger ball-like agglomerated particles. (C) 2002 Elsevier Science Ltd. All rights reserved.

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  • Acidic and Basic Gas Adsorption Properties in Composites of Layered Double Hydroxide/Aluminosilicate Xerogels 査読

    Kiyoshi Okada, Atsushi Kaneda, Yoshikazu Kameshima, Atsuo Yasumori

    Mat. Res. Bull.   37   209 - 219   2002年2月

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  • Effect of Crystallite Size on the Thermal Phase Change and Porous Properties of Boehmite 査読

    Kiyoshi OKADA, Toru NAGASHIMA, Yoshikazu KAMESHIMA, Atsuo YASUMORI

    J. COLLOID INTERFACE Sci.   248   111 - 115   2002年2月

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  • Magnetic Anisotropy of Phase-Separated CaO-Fe3O4-SiO2 Glasses Prepared from a Two-Liquids Immiscible Melt 査読

    Atsuo YASUMORI, Akio KOIKE, Yoshikazu KAMESHIMA, Kiyoshi OKADA, Hiroaki NISHIO

    J. NON-CRYSTALLINE SOLIDS   297   239 - 246   2002年

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  • Porous properties of polymeric Al2O3-SiO2 xerogels 査読

    K Okada, J Kaneda, Y Kameshima, A Yasumori, KJD MacKenzie

    EURO CERAMICS VII, PT 1-3   206-2   1945 - 1948   2002年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TRANS TECH PUBLICATIONS LTD  

    Polymeric Al2O3-SiO2 xerogels with chemical compositions of 9.4, 25, 60 and 80 mol% Al2O3 were prepared by a sol-gel method and their porous properties were examined by N-2 gas adsorption. Calculated amounts of aluminium nitrate nonahydrate (ANN) and tetraethylorthosilicate (TEOS) were dissolved in ethanol at a concentration of ANN+TEOS=0.3 mol/l with varying amount of added H2O, and hydrolyzed at 60 degreesC for 1 month. The resulting wet gels were dried at 110 degreesC then calcined at 300 degreesC to remove residual nitrates and organic matter. The specific surface areas of the four xerogels changed greatly with H2O/TEOS but the relation was different in each xerogel. The pores in all these xerogels were less than 2 mn in radius and were thus very different from colloidal xerogels, i.e. they can be tuned between 1 and 30 nm by changing the preparation conditions. The differences in pore sizes are caused by the difference in the pH of the solution and also by the sedimentation conditions which form agglomerated structures.

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  • Crystallization Kinetics of Mullite from Al2O3-SiO2 Glasses under Non-Isothermal Conditions 査読

    T. Takei, Y. Kameshima, A. Yasumori, K. Okada

    J. European Ceram. Soc.   21 ( 14 )   2487 - 2493   2001年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/S0955-2219(01)00266-7

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  • Effect of SiO2 Addition on the Anatase-to-Rutile Phase Transition 査読

    Kiyoshi OKADA, Nobuo YAMAMOTO, Yoshikazu KAMESHIMA, Atsuo YASUMORI, Kenneth J.D.MACKENZIE

    J. Am. Ceram. Soc.   84 ( 7 )   1591 - 1596   2001年7月

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  • SAXS Analysis of Textures Formed by Phase Separation and Crystallization of Al2O3-SiO2 Glasses 査読

    T. Takei, Y. Kameshima, A. Yasumori, K. Okada, N. Kumada, N. Kinomura

    J. Non-Crystalline Solids   282/3   265 - 267   2001年2月

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  • Preparation of ZSM-5 Thim Film on Cordierite Honeycomb by Solid State In-Situ Crystallization 査読

    Chengala. D. MADHUSOODANA, Rathindra N.DAS, Yoshikazu KAMESHIMA, Atsuo YASUMORI, Kiyoshi OKADA

    Microporous Mesoporous Mater.   46   249 - 255   2001年

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  • Photocatalytic and Photoelectrochemical Properties of TiO2-based Multiple Layer Thin Film Prepared by Sol-Gel and Reactive-Sputtering Methods 査読

    Atsuo YASUMORI, Hiroyuki SHINODA, Yoshikazu KAMESHIMA, Shigeo HAYASHI, Kiyoshi OKADA

    J. Mat. Chem.   11   1253 - 1257   2001年

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  • Fast Formation of ZSM-5 Zeolite using Microporous Silica Obtained from Selective Leaching of Metakaolinite 査読

    C.D.MADHUSOODANA, Yoshikazu KAMESHIMA, Atsuo YASUMORI, Kiyoshi OKADA

    Clay Science   11   369 - 380   2001年

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    記述言語:英語  

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  • Characterization and adsorption behavior of ZSM-5 zeolite film on cordierite honeycombs prepared by a novel in situ crystallization method 査読

    CD Madhusoodana, RN Das, Y Kameshima, A Yasumori, K Okada

    JOURNAL OF POROUS MATERIALS   8 ( 4 )   265 - 271   2001年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:KLUWER ACADEMIC PUBL  

    Thin films of ZSM-5 zeolite prepared on three types of cordierite ceramic honeycomb substrates by a novel in situ crystallization method were characterized by XRD, FTIR, XRF, SEM-EDX, NH3-TPD and propane gas adsorption to examine the effect of the substrate on various properties of the ZSM-5 films. The substrates were both as-prepared and acid treated cordierite honeycombs. The XRD, FTIR and XRF results showed that silica-rich surface layers were formed on the surface of the honeycombs by the acid treatments. The SiO2/Al2O3 ratios of the ZSM-5 zeolite formed on these layers increased with increasing time of acid treatment. Both Al2O3 and SiO2 from the substrates were found to contribute to the formation reaction of the zeolite films corresponding to the composition of the interfacial layer. The porous properties of the honeycomb substrates also varied in relation to the amount of zeolite film, which increased linearly with acid treatment time. The presence of the silica-rich interfacial layer between the substrate and zeolite film increased the amount of ZSM-5 and the physical adsorption but decreased the solid acidity and amount of chemisorption.

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  • Characterization of the state of Ni2+ in Ni-exchanged KAlSiO4 by XPS, XRF, XRD, EXAFS and NMR 査読

    K Okada, M Nemoto, Y Kameshima, Y Matsushima, KJD Mackenzie

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   108 ( 11 )   989 - 992   2000年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    Imperfectly ordered KAlSiO4 shows a greatly increased uptake of Ni2+ from solution which motivated this study of the state of Ni2+ in Ni-exchanged KAlSiO4 using X-ray photo-electron spectroscopy (XPS), X-ray fluorescence (XRF), powder X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS) and solid state nuclear magnetic resonance spectroscopy (NMR), The imperfectly ordered KAlSiO4 was synthesized by solid-state reaction of kaolinite with K2CO3 at 550 degreesC for 24 h. The Ni-exchanged KAlSiO4 samples were obtained by treatment in a solution containing 10(-3)-10(-1) M NiCl2 buffered with 0.5 M NaCl at 60 degreesC, Comparison of the surface and bulk chemical compositions analyzed by XPS and XRF indicated that the Ni2+ sorbed on the KAlSiO4 is largely concentrated at the surface. The XRD pattern of the Ni-exchanged KAlSiO4 showed weak broad peaks corresponding to a phase with a layered structure and a change in the halo pattern of the KAlSiO4. EXAFS analysis confirmed the presence of a Ni-containing layered double hydroxide (LDH; Ni1-yAly(OH)(2)X-y. nH(2)O) as indicated by the interatomic Ni-Ni distance and Ni coordination number. The Si-29 MAS NMR showed shift and peak splitting corresponding to an increase in the degree of polymerization of the SiO4 tetrahedra forming the framework of the tridymite-type structure and the Al-27 MAS NMR showed an increase of six coordinated Al in the Ni-exchanged KAlSiO4. It is concluded, from all these results, that the Ni2+ in Ni-exchanged KAlSiO4 forms a Ni-Al LDH-like phase on the surface of the KAlSiO4, This is considered to be the main reason for the higher Ni2+ uptake compared with various other cations adsorbed on imperfectly ordered KAlSiO4.

    DOI: 10.2109/jcersj.108.1263_989

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  • Influence of preparation conditions on the microstructure and bioactivity of alpha-CaSiO3 ceramics: Formation of hydroxyapatite in simulated body fluid 査読

    P Siriphannon, Y Kameshima, A Yasumori, K Okada, S Hayashi

    JOURNAL OF BIOMEDICAL MATERIALS RESEARCH   52 ( 1 )   30 - 39   2000年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JOHN WILEY & SONS INC  

    Two different reagents, NaOH and NH4OH, were used to precipitate CaSiO3 precursor powders from ethanol solutions of Ca(NO3)(2) . 4H(2)O and Si(OC2H5)(4). The resultant powders of different Ca/Si ratio and residual Na2O content exhibited significant differences in the microtexture of the resulting sintered alpha-CaSiO3 ceramics. The microtexture of the ceramics from the NaOH system (CS-Na) contained smaller grain sizes and a thicker glassy phase at the grain boundaries than those produced using NH4OH (CS-NH). The CS-Na ceramics were soaked in a simulated body fluid (SBF) at 36.5 degrees C for 2 h and 1, 5, 6, 10, 21, and 30 days while the CS-NH ceramics were soaked for 1, 5, 7, 15, 20, and 25 days using the same conditions. Hydroxyapatite (HAp) formed on the surfaces of both samples but at different formation rates due to differences in the microstructure. The CS-Na ceramics showed faster HAp formation because their smaller alpha-CaSiO3 grains dissolved more readily, allowing the calcium concentration in the SBF quickly to approach the appropriate condition for nucleation of HAp. In addition, the thicker glassy phase at the grain boundaries facilitated a faster formation of silanol on the surface of the amorphous SiO2 interlayer, a reaction that is considered to be a prerequisite for HAp formation. The formation of the HAp layer on the CS-Na ceramics therefore was very fast (12 mu m/ day), and their surfaces were covered completely within 5 days. A layer thickness of about 110 mu m was achieved in 30 days, in contrast with the CS-NH ceramics, which took about 25 days to be fully covered with a 60-mu m layer of HAp. (C) 2000 John Wiley & Sons, Inc.

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  • Uptake of various cations by imperfectly ordered KAlSiO4 prepared by solid-state reaction of kaolinite with K2CO3 査読

    K Okada, M Nemoto, Y Kameshima, A Yasumori

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   108 ( 10 )   898 - 903   2000年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    The uptake of various cations by imperfectly ordered KAlSiO4 was investigated. The KAlSiO4 was prepared by solid-state reaction of kaolinite with K2CO3 at 550 degreesC for 24 h. Uptake experiments Lt ere performed at 60 degreesC using 0.5 g of the KAlSiO4 and 50 mi of solution containing 10(-3)-10(-1) M of each cation, with and without 0.5 M NaCl buffer, The cations were alkali (Li+ and Na+), alkaline earth (Mg2+, Ca2+, Sr2+ and Ba2+) and transition metal cations (Ni2+, Co2+, Cu2+ and Zn2+). From the comparison of uptakes of various cations bg KAlSiO4 and zeolite Na-A, it was found that the ratio of uptake by both exchange materials increased with decreasing ionic radius of the exchanging cations, the KAlSiO4 showing higher uptake of Ni2+ than zeolite Na-A, This trend became more distinct for the uptake of Ni2+ in simulated acid waste solution and groundwater because of the suppressing effects by co-existing alkali and alkaline earth cations especially for zeolite Na-A.

    DOI: 10.2109/jcersj.108.1262_898

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  • Morphology control of phase-separation texture by elongation of two-liquids immiscible melt in Fe3O4-SiO2 system 査読

    A Yasumori, A Koike, Y Kameshima, K Okada, S Inoue

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   108 ( 9 )   813 - 817   2000年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    The existence of a liquid-liquid miscibility gap in Fe3O4-SiO2 system has been reported. In this study, phase-separated glasses of 5 Fe3O4. 95SiO(2) (mol%) were prepared by melting sintered rods of the same composition at 1800 degrees C (in immiscible region) using an infrared imaging furnace and, subsequently, quenching with elongation of the melts at a constant rate. The glass quenched without elongation exhibited a binodal type phase separation texture consisting of discrete spherical Fe3O4-rich particles. On the contrary, in the sample quenched with elongation, Fe3O4-rich particles were stretched and oriented along the direction of elongation, The length of the stretched particles was proportional to the elongation distance and was not independent of the elongation rate within short elongation distance. However, the stretching of the particles was less pronounced for the long elongation ranges. This suggests that the spherical particles grown by phase separation in the binodal region, were stretched by viscous flow in the early stage of elongation and the stretching in the latter stage was reduced by restoration due to viscoelastic behavior and/or to a steep increase of viscosity. The deformation and orientation of phase separation texture could be achieved in this process, though this deformation proceeded under non-equilibrium conditions. Therefore, the operated elongation process of two-liquid immiscible melts may enable one to fabricate high-functional composite materials owing to morphology control of phase separation texture.

    DOI: 10.2109/jcersj.108.1261_813

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  • XPS and X-ray AES (XAES)Study of Various Aluminate Compounds 査読

    Yoshikazu KAMESHIMA, Atsuo YASUMORI, Kiyoshi OKADA

    J. Surf. Sci. Soc. Jpn.   21 ( 8 )   481 - 487   2000年8月

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  • In-Situ Zeolite X Coating on Glass Fibers by Soft Solution-Process 査読

    K. Okada, K, Kuboyama, T. Takei, Y. Kameshima, A. Yasumori, M. Yoshimura

    Microporous and Mesoporous Mater.   37   99 - 105   2000年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • Effect of monovalent cation additives on the gamma-Al2O3-to-alpha-Al2O3 phase transition 査読

    K Okada, A Hattori, Y Kameshima, A Yasumori, RN Das

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY   83 ( 5 )   1233 - 1236   2000年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CERAMIC SOC  

    The effect of monovalent cation addition on the gamma-Al2O3-to-alpha-Al2O3 phase transition was investigated by differential thermal analysis, powder X-ray diffractometry, and specific-surface-area measurements. The cations Li+, Na+, Ag+, K+, Rb+, and Cs+ were added by an impregnation method, using the appropriate nitrate solution. beta-Al2O3 was the crystalline aluminate phase that formed by reaction between those additives and Al2O3 in the vicinity of the gamma-to-alpha-Al2O3 transition temperature, with the exception of Li+, The transition temperature increased as the ionic radii of the additive increased, The change in specific surface area of these samples after heat treatment showed a trend similar to that of the phase-transition temperature, Thus, Cs+ was concluded to be the most effective of the present monovalent additives for enhancing the thermal stability of gamma-Al2O3. Because the order of the phase-transition temperature coincided with that of the formation temperature of beta-Al2O3 in these samples, suppression of ionic diffusion in gamma-Al2O3 by the amorphous phase containing the added cations must have played an important role in retarding the transition to alpha-Al2O3. Larger cations suppressed the diffusion reaction more effectively.

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  • Thermal stability of coprecipitated Al2O3-SiO2 xerogels prepared from aluminium nitrate nonahydrate and tetraethylorthosilicate 査読

    K Okada, T Tomita, Y Kameshima, A Yasumori

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   108 ( 2 )   122 - 127   2000年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    Amorphous Al2O3-SiO2 xerogels were prepared by coprecipitation and their thermal stability was investigated by powder X-ray diffraction, N-2 gas adsorption and transmission electron microscopy, Xerogels with chemical compositions of 4, 30, 60, 80 and 100 mol%Al2O3 were prepared by adding cone. NH4OH to an ethanol solution of aluminium nitrate nonahydrate (ANN) and tebraethylorthosilicate (TEOS), Deionized water was added to the solution to adjust the molar ratio H2O/TEOS greater than or equal to 18. The xerogels obtained by calcining at 300 degrees C were heat-treated at 800-1500 degrees C for 2 h at heating and cooling rates of 10 degrees C/min, The specific surface area (S-A) of the xerogels heated at high temperatures showed large composition-dependent variations, the samples containing 60 and 80 mol%Al2O3 having much higher S-A values than the other xerogels, This is attributed to retarding effect of the SiO2 component for transition into alpha-Al2O3 phase by avoiding direct contact of gamma-Al2O3 particles. On the other hand, the S-A values of the SiO2-rich and Al2O3 xerogels decreased markedly at about 1000-1100 degrees C with increasing of pore radius (r(P)). This steep decrease in S-A and increase of r(P) are attributed mainly to densification by a viscous flow mechanism accompanied by abrupt particle growth in the SiO2-rich xerogels and by a particle growth mechanism accompanied by the gamma-to-alpha-Al2O3 phase transition in the Al2O3 xerogel, The thermal stability of the xerogels is compared with those of other previously reported porous ceramics.

    DOI: 10.2109/jcersj.108.1254_122

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  • Calculation of Metastable Immiscibility Region in the Al2O3-SiO2 System Using Molecular Dynamics Simulation 査読

    T. Takei, Y. Kameshima, A. Yasumori, K. Okada

    J. Mater. Res.   15 ( 1 )   186 - 193   2000年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1557/JMR.2000.0030

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  • Concentration effect of Cs+ additive on the gamma-Al2O3-to-alpha-Al2O3 phase transition 査読

    K Okada, A Hattori, Y Kameshima, A Yasumori

    MATERIALS LETTERS   42 ( 3 )   175 - 178   2000年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    The effect of Cs+ additive on the gamma-Al2O3-to-alpha-Al2O3 phase transition was investigated as a function of the Cs+ concentration by powder X-ray diffraction and specific surface area (S-A) measurements. The addition of Cs+ increasingly retarded the gamma-to-alpha phase transition with increasing Cs+ concentration, reading a maximum at 5% addition, at which the transition temperature was increasing by about 200 degrees C. This Cs+ concentration corresponds to an amount of cation which would almost fully cover the surface of the gamma-Al2O3 grains. (C) 2000 Elsevier Science B.V. All rights reserved.

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  • Magnetooptical Property of Sodium Borosilicate Gel-Glass Containing Bi-YIG Fine Particles 査読

    Atsuo YASUMORI, Tomokazu KATSUYAMA, Yoshikazu KAMESHIMA, Kiyoshi OKADA

    J. Sol-Gel Sci. Tech.   19   813 - 817   2000年

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    記述言語:英語  

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  • Effect of Preparation Conditions on Porous Properties of Coprecipitated A12O3-SiO2 Xerogels Prepared from Aluminium Nitrate Nonahydrate and Tetraethylorthosilicate 査読

    Kiyoshi OKADA, Takahiro TOMITA, Yoshikazu KAMESHIMA, Atsuo YASUMORI, Kenneth J, D. MACKENZIE

    Microporous Mesoporous Mater.   37   355 - 364   2000年

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    記述言語:英語  

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  • Sol-gel synthesis of YAC/Al2O3 long fibres from water solvent systems 査読

    K Okada, T Motohashi, Y Kameshima, A Yasumori

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   20 ( 5 )   561 - 567   2000年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    Y3Al5O12(YAG)/Al2O3 long fibres were prepared by a sol-gel method using water as the solvent. They were synthesized from aluminium nitrate and chloride solutions, aluminium salt, aluminium metal and Y2O3. The starting materials were dissolved by refluxing at 100 degrees C for 2-18 h and were then condensed. The fibre spinnability was examined by a hand drawing method using a glass rod. In the nitrate solution system, the composition range available for fibre preparation was very limited because nitrate ions decomposed during the refluxing, raising the solution pH and precipitating the Y component. On the other hand, the composition range of the fibres prepared from the chloride system was 0/10 less than or equal to YAG/Al2O3 less than or equal to 6/4 (volume ratio) and was wider than that from the nitrate system. The YAG/Al2O3 fibres prepared by firing at 1300 degrees C became denser with faster heating rates. The grain size in the fired fibres was small, below the firing temperature at 1400 degrees C, but increased greatly above that temperature. (C) 2000 Elsevier Science Ltd. All rights reserved.

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  • Nitridation of silicon powder studied by XRD, (29)Si MAS NMR and surface analysis techniques 査読

    KJD MacKenzie, CM Sheppard, K Okada, Y Kameshima

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   19 ( 16 )   2731 - 2737   1999年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    The nitridation of elemental silicon powder at 900-1475 degrees C was studied by X-ray photoelectron spectroscopy (XPS), X-ray excited Auger electron spectroscopy (XAES), XRD, thermal analysis and (29)Si MAS NMR. An initial mass gain of about 12% at 1250-1300 degrees C corresponds to the formation of a product layer about 0.2 mu m thick (assuming spherical particles). XPS and XAES show that in this temperature range, the surface atomic ratio of N/Si increases and the ratio O/Si decreases as the surface layer is converted to Si(2)N(2)O. XRD shows that above 1300 degrees C the Si is rapidly converted to a mixture of alpha-and beta-Si(3)N(4), the latter predominating > 1400 degrees C. In this temperature range there are only slight changes in the composition of the surface material, which at the higher temperatures regains a small amount of an oxidised surface layer. By contrast, in the interval 1400-1475 degrees C, the (29)Si MAS NMR chemical shift of the elemental Si changes progressively from about -80ppm to -70ppm, in tandem with the growth of the Si(3)N(4) resonance at about -48ppm. Possible reasons for this previously unreported change in the Si chemical shift are discussed. (C) 1999 Elsevier Science Ltd. All rights reserved.

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  • Crystallization Kinetics of Mullite in Al2O3-SiO2 Glass Fibers 査読

    T. Takei, Y. Kameshima, A. Yasumori, K. Okada

    J. Am. Ceram. Soc.   82 ( 10 )   2876 - 2880   1999年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1111/j.1151-2916.1999.tb02171.x

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  • In situ temperature measurement of oxide melt in an are imaging furnace by a monochromatic radiation pyrometer 査読

    A Yasumori, J Hama, T Yang, S Shibata, M Yamane, S Inoue, N Nakazawa, Y Kameshima, K Okada

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   107 ( 10 )   986 - 989   1999年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    An are imaging furnace has various advantages as an apparatus for ceramic synthesis. However, the disadvantage of this furnace is the difficulty of in situ temperature measurement of the sample, because of a very small heating spot in the furnace and the effect of infrared radiation from the light source on the measurement, a monochromatic radiation pyrometer is used. In this paper, a technique for in situ temperature measurement by monochromatic radiation pyrometer is proposed and applied to the melts of a CaO-SiO2 system above 1700 degrees C. Keating up was performed in an are imaging furnace equipped with a Xenon lamp. The monochromatic radiation pyrometer was proven to work appropriately for in situ temperature measurement of the melting samples above 1750 degrees C, because it can focus on a small melting drop 2-3 mm in diameter, and also because it can avoid the effect of infrared radiation horn the Xe lamp, by using a 5 mu m wavelength to detect the radiation from the sample melts.

    DOI: 10.2109/jcersj.107.986

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  • Porous Properties of Co-precipitated A12O3-SiO2 Xerogels Prepared from Aluminium Nitrete Nonahydrate and Tetraethylorthosilicate 査読

    Kiyoshi OKADA, Takahiro TOMITA, Yoshikazu KAMESHIMA, Atsuo YASUMORI, Kenneth J, D. MACKENZIE

    J.Mater.Chem.   9 ( 6 )   1307 - 1312   1999年

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    記述言語:英語  

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  • Surface Acidity and Hydrophilicity of Coprecipitated A12O3-SiO2 Werogels Prepared from Aluminium Nitrate Nonahydrate and Teraethylorthosilicate 査読

    Kiyoshi OKADA, Takahiro TOMITA, Yoshikazu KAMESHIMA, Atsuo YASUMORI, Kenneth J, D. MACKENZIE

    J.Colloid Interface. Sci.   219   195 - 200   1999年

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    記述言語:英語  

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  • Analysis of surface state and stability during storage of AIN powders by X-ray photoelectron spectroscopy 査読

    Y Kameshima, S Kuramochi, A Yasumori, K Okada

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   106 ( 8 )   749 - 753   1998年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    The surface state of as-prepared AIN powders produced by direct nitridation and carbothermal methods was characterized by X-ray photoelectron spectroscopy (XPS) and X-ray excited Auger electron spectroscopy (XAES), In the as-prepared AlN powders, small peaks assigned to imide and amide groups were detected in the N1s XPS spectra of directly nitrided powders but not in those of the carbothermally treated powders. Both an oxidized surface phase and a parent AIN phase could be distinguished in the A12p XPS and Al (KLL) XAES spectra of all the samples. The structural state of the oxidized surface phase was found to be similar to gamma-Al2O3. The average thickness of the oxidized surface phase was determined to be about 0.5-0.6 nm in directly nitrided AlN powders whereas it was 1.1 nm in carbothermally treated AIN powders. The thickness of the oxidized surface phase increased with increasing storage times of the AIN powders in a container under ambient atmosphere. The increase of thickness with storage time of the oxidized surface phase in directly nitrided AlN powder was faster than in the carbothermally treated AIN powder. The oxidized surface phase changed from gamma-Al2O3 in the as-prepared AlN powders to a hydroxide phase during storage.

    DOI: 10.2109/jcersj.106.749

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  • Chemical shifts of silicon X-ray photoelectron spectra by polymerization structures of silicates 査読

    K Okada, Y Kameshima, A Yasumori

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY   81 ( 7 )   1970 - 1972   1998年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CERAMIC SOC  

    The binding energy of Si 2p electrons and the kinetic energy of the Si(KLL) X-ray-excited state were measured by using X-ray photoelectron spectroscopy (XPS) and X-ray Auger electron spectroscopy (XAES), respectively, for silicates with SiO4 tetrahedra of various polymerization types. The resulting Si 2p XPS binding energies varied from 101.3 eV in merwinite (monomeric structure) to 103.4 eV in quartz and cristobalite (three-dimensional framework structure). A clear chemical-shift relation was observed, relating the polymerization structures of SiO4 tetrahedra to the plots of their Si 2p XPS binding energy versus the kinetic energy of their SI(KLL) XAES spectra, Thus, the structural state of the surface silicates in various substances can be deduced from this chemical-shift relationship.

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  • Liquid-liquid phase separation of melts and glasses in ferric ferrous oxide-silica system 査読

    A Yasumori, A Koike, Y Kameshima, K Okada, T Yano, M Yamane, S Inoue

    STRUCTURE AND DYNAMICS OF GLASSES AND GLASS FORMERS   455   459 - 464   1997年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:MATERIALS RESEARCH SOCIETY  

    The existence of liquid-liquid miscibility gap in ferric ferrous oxide-silica system has been reported, however, the phase separation phenomena and the derived morphology of the phase separated glasses are uncertain. In this study, the melt-quenched samples of 5 Fe3O4-95 SiO2 and 15 Fe3O4-85 SiO2 (mol%) were prepared by melting at 2300 degrees C or 2200 degrees C (expected to be above miscibility gap), and subsequently at 1800 degrees C or 1750 degrees C (in immiscible region) by use of infrared image furnace and quenching at the rate of approximate to 10(2) K/sec. The glassy materials exhibited phase separation having discrete spherical particles or interconnected structure due to the composition, melting temperature and time. Also, the segregation of Fe component occurred during melting, which was caused by the difference of specific gravity of components in the melt.

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  • CHARACTERIZATION OF SURFACE-OXIDIZED PHASE IN SILICON-NITRIDE AND SILICON OXYNITRIDE POWDERS BY X-RAY PHOTOELECTRON-SPECTROSCOPY 査読

    K OKADA, K FUKUYAMA, Y KAMESHIMA

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY   78 ( 8 )   2021 - 2026   1995年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CERAMIC SOC 735 CERAMIC PLACE  

    Surface-oxidized phases on alpha-silicon nitride, beta-silicon nitride, and silicon oxynitride powders were investigated by X-ray photoelectron spectroscopy (XPS) and X-ray Anger electron spectroscopy (XAES). The spectra of Si2p XPS and Si(KLL) XAES were measured precisely and were deconvoluted into some separate peaks, which correspond to each parent phase, a SiOxNy oxidized phase, a nonstoichiometric SiNx nitride phase, and a satellite peak of the parent phase, by the least-squares method. The Auger parameter (AP) was calculated for each phase using the Si2p XPS and Si(KLL) XAES data, and the average chemical compositions of the oxidized phases in each sample were evaluated from the AP data. The chemical compositions of these phases mere between those of silica and silicon oxynitride and varied among the samples, but were usually close to SiO2. Average thicknesses of the surface-oxidized phases were estimated to be 0.1-0.8 nm from the peak area ratio of the oxidized phase against the parent phase of the XAES spectra, assuming a continuous surface layer model.

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  • PREPARATION OF Y-TZP/AL2O3 WHISKER PREFORM BY AN IN-SITU METHOD 査読

    K OKADA, Y KAMESHIMA, H MUTOH, S HAYASHI

    JOURNAL OF MATERIALS SCIENCE   29 ( 15 )   4081 - 4085   1994年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CHAPMAN HALL LTD  

    In situ growth of Al2O3 Whiskers into the matrix of Y-TZP (yttria-doped tetragonal zirconia polycrystals) was examined in order to prepare Y-TZP/Al2O3 whisker preform for the composites. Various shapes of Al2O3 particles were grown by the reaction of Al2O3 and AlF3 powders with moist nitrogen or oxygen gases at high temperature. They showed a trend to change the particle shapes from massive --> rhombohedron --> whisker --> platelet as the processing temperature was increased. These particles, however, grew only on the surface and not inside the pellets It was found necessary to introduce the carrier gas inside the pellets for particle growth to occur internally. Al2O3 whiskers can be synthesized inside the pellets by mixing with an organic space-forming agent having a relatively large particle size.

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▼全件表示

書籍等出版物

  • セラミックス機能化ハンドブック

    NTS  2011年  ( ISBN:9784860433505

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  • エコマテリアルハンドブック

    丸善  2006年 

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MISC

  • 再利用できる酸化チタン系油水分離フィルター 査読

    西本俊介, 亀島欣一, 三宅通博

    加工技術   53   149 - 152   2018年

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  • 層状複水酸化物ゲル体からの水浄化のための多孔体の作製

    亀島欣一, 渡辺駿一, 西本俊介, 三宅通博, 田中俊行

    日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM)   29th   2016年

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  • 層状複水酸化物を利用した新規水処理触媒の開発

    亀島欣一

    研究レポート集2014   ( 15 )   67 - 72   2014年

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  • ハイドロタルサイトの組成分析に活用できる赤外吸収スペクトルのピーク分離法

    田中俊行, 玉井博康, 亀島欣一, 西本俊介, 三宅通博

    粘土科学討論会講演要旨集   58th   2014年

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  • 41 水酸アパタイトによる土壌中のカドミウムの形態変化(関西支部講演会,2012年度各支部会)

    三瀬 千暁, 西本 俊介, 亀島 欣一, 三宅 通博

    日本土壌肥料学会講演要旨集   ( 59 )   300 - 300   2013年9月

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    記述言語:日本語   出版者・発行元:一般社団法人日本土壌肥料学会  

    CiNii Article

    CiNii Books

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  • 軽量気泡コンクリート材を利用したセシウムイオン交換材料の開発

    亀島 欣一, 堤 卓馬, 西本 俊介, 三宅 通博

    イオン交換学会誌   24 ( 2 )   46 - 51   2013年

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  • 赤外吸収スペクトルのピーク分離による層状複水酸化物の層間イオンの定量法

    田中俊行, 亀島欣一, 西本俊介, 三宅通博

    日本化学会講演予稿集   93rd ( 2 )   2013年

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  • 赤外吸収スペクトルのピーク分離によるハイドロタルサイトの層間イオンの定量法

    田中俊行, 亀島欣一, 西本俊介, 三宅通博

    粘土科学討論会講演要旨集   57th   2013年

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  • 層状ペロブスカイトの中温作動固体酸化物燃料電池用カソード電極特性 (特集 燃料電池に関連する基礎研究(1))

    三宅 通博, 西本 俊介, 亀島 欣一

    燃料電池   13 ( 2 )   7 - 14   2013年

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    記述言語:日本語   出版者・発行元:燃料電池開発情報センター  

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  • 炭酸型層状複水酸化物のモノカルボン酸非水溶液を用いた陰イオン交換における溶媒効果

    田中俊行, 亀島欣一, 西本俊介, 三宅通博

    日本化学会講演予稿集   93rd ( 2 )   2013年

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  • 環境材料としてのゼオライト

    三宅 通博, 松田 元秀, 亀島 欣一, 西本 俊介

    セラミックス   47 ( 5 )   354 - 360   2012年

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  • カルボン酸/アルコール溶液中のカルボン酸層状二重水酸化物のアニオン交換反応

    TANAKA T., KAMESHIMA Y., NISHIMOTO S., MIYAKE M.

    セラミックス基礎科学討論会講演要旨集   50th   2012年

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  • 炭酸型層状複水酸化物のカルボン酸/アルコール溶液を用いた陰イオン交換反応における溶媒効果

    田中俊行, 亀島欣一, 西本俊介, 三宅通博

    日本化学会講演予稿集   92nd ( 2 )   2012年

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  • これだけは知っておきたい合成の基礎1:微粉末合成

    亀島欣一

    平成23年度セラミックス大学 ベーシックコーステキスト   49 - 63   2011年

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  • 未燃炭素含有石炭灰からの活性炭/ゼオライト複合体の合成と吸着特性

    田中俊行, 西本俊介, 亀島欣一, 三宅通博

    粘土科学討論会講演要旨集   55th   2011年

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  • レイヤーバイレイヤー法を用いた層状複水酸化物ナノシート/デンドリマー積層薄膜の作製

    田中俊行, 西本俊介, 亀島欣一, 高口豊, 三宅通博

    日本化学会講演予稿集   91st ( 2 )   2011年

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  • Asian Clay報告

    亀島欣一, 川俣純, 高木慎介, 松枝直人, 福士圭介, 山田裕久

    粘土科学   49 ( 2 )   53 - 61   2010年

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  • 光応答デンドリマー/層状複水酸化物複合体の合成と取込量に対するpHの影響

    田中俊行, 西本俊介, 亀島欣一, 高口豊, 三宅通博

    粘土科学討論会講演要旨集   54th   2010年

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  • LbL法を用いたLDH/機能性デンドリマーハイブリッド薄膜の作製

    田中俊行, 西本俊介, 亀島欣一, 高口豊, 三宅通博

    セラミックス基礎科学討論会講演要旨集   48th   2010年

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  • Characteristics of microbubbles Generated by Porous Mullite Ceramics Prepared by an Extrusion Method Using Orgtanic Fibers as the Pore Former

    Koyoshi OKADA, Mai Shimizu, Toshihiro ISOBE, Yoshikazu KAMESHIMA, Munetoshi SAKAI, Akira NAKAJIMA, Taisuke KURATA

    J. Eur. Ceram. Soc.   30 ( 6 )   1245 - 1251   2010年

  • Instrument for ceramic particle dispersion

    Toshihiro Isobe, Asami Ooyama, Yoshikazu Kameshima, Akira Nakajima, Kiyoshi Okada

    Powder Technology   200 ( 1-2 )   25 - 29   2010年

  • 層状複水酸化物のデンドリマーに対するイオン交換特性;pH応答性

    田中俊行, 西本俊介, 亀島欣一, 高口豊, 三宅通博

    日本化学会講演予稿集   90th ( 2 )   2010年

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  • Nanosized silver-anionic clay matrix as nanostructured ensembles with antimicrobial activity

    Gabriela Carja, Yoshikazu Kameshima, Akira Nakajima, Cristian Dranca, Kiyoshi Okada

    INTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS   34 ( 6 )   534 - 539   2009年12月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Nanostructured ensembles of silver nanoparticles/zinc-substituted anionic clay matrix (Ag/ZnLDH) were obtained by a simple synthetic route in which reconstruction of the layered clay, synthesis of the silver nanoparticles and their organisation on the clay surface took place in a single step at room temperature. The morphology, composition and phase structure of the prepared powders were characterised by X-ray diffraction, infrared spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and N(2) adsorption. Results showed that the silver-anionic clay nanoarchitecture consists of nanoparticles of silver (average size 7 nm) deposited on the larger nanoparticles of clay (average size 85 nm). The antimicrobial activity was examined by disk diffusion assay and minimal inhibitory concentration determination as a function of x, where x is a controlled variable parameter that represents the length of time since the sample was synthesised. Ag/ZnLDH showed more stable antimicrobial properties than the unsupported nanosized silver. (C) 2009 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

    DOI: 10.1016/j.ijantimicag.2009.08.008

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  • Nanosized silver-anionic clay matrix as nanostructured ensembles with antimicrobial activity

    Gabriela Carja, Yoshikazu Kameshima, Akira Nakajima, Cristian Dranca, Kiyoshi Okada

    INTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS   34 ( 6 )   534 - 539   2009年12月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Nanostructured ensembles of silver nanoparticles/zinc-substituted anionic clay matrix (Ag/ZnLDH) were obtained by a simple synthetic route in which reconstruction of the layered clay, synthesis of the silver nanoparticles and their organisation on the clay surface took place in a single step at room temperature. The morphology, composition and phase structure of the prepared powders were characterised by X-ray diffraction, infrared spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and N(2) adsorption. Results showed that the silver-anionic clay nanoarchitecture consists of nanoparticles of silver (average size 7 nm) deposited on the larger nanoparticles of clay (average size 85 nm). The antimicrobial activity was examined by disk diffusion assay and minimal inhibitory concentration determination as a function of x, where x is a controlled variable parameter that represents the length of time since the sample was synthesised. Ag/ZnLDH showed more stable antimicrobial properties than the unsupported nanosized silver. (C) 2009 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

    DOI: 10.1016/j.ijantimicag.2009.08.008

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  • Preparation of Pt particles dispersing nanocomposites by thermal treatment of tetrachloroplatinate/layered double hydroxide (LDH)

    Yoshikazu Kameshima, Akira Nakajima, Kiyoshi Okada, Toyohiko Yano

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   117 ( 1371 )   1229 - 1232   2009年11月

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    記述言語:英語   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    Mg-Al LDH intercalated PtCl42- anion (PtCl4-LDH) was synthesized by a reconstruction method using potassium tetrachloroplatinate and its thermal changes were investigated at various temperatures. The PtCl4-LDH included 17 mass% Pt was synthesized by a reconstruction method using K2PtCl4 Solution of 10 mM to adjust the pH with NaOH to about 11. The obtained PtCl4-LDH shows high crystallinity and has low content of CO32-. The basal spacing of the obtained PtCl4-LDH was 0.83 nm expanding slightly from 0.78 nm of starting LDH. The XRD patterns of the obtained PtCl4-LDH showed that the second 001 diffraction line (006) became more accentuated than the first one (003) according to the intercalation of Pt components. Pt fine particles in the several nm were directly observed by TEM after firing at 500 degrees C. However, the diffraction patterns of Pt or Pt components were not detected via XRD in the same sample. This is due to the coagulation of Pt components by the narrow basal spacing of the PtCl4-LDH. (C) 2009 The Ceramic Society of Japan, All rights reserved.

    DOI: 10.2109/jcersj2.117.1229

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  • Preparation and properties of negative thermal expansion Zr2WP2O12 ceramics

    Toshihiro Isobe, Takuya Umezome, Yoshikazu Kameshima, Akira Nakajima, Kiyoshi Okada

    MATERIALS RESEARCH BULLETIN   44 ( 11 )   2045 - 2049   2009年11月

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    記述言語:英語   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    Using solid-state reaction method, Zr2WP2O12 powder was synthesized for this study. The optimum heating condition was 1200 degrees C for 4 h. The obtained powder was compacted and sintered. The relative density of the Zr2WP2O12 ceramics with no sintering additive was 60%. That of samples sintered with more than 0.5 mass% MgO was about 97%. The average grain size (D-50), as estimated from the polished surface of a sample sintered at 1200 degrees C for 4 h was about 1 mu m. The obtained ceramics showed a negative thermal expansion coefficient of about -3.4 x 10(-6) degrees C-1. Young's modulus, Poisson's ratio, three-point bending strength, Vickers microhardness, and fracture toughness of the obtained ceramics were, respectively, 74 GPa, 0.25, 113 +/- 13 MPa, 4.4 GPa and 2.3 Mpa m(1/2). (c) 2009 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.materresbull.2009.07.020

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  • Solid acidities of SiO2-TiO2/montmorillonite composites synthesized under different pH conditions

    Yoshikazu Kameshima, Akihiro Yoshizawa, Akira Nakajima, Kiyoshi Okada

    APPLIED CLAY SCIENCE   46 ( 2 )   181 - 184   2009年10月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    SiO2-TiO2/montmorillonite composites were prepared under acidic. neutral and basic conditions and the solid acidity of the resulting composites were determined. All the SiO2/TiO2. ratio of the colloidal particles was set at 10 but the resulting SiO2/TiO2 ratios were significantly richer in TiO2. The XRD patterns of the acidic composite showed expanding and broadening of the (001) reflection by intercalation of colloidal SiO2-TiO2 particles. but the neutral and basic composites showed only broadening of the reflections and no intercalation. The specific surface areas of the acidic. neutral and basic composites (375, 237 and 247 m(2)/g, respectively) were much larger than of montmorillonite (6 m(2)/g). The average pore sizes were about 4.15 and 50 nm. and the amounts of solid acidic sites measured by the NH3-TPD were 178, 95 and 86 mu mol/g for the acidic. neutral and basic composites, respectively. The solid acid amount of the acidic composite was twice that of a commercial catalyst, K-10, (85 mu mol/g) and much higher than the guest phase SiO2-TiO2 gel (16 mu mol/g) or the host phase montmorillonite (6 mu mol/g). The TPD peak temperatures reflect the acid strength, and were similar in all the samples, ranging from 175 degrees to 200 degrees C. (C) 2009 Elsevier B.V. All rights reserved

    DOI: 10.1016/j.clay.2009.08.001

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  • Solid acidities of SiO2-TiO2/montmorillonite composites synthesized under different pH conditions

    Yoshikazu Kameshima, Akihiro Yoshizawa, Akira Nakajima, Kiyoshi Okada

    APPLIED CLAY SCIENCE   46 ( 2 )   181 - 184   2009年10月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    SiO2-TiO2/montmorillonite composites were prepared under acidic. neutral and basic conditions and the solid acidity of the resulting composites were determined. All the SiO2/TiO2. ratio of the colloidal particles was set at 10 but the resulting SiO2/TiO2 ratios were significantly richer in TiO2. The XRD patterns of the acidic composite showed expanding and broadening of the (001) reflection by intercalation of colloidal SiO2-TiO2 particles. but the neutral and basic composites showed only broadening of the reflections and no intercalation. The specific surface areas of the acidic. neutral and basic composites (375, 237 and 247 m(2)/g, respectively) were much larger than of montmorillonite (6 m(2)/g). The average pore sizes were about 4.15 and 50 nm. and the amounts of solid acidic sites measured by the NH3-TPD were 178, 95 and 86 mu mol/g for the acidic. neutral and basic composites, respectively. The solid acid amount of the acidic composite was twice that of a commercial catalyst, K-10, (85 mu mol/g) and much higher than the guest phase SiO2-TiO2 gel (16 mu mol/g) or the host phase montmorillonite (6 mu mol/g). The TPD peak temperatures reflect the acid strength, and were similar in all the samples, ranging from 175 degrees to 200 degrees C. (C) 2009 Elsevier B.V. All rights reserved

    DOI: 10.1016/j.clay.2009.08.001

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  • Preparation of barium titanate nanocube particles by solvothermal method and their characterization

    Satoshi Wada, A. Nozawa, M. Ohno, H. Kakemoto, T. Tsurumi, Y. Kameshima, Y. Ohba

    JOURNAL OF MATERIALS SCIENCE   44 ( 19 )   5161 - 5166   2009年10月

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    記述言語:英語   出版者・発行元:SPRINGER  

    Barium titanate (BaTiO(3)) nanocube particles below 20 nm were prepared by solvothermal method. A selection of organic solvent and inorganic materials of Ba and Ti sources was most important for the preparation of nanocubes. A nucleation and particle growth of BaTiO(3) nanoparticles led to a formation of the BaTiO(3) nanocubes with a size of 10-15 nm at temperatures above 200 A degrees C.

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  • Synthesis of composites of sodium oleate/Mg-Al-ascorbic acid-layered double hydroxides for drug delivery applications

    Yoshikazu Kameshima, Hirokazu Sasaki, Toshihiro Isobe, Akira Nakajima, Kiyoshi Okada

    INTERNATIONAL JOURNAL OF PHARMACEUTICS   381 ( 1 )   34 - 39   2009年10月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Mg-Al-ascorbic acid (ASA)-layered double hydroxides (ASA-LDHs) with Mg/Al = 3 were synthesized by ion-exchange, coprecipitation and reconstruction methods. Composites with sodium oleate (SOA)/ASA-LDH were prepared by an ion-exchange method using various concentrations of SOA solutions. The (0 0 3) basal spacing of the ASA-LDHs changed from 0.76 nm in the CO(3)-LDH to 0.78 and 0.86 nm after intercalation of the ASA ions and these basal spacings are in good agreement with models based on the assumption as mono layers and double layers of ASA ions in the LDH interlayers, respectively. The amounts of ASA in the LDHs prepared by the reconstruction method were higher than those by the ion-exchange and coprecipitation methods. In the preparation of composites of SOA/ASA-LDH, an ion-exchange method was more suitable than a reconstruction method to cause surface sorption of the SOA molecules with maintaining intercalated ASA ions in the LDH interlayers. The acid-resistant properties of the composites of SOA/ASA-LDH were found to be much higher than for the pure ASA-LDH and mixture Of CO(3)-LDH and ASA. The surfaces of the LDH particles in the composites are, thus, mostly covered with sorbed SOA molecules and they are good candidates as drug delivery materials for intestines through the stomach. (C) 2009 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.ijpharm.2009.07.021

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  • Preparation and photocatalytic activity of Keggin-ion tungstate and TiO2 hybrid layer-by-layer film composites

    Sayaka Yanagida, Akira Nakajima, Takayoshi Sasaki, Toshihiro Isobe, Yoshikazu Kameshima, Kiyoshi Okada

    Applied Catalysis A: General   366 ( 1 )   148 - 153   2009年9月

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    記述言語:英語  

    Keggin ions (PW12O403- (PW12), SiW12O404- (SiW12), H2W12O406- (H2W12)) and TiO2 hybrid thin films were prepared using the layer-by-layer method. Their photocatalytic activities were investigated using gaseous 2-propanol decomposition. All films were transparent in the visible wavelength range. For 2-propanol decomposition, H2W12 was the most effective for the combination with TiO2 despite having the smallest TiO2 deposition amount. The photocatalytic activity of the PW12-TiO2 hybrid film was increased 2.3 times by visible light with UV illumination. This increase was less remarkable for hybrid films of other Keggin ions, suggesting that the visible light excitation of reduced PW12 plays an important role in the enhancement of 2-propanol decomposition. © 2009 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.apcata.2009.06.046

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  • Capillary rise properties of porous mullite ceramics prepared by an extrusion method using organic fibers as the pore former

    Kiyoshi Okada, Shuhei Uchiyama, Toshihiro Isobe, Yoshikazu Kameshima, Akira Nakajima, Taisuke Kurata

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   29 ( 12 )   2491 - 2497   2009年9月

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    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    Porous mullite ceramics with unidirectionally oriented pores were prepared by an extrusion method to investigate their capillary rise properties. Rayon fibers 16.5 mu m in diameter and 800 mu m long were used as the pore formers by kneading with alumina powder, kaolin clay, China earthen clay and binder with varying FC(2)O(3) contents of 0, 5 and 7 mass%. The resulting pastes were extruded into cylindrical tubes (outer diameter (OD) 30-50 mm and inner diameter (ID) 20-30 nm), dried at room temperature and fired at 1500 degrees C for 4h. The bulk densities of the resulting porous ceramics ranged from 1.31 to 1.67 g/cm(3), with apparent porosities of 43.2-59.3%. The pore size distributions measured by Hg porosimetry showed a sharp peak at 10.0 mu m in the sample without Fe(2)O(3) and at 15.6 mu m in the samples containing Fe(2)O(3); these pores, which arose from the burnt-out rayon fibers, corresponded to total pore volumes ranging from 0.24 to 0.34 ml/g. SEM showed a microstructure consisting of unidirectionally oriented pores in a porous mullite matrix. Prismatic mullite crystals were well developed on the surfaces of the pore walls owing to the liquid phase formed by the Fe(2)O(3) component added to color the samples. The bending strengths of the tubular samples ranged from 15.6 to 26.3 MPa. The height of capillary rise, measured under controlled relative humidities (RH) of 50, 65 and 85%, was greater in the ceramics containing Fe(2)O(3) than in those without Fe(2)O(3), especially in the thinner samples. The maximum capillary rise reached about 1300 mm, much higher than previously reported. This excellent capillary rise ability is thought to be due to the controlled pore size, pore distribution and pore orientation in these porous mullite ceramics. (C) 2009 Elsevier Ltd. All fights reserved.

    DOI: 10.1016/j.jeurceramsoc.2009.03.012

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  • Effect of the SiO2/TiO2 ratio on the solid acidity of SiO2-TiO2/montmorillonite composites

    Yoshikazu Kameshima, Tomohisa Koike, Toshihiro Isobe, Akira Nakajima, Kiyoshi Okada

    MATERIALS RESEARCH BULLETIN   44 ( 9 )   1906 - 1909   2009年9月

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    記述言語:英語   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    SiO2-TiO2/montmorillonite composites with varying SiO2/TiO2 molar ratios were synthesized and the effect of the SiO2/TiO2 ratio on the solid acidity of the resulting composites was investigated. Four composites with SiO2/TiO2 molar ratios of 0. 0.1, 1 and 10 were synthesized by the reaction of colloidal SiO2-TiO2 particles prepared from alkoxides with sodium-montmorillonite at room temperature. The composites showed slight expansion and broadening of the XRD basal reflection. corresponding to the intercalation of fine colloidal SiO2-TiO2 particles into the montmorillonite sheets and incomplete intercalation to form disordered stacking of exfoliated montmorillonite and colloidal SiO2-TiO2 particles. The colloidal particles crystallized to anatase in the low SiO2/TiO2 composites but remained amorphous in the high SiO2/TiO2 composites. The specific surface areas (S-BET) of the composites measured by N-2 adsorption ranged from 250 to 370 m(2)/g, considerably greater than in montmorillonite (6 m(2)/g). The pore size increased with decreasing SiO2/TiO2 molar ratio of the composites. The NH3-TPD spectra of the composites consisted of overlapping peaks, corresponded to temperatures of about 190 and 290 degrees C. The amounts of solid acid obtained from NH3-TPD were 186-338 mu mol/g in the composites: these values are higher than in the commercial catalyst K10 (85 mu mol/g), which is synthesized by acid-treatment of montmorillonite. The present sample with SiO2/TiO2 = 0.1 showed the highest amount of acid, about four times higher than K10. (C) 2009 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.materresbull.2009.05.005

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  • Preparation of alumina-iron oxide compounds by gel evaporation method and its simultaneous uptake properties for Ni2+, NH4+ and H2PO4-

    Fahmida Gulshan, Yoshikazu Kameshima, Akira Nakajima, Kiyoshi Okada

    JOURNAL OF HAZARDOUS MATERIALS   169 ( 1-3 )   697 - 702   2009年9月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Fe2O3/Al2O3 powders with a range of Fe/Al compositions were prepared by a gel evaporation method to investigate the effect of alumina on the product phases, magnetic properties and simultaneous adsorption of Ni2+ (a model heavy metal cation), NH4+ (a model eutrophication-related cation) and H2PO4- (a model harmful anion). Precursor gels were prepared by dissolving Fe(NO3)(3)center dot 9H(2)O and AI(NO3)(3)center dot 9H(2)O in ethylene glycol, evaporating to dryness, grinding and heating at 300-1000 degrees C for 5 h. The crystalline products were gamma-Fe2O3 (maghemite), formed at 300-600 degrees C, or alpha-Fe2O3 (hematite) and AlFeO3, formed >600 degrees C. The temperatures of the phase change from gamma-Fe2O3 to alpha-Fe2O3 increased with increasing alumina additions. The resulting lattice parameters suggest that Al3+ is incorporated into these phases up to about 15 mol.% at 300 degrees C, falling to 11 mol.% in the gamma-Fe2O3 formed at 600 degrees C. The alpha-Fe2O3 formed at 700 degrees C contained 6 mol.% Al, increasing to 14 mol.% at 1000 degrees C. The magnetic properties of the samples were measured using a vibrating sample magnetometer. The saturation magnetization values of the gamma-Fe2O3-containing samples increased with the addition of alumina to a maximum value of 61 emu/g in the sample containing 95 mol.% Fe2O3 heated at 400 degrees C. The simultaneous adsorption of Ni2+. NH4+ and H2PO4- from water was investigated by a batch method. The highest adsorption values were found for the sample containing 80 mol.% Fe2O3 heated at 600 degrees C, which contained both gamma-Fe2O3 and alpha-Fe2O3. It was therefore concluded that the addition of alumina to iron oxide affects the crystalline phases and phase changes, and enhances the simultaneous cation and anion uptake ability of the materials. (C) 2009 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jhazmat.2009.04.009

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  • Preparation and properties of Cu-grafted transparent TiO2-nanosheet thin films

    Akira Nakajima, Yoshinori Akiyama, Sayaka Yanagida, Tomohisa Koike, Toshihiro Isobe, Yoshikazu Kameshima, Kiyoshi Okada

    MATERIALS LETTERS   63 ( 20 )   1699 - 1701   2009年8月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Transparent TiO2 nanosheet thin films were prepared using layer-by-layer method with poly(diallyidimethylammonium chloride) as a counter polymer. The possibility of photocatalysis by the light in the long wavelength range was examined by grafting Cu on the film. Photocatalytic decomposition activity for gaseous 2-propanol under UV illumination without light for electron excitation of TiO2 nanosheet was increased by Cu grafting. suggesting that the interfacial charge transfer mechanism is effective also for nanosheet films. (C) 2009 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.matlet.2009.05.016

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  • Measurement of non-DLVO force on a silicon substrate coated with ammonium poly(acrylic acid) using scanning probe microscopy

    Toshihiro Isobe, Yosuke Nakano, Yoshikazu Kameshima, Akira Nakajima, Kiyoshi Okada

    APPLIED SURFACE SCIENCE   255 ( 20 )   8710 - 8713   2009年7月

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    記述言語:英語   掲載種別:速報,短報,研究ノート等(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    The repulsive force originating from steric hindrance of polymers in aqueous solvent was investigated using scanning probe microscopy (SPM). The contact angle (CA) of ammonium poly(acrylic acid) (PAA) solution on the Si surface was measured to estimate the state of the Si substrate. Results of CA measurement show that the Si surface was fully covered with PAA at 0.1 mass% in aqueous solution. The interaction force between the Si tip and the wafer was estimated using the SPM force curve mode. The force curve measured in the ion-exchanged purified water showed the typical relation predicted by Derjaguin-Landau-Verway-Overbeek (DLVO) theory. However, the force curve shape in the 0.1 mass% PAA solution was significantly different. Only a repulsive force was observed at less than about 4 nm of separation distance between the Si wafer and cantilever tip. This distance originated from the steric repulsions of PAA adsorbed onto the Si wafer and cantilever tip. Crown Copyright (C) 2009 Published by Elsevier B. V. All rights reserved.

    DOI: 10.1016/j.apsusc.2009.06.050

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  • Water retention properties of porous geopolymers for use in cooling applications

    Kiyoshi Okada, Asami Ooyama, Toshihiro Isobe, Yoshikazu Kameshima, Akira Nakajima, Kenneth J. D. MacKenzie

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   29 ( 10 )   1917 - 1923   2009年7月

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    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    A series of geopolymers were prepared with varying ratios of sodium silicate, metakaolinite, NaOH and H(2)O and their porous properties, water retention and mechanical properties were determined, to develop materials for counteracting heat island effects. Samples were prepared with the molar ratios SiO(2):Al(2)O(3):Na(2)O:H(2)O of 3.66:1:x:y, where x = 0.92-1.08 and y = 14.2-19.5. The porous and mechanical properties of the geopolymers showed a good correlation with the H(2)O/Al(2)O(3) ratio (y); an increase in y produced an increase in the pore volume (from 0.26 to 0.46 ml/g), the pore size (from 15 to 390 nm) and the water absorption (from 27.2 to 51.1%). The same increase in y decreased the bulk density (from 1.29 to 0.99 g/cm(3)), the bending strength (from 14.2 to <5 MPa) and the water retention. Thus, the H(2)O/Al(2)O(3) ratio is the most important factor for controlling the porous properties of these materials, since geopolymers with higher H(2)O/Al(2)O(3) ratios are more porous and have higher water absorption rates, making them suitable as materials for surface cooling by water evaporation. Geopolymers with lower H(2)O/Al(2)O(3) ratios are more suitable for water retention applications, and have the advantage of higher mechanical strength. (C) 2008 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.jeurceramsoc.2008.11.006

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  • Preparation of solid acid carbon coating on the surface of TiO2 by photo-CVD of gaseous aromatic hydrocarbons

    Akira Nakajima, Katsuhiro Horie, Michikazu Hara, Masaaki Kitano, Toshihiro Isobe, Yoshikazu Kameshima, Kiyoshi Okada

    CATALYSIS COMMUNICATIONS   10 ( 13 )   1670 - 1673   2009年7月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Properties of a solid acid carbon coating prepared on TiO2 powder surface using photochemical vapor deposition (photo-CVD) were evaluated. The TiO2 powder surface became brown during UV illumination under a flowing xylene and xylene sulfonic acid mixture. Observation by TEM revealed an amorphous carbon coating on the TiO2 powder. Sulfonate groups were identified on the coating using FT-IR. A chart of NH3-TPD measurements showed two peaks: that at high temperature was attributed to the coating's strong acid. The carbon coating's acidity was equivalent to that of the solid superacid carbon powder and the carbon-coated TiO2 decomposed cellulose. (C) 2009 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.catcom.2009.05.006

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  • Droplet Size Dependence of Line Tension for an Ionic Liquid on a Smooth Silane Coating

    Tsutomu Furuta, Akira Nakajima, Munetoshi Sakai, Toshihiro Isobe, Yoshikazu Kameshima, Kiyoshi Okada

    CHEMISTRY LETTERS   38 ( 6 )   580 - 581   2009年6月

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    記述言語:英語   出版者・発行元:CHEMICAL SOC JAPAN  

    Line tension was measured for microliter-scale and subnanoliter-scale droplets of an ionic liquid on a highly smooth and homogeneous fluoroalkylsilane coating. Values for microliter-scale droplets were two orders larger than those for subnanoliter-scale droplets despite their identical combinations of solid surfaces and liquid. Scale factors related to this measurement and hydrostatic pressure from the liquid play an important role in the discrepancy.

    DOI: 10.1246/cl.2009.580

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  • Preparation and properties of TiO2/montmorillonite composites

    Yoshikazu Kameshima, Yoshihiro Tamura, Akira Nakajima, Kiyoshi Okada

    APPLIED CLAY SCIENCE   45 ( 1-2 )   20 - 23   2009年6月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    TiO2/montmorillonite composites were prepared by reaction of montmorillonite with a TiO2 Sol formed by hydrolyzing titanium iso-propoxide, at 50-80 degrees C. The composites showed expanding and broadening of the basal reflections of montmorillonite indicating a partial intercalation of the smaller colloidal TiO2 particles and increased disorder. The reaction temperature affected largely the amount of TiO2 hydrolyzed and the resulting pore sizes. Both properties increased with increasing reaction temperature: the TiO2 content from 24.2 to 46.6 mass% and the average pore size from 2 to 20 nm. The colloidal TiO2 particles consisted of anatase up to 1000 degrees C without transforming into rutile. The growth of the TiO2 particles was suppressed by the montmorillonite particles. Adsorption of methylene blue (MB) was higher in the composite prepared at 80 degrees C than in that at 50 degrees C because of the larger pore size. Photocatalytic decomposition of 1,4-dioxane by the composites was higher than for pure anatase due to the synergy effect of adsorption for 1,4-dioxane and photodecomposed intermediates by montmorillonite and its photodecomposition by TiO2. (C) 2009 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.clay.2009.03.005

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  • Evaporation and Sliding of Water Droplets on Fluoroalkylsilane Coatings with Nanoscale Roughness

    Tsutomu Furuta, Akira Nakajima, Munetoshi Sakai, Toshihiro Isobe, Yoshikazu Kameshima, Kiyoshi Okada

    LANGMUIR   25 ( 10 )   5417 - 5420   2009年5月

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    記述言語:英語   出版者・発行元:AMER CHEMICAL SOC  

    Evaporation and sliding behaviors of water droplets were investigated on smooth and rough fluoroalkylsilane coatings. The rough coating possesses nanoscale roughness and chemical heterogeneity on its surface. Evaporation behaviors for these two coatings differed when nanoliter-scale droplets were used, although they were nearly identical for rnicroliter-scale droplets. The droplets on the smooth coating exhibit greater sliding acceleration and a larger slipping velocity ratio than those on the rough coating. Both the evaporation behavior of nanoliter-scale droplets and sliding velocity of microliter-scale droplets were affected by nanoscale surface heterogeneity. They are indicators for highly homogeneous smooth silane coatings.

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  • Preparation and abrasion resistance of transparent super-hydrophobic coating by combining crater-like silica films with acicular boehmite powder

    Tomoki Yanagisawa, Akira Nakajima, Munetoshi Sakai, Yoshikazu Kameshima, Kiyoshi Okada

    MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS   161 ( 1-3 )   36 - 39   2009年4月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    A super-hydrophobic coating was prepared by combining a rigid base film with crater-like hemispherical holes and acicular nanoparticles. The acicular boehmite powder provides a high contact angle on the film surface. The rigid base film with crater-like hemispherical holes inhibits the rapid decrease of contact angle by surface rubbing. The combination of different roughness is an effective method for improving the abrasion resistance of super-hydrophobic films. (C) 2008 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.mseb.2008.11.016

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  • Dependence of photoinduced surface friction force variation on UV intensity and atmosphere in polycrystalline TiO2 thin films

    Naoki Arimitsu, Akira Nakajima, Toshiya Watanabe, Yoshikazu Kameshima, Kiyoshi Okada

    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY   203 ( 2-3 )   155 - 160   2009年4月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE SA  

    Anatase polycrystalline thin films and a plasma crystallization process were used to investigate the dependence of the photoinduced friction force variation for a TiO2 Surface on the UV intensity and atmosphere. Photoinduced friction force variation for UV illumination time was divisible into two stages, decreasing and increasing, where the switching time between these two stages and the degree of variation depended oil the UV intensity and atmosphere. The decreasing stage was attributable to the photocaralytic decomposition of organic compound adsorbed onto the Surface, whereas the increasing stage was attributed to the capillary effect or an increase in the adsorbed water layer. Results demonstrated that UV intensity and atmosphere controlled the friction force. (C) 2009 Elsevier B.V. All lights reserved.

    DOI: 10.1016/j.jphotochem.2009.01.009

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  • Low temperature preparation and machinability of porous ceramics from talc and foamed glass particles

    Kiyoshi Okada, Fumihiko Ikawa, Toshihiro Isobe, Yoshikazu Kameshima, Akira Nakajima

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   29 ( 6 )   1047 - 1052   2009年4月

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    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    Porous ceramics were prepared by firing mixtures of talc (Mg(3)Si(4)O(10)(OH)(2)) and foamed glass particles (ceramic balloons, CB) with and without LiCl as a sintering acid. The mixing ratios of the starting materials were talc:CB = 7:3, 8:2, 9:1 and 10:0, with additions of LiCl of 0, 2 and 5 mass%. The mixtures were formed into pellets and fired at 600-1000 degrees C. The pellets without LiCl showed very poor strength even when fired at 1000 degrees C but those containing LiCl were much stronger, even when fired at only 600 degrees C. The crystalline phases in these samples changed to enstatite (MgSiO(3)) at >= 700 degrees C by decomposition of the talc under the fluxing action of the LiCl. The resulting samples were machinable and easily cut and drilled. The cutting rate decreased with increasing bending strength, for example, from 105 mm(2)/s and 6.3 MPa to 50 mm(2)/s and 16.3 MPa, respectively. The drilling rate of the present sample was found to be only slightly less than Teflon (polytetrafluoroethylene, PTFE) but much faster than graphite, glass ceramics, etc. (C) 2008 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.jeurceramsoc.2008.07.055

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  • Bioactivity and mechanical properties of CaSiO3/high-density polyethylene (HDPE) composites prepared by a new surface loading method of CaSiO3 powder

    Kiyoshi Okada, Miho Tanuma, Yoshikazu Kameshima, Akira Nakajima, Shigeo Asai, Masao Sumita

    MATERIALS RESEARCH BULLETIN   44 ( 2 )   298 - 305   2009年2月

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    記述言語:英語   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    CaSiO3/high-density polyethylene (HDPE) composites with flexibility and biocompatibility were prepared by a new surface loading method. CaSiO3 powder was synthesized by coprecipitation method with heating at 1300 degrees C for 2 h. The obtained alpha-CaSiO3 powder was sieved to 45-75 mu m (sample M) and 75-150 mu m (sample C). Fine powder sample (sample F) was prepared by grinding the powder being the average particle size of 2.9 mu m. These powders were sprinkled on the melted HDPE sheets heated at 160, 180 and 200 degrees C. The amounts of sprinkled powder were only <0.1 vol.% but the ratios of surface coverage area were >50% in all the samples. Apatite formation in simulated body fluid (SBF) was observed by soaking for 5 days in sample F while within 1 day in samples M and C. The sample M retained flexible properties of HDPE together with excellent biocompatible properties. (C) 2008 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.materresbull.2008.06.011

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  • Preparation and properties of titania-Cs2.5H0.5PW12O40 hybrid films

    Akira Nakajima, Shunsuke Matsui, Sayaka Yanagida, Yoshikazu Kameshima, Kiyoshi Okada

    SURFACE & COATINGS TECHNOLOGY   203 ( 9 )   1133 - 1137   2009年1月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE SA  

    Using continuous coating with Si-alkoxide as a binder, Cs2.5H0.5PW12O40 (Cs2.5) powder was prepared and immobilized onto a Pyrex glass plate. The Cs2.5 coating possessed an acid site on the film surface. Translucent TiO2-Cs2.5 hybrid films were prepared by laminating TiO2 films with holes on the Cs2.5 coating using phase-separation of alkoxide. Photocatalytic decomposition of 1,4-dioxane in water revealed that the holes serve as adsorption fields for ethylene glycol diformate, an intermediate with poor affinity to TiO2. The TiO2-Cs2.5 hybrid films produced by this process are candidates for purification of water containing several chemicals with a slow decomposition rate in photocatalysis. (C) 2008 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.surfcoat.2008.10.010

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  • Effect of Surface Structure on the Sustainability of an Air Layer on Superhydrophobic Coatings in a Water-Ethanol Mixture

    Munetoshi Sakai, Tomoki Yanagisawa, Akira Nakajima, Yoshikazu Kameshima, Kiyoshi Okada

    LANGMUIR   25 ( 1 )   13 - 16   2009年1月

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    記述言語:英語   出版者・発行元:AMER CHEMICAL SOC  

    Using a laser beam and its reflection, we evaluated surface air layers on two superhydrophobic coatings with different roughnesses (R(a) = 1900 and 74 nm) in a water-ethanol mixture. The reflected laser intensity decreased by increasing the ethanol concentration for the superhydrophobic coating with large roughness because of increased scattering by the surface structure of the solid. However, it was almost constant and slightly increased for the coating with small roughness, probably because the liquid-air interface becomes flatter as the liquid intrudes into the surface structure. Results demonstrated that the difference in surface structure provides different sustainability of the surface air layer.

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  • New hybrid nanostructures based on oxacillin-hydrotalcite-like anionic clays and their textural properties

    Gabriela Carja, Yoshizaku Kameshima, Gabriela Ciobanu, Horia Chiriac, Kiyoshi Okada

    MICRON   40 ( 1 )   147 - 150   2009年1月

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    記述言語:英語   掲載種別:書評論文,書評,文献紹介等   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    New hybrid nanostructures based on inorganic matrices of hydrotalcite-like anionic clays (HT) incorporated with oxacillin are obtained by using calcinations-restructure method. XRD and TEM analyses are used to study the structural and textural characteristics of the clay containing hybrids. When nanoparticles of iron oxides are loaded on the layered anionic clay matrix a more effective delivery system of the drug is obtained. The results can be used to reduce the toxic side effects of oxacillin (e.g. upset stomach, diarrhea, cholestastic hepatitis), its aggregation process in aqueous solutions and also can open new perspectives for targeted the drug delivery. (C) 2007 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.micron.2007.12.001

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  • Preparation and electrochemical property of manganese oxide/carbon composites

    Y. Kameshima, H. Wagata, A. Nakajima, K. Okada

    Journal of Physics: Conference Series   191   12015   2009年

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    記述言語:英語   出版者・発行元:Institute of Physics Publishing  

    A novel electro-chemical capacitor was tried to synthesis by assemble carbon powder with manganese oxide using an ultra-sonication in KMnO4 solution. (ultrasonic sample). A reference sample was prepared by same condition except for radiation of ultra-sonication (settle sample). Both ultrasonic sample and settle sample show the composite of manganese oxide and carbon. Additionally, layered manganese oxide phase was observed in the ultrasonic samples. Surface atomic ratio of Mn/C decreased corresponding with increasing of used solution volume from 25 ml to 250 ml. The composite prepared using 100ml solution was greatly affected by the ultra-sonication. On the other hand, the amount of manganese on the surface has increased with the increasing of the irradiation of energy among the ultrasonic sample. The amount of manganese deposition was almost saturated with 100 mW/cm3. Cyclic voltammetry curves of the obtained composites were influenced by scanning speed. The ultrasonic sample shows higher electrical capacitance than the settle sample in various conditions. © 2009 IOP Publishing Ltd.

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  • Preparation of Pt particles dispersing nanocomposites by thermal treatment of tetrachloroplatinate/layered double hydroxide

    Y. Kameshima, A. Nakajima, K. Okada, T. Yano

    J. Ceram. Soc. Jpn.   117 ( 1371 )   1229 - 1232   2009年

  • Mass Dependence of Slipping/Rolling Ratio in Sliding Acceleration of Water Droplets on a Smooth Fluoroalkylsilane Coating

    S. Suzuki, A. Nakajima, Y. Sakurada, M. Sakai, N. Yoshida, A. Hashimoto, Y. Kameshima, K. Okada

    J. Jpn. Soc. Colour Mater.   82 ( 1 )   3 - 8   2009年

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  • Intercalation Behavior of Various Fatty Acids into Mg-Al-Layered Double Hydroxide

    Y. Kameshima, H. Sasaki, T. Isobe, A. Nakajima, K. Okada

    Clay Sci.   14 ( 2 )   87 - 94   2009年

  • Photocatalytic destruction of 1,4-dioxane in aqueous system by surface-roughened tio2 coating on stainless mesh

    Sayaka Yanagida, Akira Nakajima, Yoshikazu Kameshima, Kiyoshi Okada

    Key Engineering Materials   412   137 - 141   2009年

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    記述言語:英語  

    This study investigated the effect of surface roughness on a coating of TiO2 submicron powders that had been applied on a stainless steel mesh using electrophoretic deposition (EPD). Roughness was provided to the surface of EPD coating using UV pre-illumination to the suspension prepared by isopropyl alcohol and commercial TiO2 powder. The Ra value was increased around 20% by this treatment. The rough coating provided a higher photocatalytic decomposition rate of 1,4-dioxane in water than a smooth coating obtained from the suspension without UV pre-illumination. That increase is attributable to the increase of the reaction field on the coating surface.

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  • Photocatalytic destruction of 1,4-dioxane in aqueous system by surface-roughened TiO(2) coating on stainless mesh

    Sayaka Yanagida, Akira Nakajima, Yoshikazu Kameshima, Kiyoshi Okada

    ELECTROPHORETIC DEPOSITION: FUNDAMENTALS AND APPLICATIONS III   412   137 - 141   2009年

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    記述言語:英語   出版者・発行元:TRANS TECH PUBLICATIONS LTD  

    This study investigated the effect of surface roughness on a coating of TiO(2) submicron powders that had been applied on a stainless steel mesh using electrophoretic deposition (EPD). Roughness was provided to the surface of EPD coating using UV pre-illumination to the suspension prepared by isopropyl alcohol and commercial TiO(2) powder. The R(a) value was increased around 20% by this treatment. The rough coating provided a higher photocatalytic decomposition rate of 1,4-dioxane in water than a smooth coating obtained from the suspension without UV pre-illumination. That increase is attributable to the increase of the reaction field on the coating surface.

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  • Photocatalytic destruction of 1,4-dioxane in aqueous system by surface-roughened TiO(2) coating on stainless mesh

    Sayaka Yanagida, Akira Nakajima, Yoshikazu Kameshima, Kiyoshi Okada

    ELECTROPHORETIC DEPOSITION: FUNDAMENTALS AND APPLICATIONS III   412   137 - 141   2009年

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    記述言語:英語   出版者・発行元:TRANS TECH PUBLICATIONS LTD  

    This study investigated the effect of surface roughness on a coating of TiO(2) submicron powders that had been applied on a stainless steel mesh using electrophoretic deposition (EPD). Roughness was provided to the surface of EPD coating using UV pre-illumination to the suspension prepared by isopropyl alcohol and commercial TiO(2) powder. The R(a) value was increased around 20% by this treatment. The rough coating provided a higher photocatalytic decomposition rate of 1,4-dioxane in water than a smooth coating obtained from the suspension without UV pre-illumination. That increase is attributable to the increase of the reaction field on the coating surface.

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  • Preparation and electrochemical property of manganese oxide/carbon composites

    Y. Kameshima, H. Wagata, A. Nakajima, K. Okada

    Journal of Physics: Conference Series   191   12015   2009年

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    記述言語:英語   出版者・発行元:Institute of Physics Publishing  

    A novel electro-chemical capacitor was tried to synthesis by assemble carbon powder with manganese oxide using an ultra-sonication in KMnO4 solution. (ultrasonic sample). A reference sample was prepared by same condition except for radiation of ultra-sonication (settle sample). Both ultrasonic sample and settle sample show the composite of manganese oxide and carbon. Additionally, layered manganese oxide phase was observed in the ultrasonic samples. Surface atomic ratio of Mn/C decreased corresponding with increasing of used solution volume from 25 ml to 250 ml. The composite prepared using 100ml solution was greatly affected by the ultra-sonication. On the other hand, the amount of manganese on the surface has increased with the increasing of the irradiation of energy among the ultrasonic sample. The amount of manganese deposition was almost saturated with 100 mW/cm3. Cyclic voltammetry curves of the obtained composites were influenced by scanning speed. The ultrasonic sample shows higher electrical capacitance than the settle sample in various conditions. © 2009 IOP Publishing Ltd.

    DOI: 10.1088/1742-6596/191/1/012015

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  • Preparation and Abrasion Resistance of Transparent Super-hydrophobic Coating by Combining Crater-like Silica Films with Acicular Boehmite Powder

    Tomoki YANAGISAWA, Akira NAKAJIMA, Munetoshi SAKAI, Yoshikazu KAMESHIMA, Kiyoshi OKADA

    Catal. Commun.   10   1670 - 1673   2009年

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  • Rolling and slipping motion of a water droplet sandwiched between two parallel plates coated with fluoroalkylsilanes

    Shunsuke Suzuki, Akira Nakajima, Munetoshi Sakai, Ayako Hashimoto, Naoya Yoshida, Yoshikazu Kameshima, Kiyoshi Okada

    APPLIED SURFACE SCIENCE   255 ( 5 )   3414 - 3420   2008年12月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Si plates were treated using two fluoroalkylsilanes (FAS17 and FAS3), and the internal fluidity of a water droplet sliding between two parallel plates on a slope was observed directly using particle image velocimetry (PIV) method with a high-speed camera system. The interfacial caterpillar-like rotation flows with slip motion at the solid-liquid interface were related to the combination of top and bottom wettabilities. The water droplets accelerated by a rolling and slipping motion on FAS17 coatings; the acceleration was dominated by a rolling motion on FAS3 coatings. A droplet's shape, solid-liquid molecular interaction, and the gravitic force will be important factors determining the sliding mode on a solid surface. (C) 2008 Elsevier B. V. All rights reserved.

    DOI: 10.1016/j.apsusc.2008.09.059

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  • Size dependence of THz region dielectric properties for barium titanate fine particles

    Satoshi Wada, Hiroaki Yasuno, Takuya Hoshina, Hirofumi Kakemoto, Yoshikazu Kameshima, Takaaki Tsurumi

    JOURNAL OF ELECTROCERAMICS   21 ( 1-4 )   198 - 201   2008年12月

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    記述言語:英語   出版者・発行元:SPRINGER  

    Barium titanate (BaTiO(3)) crystallites with various particle sizes froth 22 to 500 nm were prepared by the two-step thermal decomposition method of barium titanyl oxalate. Various characterizations revealed that these particles were impurity-free, defect-free, dense BaTiO(3) particles. The powder dielectric measurement clarified that the dielectric constant of BaTiO(3) particles with a size of around 58 nm exhibited a maximum of over 15,000. To explain this size dependence, the THz region dielectric properties of BaTiO(3) tine particles, especially Slater mode frequency, were measured using the far infrared (FIR) reflection method. As the result, the lowest Slater mode frequency was obtained at 58 nm. This tendency was completely consistent with particle size dependence of the dielectric constant.

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  • Nanoparticles of iron and vanadium oxides supported on iron substituted LDHs: Synthesis, textural characterization and their catalytic behavior in ethylbenzene dehydrogenation

    Gabriela Carja, Yoshikazu Kameshima, Kiyoshi Okada

    MICROPOROUS AND MESOPOROUS MATERIALS   115 ( 3 )   541 - 547   2008年11月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Nanostructured catalysts derived from nanoparticles of iron or vanadium oxides supported on the matrices of iron substituted hydrotalcite-like anionic clays (layered double hydroxides, LDHs) have been obtained and tested in the process of ethylbenzene dehydrogenation to styrene. A simple synthesis method based on the LDHs "memory effect" has been used to prepare the new oxides-anionic clay structures. TEM analysis shows that on the typical FeLDH particles (average size equal to 75 nm) smaller nanoparticles are supported; their average size is equal to 7 and I I nm for Fe/FeLDH and V/FeLDH respectively. XPS analysis indicates the presence of Fe2O3 and V2O3 on the surface of the supported LDHs. N-2 adsorption at 77 K reveals that the supported anionic clays have less accentuated mesoporous properties in comparison to the parent FeLDH matrix. The catalytic behavior of the samples is a function of the nature of the supported nanoparticles. (c) 2008 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.micromeso.2008.02.032

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  • LDH-maleic anhydride copolymers as new hybrid materials and their textural organisation

    Gabriela Carja, Gabrielle Charlote Chitanu, Yoshikazu Kameshima, Horia Chiriac, Kiyoshi Okada

    APPLIED CLAY SCIENCE   41 ( 3-4 )   107 - 112   2008年10月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    New hybrid materials based on maleic anhydride-vinyl acetate copolymers incorporated within a LDH network (Mg/Al=2/1) were obtained by using either the coprecipitation method or the reconstruction method. XRD, FTIR and DTA analyses were used for obtaining information about the structural features of the new synthesized hybrid structure. The textural organisation at micro-nanoscale of the samples was studied by using SEM and TEM microscopy techniques. The inorganic matrix and the polymer both contribute to establish the specific micromorphology of the studied samples: well defined microsheets were stacked one of top of the other. The thickness and shape of the microsheets and their textural disorder were influenced by the synthesis procedure. The agglomerated particles preserved the typical platelet morphology of the LDH though they partially entrapped the fibrous particles of the polymer. These results can open new perspectives in designing new hybrid materials with specific textural organisation at micro- nanoscale. (C) 2007 Elsevier B.V All rights reserved.

    DOI: 10.1016/j.clay.2007.10.002

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  • Preparation of barium titanate nanoparticle sphere arrays and their dielectric properties

    Satoshi Wada, Aki Yazawa, Takuya Hoshina, Yoshikazu Kameshima, Hirofumi Kakemoto, Takaaki Tsurumi, Yoshihiro Kuroiwa

    IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL   55 ( 9 )   1895 - 1899   2008年9月

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    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    Barium titanate (BaTiO3) nanoparticles from 27 to 192 nm were prepared by the 2-step thermal decomposition method from barium titanyl oxalate nanoparticles. These particles were dispersed well into 1-propanol, and dense BaTiO3 nanoparticle sphere arrays without stress-field were prepared by the meniscus method. Temperature dependence of dielectric properties was successfully measured using these dense nanoparticle sphere arrays, and size effect on dielectric properties was discussed.

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  • Effect of the crystallinity of kaolinite precursors on the properties of mesoporous silicas

    Myoshi Okada, Hisako Yoshizaki, Yoshikazu Kameshima, Akira Nakajima

    APPLIED CLAY SCIENCE   41 ( 1-2 )   10 - 16   2008年9月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Mesoporous silicas (MesoPSs) were hydrothermally synthesized from calcined and selectively acid-leached kaolinites with a range of crystallinity, using cetyltrimethyl ammonium bromide (CTABr), to investigate the effect of the kaolinite crystallinity on the porous properties of the resulting MesoPSs. Four kaolinites were used, with Hinckley indices ranging from 0.51 to 1.20 and (001) crystallite sizes ranging from 20 to 37 nm. After calcination at 600 degrees C for 24 h they were selectively leached with 2.5 M H(2)SO(4) at 90 degrees C for 2 h to prepare microporous silica (MicroPSs). The Si/Al ratios of these MicroPSs varied from 21 to 82 and their specific surface areas (S(BET)) ranged from 169 to 370 m(2)/g, these parameters tending to increase with decreasing Hinckley index of the kaolinite. MesoPSs were synthesized by reacting the resulting MicroPSs with CTABr in NaOH solution under hydrothermal conditions. The MicroPS was mixed with CTABr, NaOH and water in the molar ratio (MicroPS):CTABr:NaOH:H(2)O = 1:0.1:0.3:150. The synthesis was carried out by stirring the suspension at room temperature for 24 h, aging for 24 h, hydrothermal treatment at 110 degrees C for 24 h and calcination at 560 degrees C for 6 h to remove the surfactants. The S(BET) values of the resulting MesoPSs ranged from 932 to 1240 m(2)/g, correlating with the S(BET) values of the precursor MicroPS and the crystallinity of the kaolinite starting materials. (C) 2007 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.clay.2007.09.009

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  • Utilization of steel-making slag for the uptake of ammonium and phosphate ions from aqueous solution

    Vinay Kumar Jha, Yoshikazu Kameshima, Akira Nakajima, Kiyoshi Okada

    JOURNAL OF HAZARDOUS MATERIALS   156 ( 1-3 )   156 - 162   2008年8月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Steel-making slag, a waste by-product of the Steel Industry, constitutes a major disposal problem. In the present study, excellent adsorbent materials for reducing eutrophication in wastewaters have been prepared from this slag. Heated samples of acid-treated slag and mixtures of slag with kaolinite and Al(OH)(3) were examined to determine their uptake capacities for NH4+ and PO43- from aqueous solutions. In general, the equilibrium pH of the solution increased in comparison to initial pH with the uptake of target ions, the sample activated slag-Al(OH)(3) showing the smallest change. The highest PO43- uptake capacity was obtained with the slag-Al(OH)(3) mixture heated at 900 degrees C whereas the highest uptake of NH4+ was found in the slag-Al(OH)(3) mixture heated at 800 degrees C. The uptake rates for PO43- and NH4+ by the slag-Al(OH)(3) mixture heated at 900 degrees C were 2.91 and 0.65 mu mol/(g min), respectively. It was shown that heating slag composites prior to incorporation into wastewater treatment filters resulted in an increased degree of NH4+ and PO43- uptake. (C) 2007 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jhazmat.2007.12.009

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  • Processing and properties of transparent sulfated TiO(2) thin films using sol-gel method

    Akira Nakajima, Aiko Nakamura, Naoki Arimitsu, Yoshikazu Kameshima, Kiyoshi Okada

    THIN SOLID FILMS   516 ( 18 )   6392 - 6397   2008年7月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE SA  

    For this study, transparent sulfated TiO(2) thin films were prepared from Ti alkoxide. Vacuum ultraviolet illumination in air at 180 degrees C was demonstrated to be an effective pretreatment for reproducible preparation of crack-free sulfated TiO(2) thin films. The film provides a high photoinduced wettability conversion rate and photocatalytic decomposition efficiency on gaseous n-hexane under proper conditions. This result is attributable to the accelerated decomposition of intermediates by a strong inorganic acid on the surface or to the resultant high quantum yield by suppressing the recombination between electrons and holes on the film surface. (c) 2008 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.tsf.2007.12.161

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  • Effect of liquid viscosity on the internal fluidity of a droplet sliding on a fluoroalkylsilane coating

    Yuu Sakurada, Shunsuke Suzuki, Munetoshi Sakai, Akira Nakajima, Yoshikazu Kameshima, Kiyoshi Okada

    CHEMISTRY LETTERS   37 ( 7 )   688 - 689   2008年7月

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    記述言語:英語   出版者・発行元:CHEMICAL SOC JAPAN  

    The effect of liquid viscosity on the internal fluidity of droplets during sliding on an inclined Si surface treated with fluoroalkylsilane (FAS) was investigated for water-glycerin mixture using particle image velocimetry (PIV). Increasing viscosity remarkably decreases the slipping motion on the solid-liquid interface and overall sliding acceleration. It affects the rolling motion, but its degree of influence is smaller than that on slipping. The viscosity had different contributions to slipping and rolling motions of the droplets.

    DOI: 10.1246/cl.2008.688

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  • Processing and photocatalytic properties of transparent 12 tungsto(VI) phosphoric acid - TiO(2) hybrid films

    Sayaka Yanagida, Akira Nakajima, Takayoshi Sasaki, Yoshikazu Kameshima, Kiyoshi Okada

    CHEMISTRY OF MATERIALS   20 ( 11 )   3757 - 3764   2008年6月

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    記述言語:英語   出版者・発行元:AMER CHEMICAL SOC  

    Using the layer-by-layer method, 12 tungsto(VI) phosphoric acid (PW(12)) and TiO(2) hybrid thin films were prepared. In 2-propanol decomposition, two-bilayer thin films (ca. 15 nm) showed more rapid decomposition than control TiO(2) and PW(12) films under both UV and Visible light illumination. Visible light illumination was required for continuous 2-propanol decomposition. Photocatalytic decomposition activity depends on the number of bilayer coatings, the top coating, and the organic compounds for decomposition. On the basis of the wavelength dependence of the hybrid thin films, a reaction scheme for this system was discussed.

    DOI: 10.1021/cm800167x

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  • Effect of atmosphere on photo-induced friction force variation on (001) rutile

    Akira Nakajima, Aya Nakada, Naoki Arimitsu, Yoshikazu Kameshima, Kiyoshi Okada

    MATERIALS LETTERS   62 ( 8-9 )   1319 - 1321   2008年3月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Variations of friction force and surface potential were evaluated using friction force microscopy (FFM) and Kelvin force microscopy (KFM) on (100) and (001) faces of rutile single crystals under UV illumination in three different atmospheres: dry nitrogen, dry air, and ambient air. Friction force and surface roughness for the (100) face did not exhibit remarkable dependence on either UV illumination or on the atmosphere. However, the friction force of the (001) face increased by UV illumination in dry air without roughness variation. The surface potential of the (001) face changed negatively and more remarkably than that of the (100) face by UV illumination. (C) 2007 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.matlet.2007.08.036

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  • Preparation and sorption properties of materials from paper sludge

    M. Hojamberdiev, Y. Kameshima, A. Nakajima, K. Okada, Z. Kadirova

    JOURNAL OF HAZARDOUS MATERIALS   151 ( 2-3 )   710 - 719   2008年3月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Three materials were prepared from paper sludge (PS) using different treatment processes and their sorption abilities for phosphate and methylene blue (MB) were determined. The samples were a powder sample prepared by heating PS in air (sample C), a pellet prepared by grinding, forming and heating PS in air (sample G) and a powder prepared by physical activation of PS in flowing wet nitrogen (sample A). The three samples were heated at 600-900 degrees C for 6h. On heating at 700-800 degrees C, the organic fibers, limestone (CaCO3) kaolinite (Al2Si2O5(OH)(4)) and talc (Mg3Si4O10(OH)(2)) in the original PS were converted to amorphous CaO-Al2O3-SiO2 (CAS) and talc in sample C, while CAS was formed in sample G and activated carbon, CAS and talc was formed in sample A. On heating at 900 degrees C the CAS converted to gehlenite (Ca2Al2SiO7) and anorthite (CaAl2Si2O8). The specific surface areas (SBET) of the three samples achieved maximum values of 23, 37 and 70 m(2)/g upon heating at 700, 600 and 600 degrees C, respectively. The SBET value of the activated sample A was distinctly lower than usually reported for activated carbon. The samples C, G and A achieved maximum phosphate sorption capacities of 2.04, 1.38 and 1.70 mmol/g, calculated from the Langmuir model, upon heating at 700, 700 and 800 C, respectively. The maximum sorption capacity for phosphate in sample C is attributed to the sorption by CAS, namely, adsorption on the alumina component and precipitation as Ca-phosphates. The MB multifunctional sorption capacity of sample A was 0.11 mmol/g. The phosphate and MB sorption rates show better correlation with a pseudo-second order model than with other models. (C) 2007 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jhazmat.2007.06.058

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  • Water-retention properties of porous ceramics prepared from mixtures of allophane and vermiculite for materials to counteract heat island effects

    Kiyoshi Okada, Shunsuke Matsui, Toshihiro Isobe, Yoshikazu Kameshima, Akira Nakajima

    CERAMICS INTERNATIONAL   34 ( 2 )   345 - 350   2008年3月

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    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    Porous ceramics for anti-heat island effect were prepared from mixtures of allophane and vermiculite (VA samples). Allophane and vermiculite which had been ground for 0.5-2 h was mixed in various mass ratios, formed into pellets by uniaxial pressing at 40 MPa, and heated at 600-800 degrees C to form porous ceramics. The large thermal expansion of the vermiculite upon explosive dehydration of interlayer water causes cracking of the pellets with higher vermiculite contents. However, this can be controlled by grinding the vermiculite prior to heating. Grinding the vermiculite for >= 2 It suppresses its expansion, enabling pellet samples with high vermiculite contents to be prepared without cracking. The bulk densities of samples prepared at 800 degrees C from vermiculite ground for 2 h decrease from 1.72 to 0.94 with increasing allophane content. The pore size distribution in these samples shows a distinct peak at about 1 mu m irrespective of the mixing ratio. The number of smaller pores (50 nm) increases with increasing allophane content while the number of larger pores (20-40 mu m) increases with increasing vermiculite content. The compressive strengths of the samples range from I to 3 MPa except for samples containing a high proportion of vermiculite ground for I h. The water absorption (W-a) of the samples increases from 37 to 63% with increasing allophane content. This absorption rate is fast enough to absorb >90% of the W-a within 1 min for samples of 10 mm phi x 5 mm(3) size. By contrast, the release of the absorbed water is very slow, with 50% of the W-a retained for >= 30 h in the VA samples at a relative humidity of 55% at 20 degrees C this is slower than in pure allophane and much slower than in a reference sample of foamed glass (about 4 h). All these properties make the VA samples useful as water-retaining materials to combat "heat island" effects. (c) 2006 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

    DOI: 10.1016/j.ceramint.2006.10.006

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  • Preparation and simultaneous ion uptake properties of CaO-Fe2O3-SiO2 compounds

    Atsushi Kobayashi, Fahmida Gulshan, Yoshikazu Kameshima, Akira Nnakajima, Kiyoshi Okada

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   116 ( 1350 )   187 - 191   2008年2月

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    記述言語:英語   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    CaO-Fe2O3-SiO2 (CFS) compounds were prepared from mixtures of Ca(OH)(2), FeOOH and SiO2 and their simultaneous uptake properties for cations and anions were investigated. The starting powders were mixed in various ratios using a planetary ball mill and heated at various temperatures in air and flowing N-2 atmospheres. Amorphous compounds were formed by heating up to <600 degrees C while hematite (alpha-Fe2O3) was crystallized at >= 600 degrees C and calcium silicates and/or calcium iron silicates at >= 800 degrees C. Simultaneous ion uptake experiments were carried out by a batch method using solutions containing same concentrations of Ni2+, NH4+ and H2PO4-. The samples heated at 600 degrees C showed the highest ion uptake ability. The uptake abilities were higher for Ni2+ and H2PO4- than for NH4+ and increased with increasing CaO content in the CFSs. The uptake abilities for three ions enhanced by heating the samples in flowing N-2. The simultaneous uptake mechanisms are thought to be similar to those observed in the CAS compounds, i.e. ligand change (Ca2+ -> Ni2+), compound precipitation and adsorption. The CFS compounds have the following advantages compared with CaO-Al2O3-SiO2 (CAS); (1) higher uptake ability for phosphate ions (a model for harmful oxyanions) and (2) easy separation of a contaminated sorbent from the solution after uptake using a magnet.

    DOI: 10.2109/jcersj2.116.187

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  • Voltage swing interval effects on photocatalytic decomposition of 1,4-dioxane in aqueous media using TiO2-coated stainless mesh

    Sayaka Yanagida, Akira Nakajima, Yoshikazu Kameshima, Kiyoshi Okada

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN   116 ( 1350 )   181 - 186   2008年2月

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    記述言語:英語   出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI  

    This study investigates the effects of a voltage swing interval on 1,4-dioxane decomposition in aqueous media. The concentration of 1,4-dioxane decreases with the decreasing voltage swing interval, but the change is small. In contrast, the concentration of EGDF increases with the decreasing interval. Its difference is much greater than that of 1,4-dioxane. These results suggest that the diffusion constant of EGDF in a pore structure differs from that of 1,4-dioxane and that the response to the voltage swing interval depends on the chemical species. For effective water purification using this system, proper material design and optimization of operation conditions are necessary.

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  • Sliding behavior of water droplets on line-patterned hydrophobic surfaces

    Shunsuke Suzuki, Akira Nakajima, Kouichi Tanaka, Munetoshi Sakai, Ayako Hashimoto, Naoya Yoshida, Yoshikazu Kameshima, Kiyoshi Okada

    APPLIED SURFACE SCIENCE   254 ( 6 )   1797 - 1805   2008年1月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    We prepared line-patterned hydrophobic surfaces using fluoroalkylsilane (FAS) and octadecyltrimethoxysilane (ODS) then investigated the effect of line direction on sliding behavior of water droplets by direct observation of the actual droplet motion during sliding. Water droplets slide down with a periodic large deformation of the contact line and sliding velocity fluctuation that occurred when they crossed over the 500-mu m ODS line regions in FAS regions on a Si surface tilted at 35 degrees. These behaviors are less marked for motion on a 100-mu m line surface, or on lines oriented parallel to the slope direction. Smaller droplets slide down with greater displacement in the line direction on 500-mu m line patterning when the lines were rotated at 13 degrees in-plane for the slope direction. This sliding behavior depended on the droplet size and rotation angle, and is accountable by the balance between gravitational and retentive forces. (C) 2007 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.apsusc.2007.07.171

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  • Slipping and rolling ratio of sliding acceleration for a water droplet sliding on fluoroalkylsilane coatings of different roughness

    Shunsuke Suzuki, Akira Nakajima, Munetoshi Sakai, Yuu Sakurada, Naoya Yoshida, Ayako Hashimoto, Yoshikazu Kameshima, Kiyoshi Okada

    CHEMISTRY LETTERS   37 ( 1 )   58 - 59   2008年1月

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    記述言語:英語   出版者・発行元:CHEMICAL SOC JAPAN  

    The effect of surface roughness on the internal fluidity of a water droplet during sliding on an inclined Si surface treated fluoroalkylsilane (FAS) was investigated using particle image velocimetry (PIV). A water droplet slid down by caterpillar-like rotation flow with or without slippage on the solid-liquid interface. The slipping/rolling ratio on the sliding acceleration depended on the surface roughness; the droplet advanced on the rough surface mainly by the rolling mechanism.

    DOI: 10.1246/cl.2008.58

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  • Direct Measurement of the Motion of Water Droplets on a Hydrophobic Self-assembled Monolayer Surface under Airflow

    A. Hashimoto, M. Sakai, N. Yoshida, S. Suzuki, Y. Kameshima, A. Nakajima

    J. Surf. Finishing Soc. Jpn.   59 ( 12 )   907 - 912   2008年

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  • 高酸量の酸化物ゾル/スメクタイト複合体の作製

    亀島 欣一, 岡田 清

    化学工業   59 ( 5 )   337 - 342   2008年

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  • Properties of TiO2 prepared by acid treatment of BaTiO3

    Kiyoshi Okada, Tomoki Yanagisawa, Yoshikazu Kameshima, Akira Nakajima

    MATERIALS RESEARCH BULLETIN   42 ( 11 )   1921 - 1929   2007年11月

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    記述言語:英語   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    TiO3 powders were prepared by acid treatment of BaTiO3 and their properties were investigated. The BaTiO3 powder was subjected to HNO3 in concentrations ranging from 10(-3) to 8 M at 90 degrees C for 0.5-6 h. Dissolution of BaTiO3 and precipitation of TiO2 occurred at acid concentrations of 2-5 M. BaTiO3 dissolves completely to form a clear solution at reaction times of 0.5-1 h, but a rutile precipitate is formed after 2 h of acid treatment. By contrast, anatase is precipitated by adjusting the pH of the clear solution to 2-3 using NaOH or NH4OH solution. The rutile crystals were small and rod-shaped, consisting of many small coherent domains connected by grain boundaries with small inclination angles and edge dislocations, giving them a high specific surface area (S-BET). With increasing HNO3 concentration, the SBET value increased from 100 to 170 m(2)/g while the crystallite size decreased from 25 to 11 nm. The anatase crystals obtained here were very small equi-axial particles with a smaller crystallite size than the rutile and S-BET values of about 270 m(2)/g (higher than the rutile samples). The photocatalytic activity of these TiO3 was determined from the decomposition rate of Methylene Blue under ultraviolet irradiation. Higher decomposition rates were obtained with larger crystallite sizes resulting from heat treatment. The maximum decomposition rates were obtained in samples heated at 500-600 degrees C. The photocatalytic activity of the TiO3 was found to depend more strongly on the sample crystallite size than on S-BET. (C) 2006 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.materresbull.2006.12.011

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  • Synthesis and characterization of mesoporous silica from selectively acid-treated saponite as the precursors

    Kiyoshi Okada, Hisako Yoshizaki, Yoshikazu Kameshima, Akira Nakajima, Chengala D. Madhusoodana

    JOURNAL OF COLLOID AND INTERFACE SCIENCE   314 ( 1 )   176 - 183   2007年10月

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    記述言語:英語   出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    Mesoporous silicas were synthesized by hydrothermal treatment of selectively acid-treated saponite (an ideal structural formula: Na1/3Mg3-(Si11/3Al1/3)O-10(OH)(2)), having a 2:1 type layered structure as the silica source and its porous properties were examined and compared with that from kaolinite (an ideal structural formula: Al2Si2O5(OH)(4)), having a 1:1 type layered structure. Synthetic saponite was selectively leached in H2SO4 solutions with various concentrations (0.05-1 M) at 70 degrees C for 0.5 h. The resulting products (precursors) were mixed with cetyltrimethylammonium bromide (CTABr), NaOH and H2O, hydrothermally treated at 110 degrees C and removed the CTABr by calcining at 560 degrees C. A hexagonal mesoporous phase was obtained with higher Si/(Al(+Mg)) ratios of the resulting precursors. The XRD patterns of these products show the peaks assigned by a hexagonal lattice with a(0) = 4.0-4.6 nm and the crystatlinity becomes higher with higher Si/(Al(+Mg)) ratios of the precursors. The specific surface area (S-BET) values of the present mesoporous silicas range from 800 to 1100 m(2)/g at CTABr/precursor = 0.1 and although they are not as high as those from precursors prepared from calcining and acid-treatment of kaolinite (1420 m(2)/g), they are increased to 14001500 m2/g by increasing the ratio CTABr/precursor >= 0.2. The reason for the difference in the optimum preparation conditions between saponite and kaolinite may be attributed to the difference in the linkage of the SiO4 tetrahedra in these precursors (i.e. layered or framework structures), which result in great differences in the selective leaching rates and structures of the resulting silica-rich products. (c) 2007 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.jcis.2007.05.036

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  • Freezing of water droplets on silicon surfaces coated with various silanes

    Shunsuke Suzuki, Akira Nakajima, Naoya Yoshida, Munetoshi Sakai, Ayako Hashimoto, Yoshikazu Kameshima, Kiyoshi Okada

    CHEMICAL PHYSICS LETTERS   445 ( 1-3 )   37 - 41   2007年9月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    The freezing behavior of a supercooled water droplet on a silicon surface treated with using various silanes was observed directly using a high-speed camera system. Freezing stability is best ensured by heterogeneous nucleation from a three-phase (solid-liquid-air)- contact line. Differential scanning calorimetry measurements revealed that the freezing temperature of a supercooled water droplet on a fluoro-alkylsilane monolayer was lower than that of alkylsilane. Interaction between the fluorocarbon and water molecule, in addition to structural characteristics of silanes, might play an important role in the heterogeneous nucleation of supercooled water. (C) 2007 Published by Elsevier B.V.

    DOI: 10.1016/j.cplett.2007.07.066

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  • Effect of electrification conditions on the freezing of supercooled water droplets on a hydrophobic coating

    Akira Nakajima, Akihito Imase, Shunsuke Suzuki, Naoya Yoshida, Munetoshi Sakai, Ayako Hashimoto, Yoshikazu Kameshima, Hiroshi Toshiyoshi, Kiyoshi Okada

    CHEMISTRY LETTERS   36 ( 8 )   1020 - 1021   2007年8月

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    記述言語:英語   出版者・発行元:CHEMICAL SOC JAPAN  

    The effects of electrification processes on ice nucleation on an octadecanethiol (ODT) coating were investigated under two different conditions. Electrification provides the driving force of the movement to the three-phase contact line. This change promotes ice nucleation on the supercooled water droplet. In contrast, electrification before cooling inhibits freezing, probably because of the limitation of orientational freedom by the interaction between the surface charge and the dipole moment of water molecules.

    DOI: 10.1246/cl.2007.1020

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  • Hydrophobicity and freezing of a water droplet on fluoroalkylsilane coatings with different roughnesses

    Shunsuke Suzuki, Akira Nakajima, Naoya Yoshida, Munetoshi Sakai, Ayako Hashimoto, Yoshikazu Kameshima, Kiyoshi Okada

    LANGMUIR   23 ( 17 )   8674 - 8677   2007年8月

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    記述言語:英語   出版者・発行元:AMER CHEMICAL SOC  

    Smooth (Ra approximate to 0. 1 nm) and rough (Ra approximate to 20 nm) coatings of 1H, 1H,2H,2H-perfluorodecyltrimethoxysilane (FAS17) were prepared by controlling process conditions. The water contact angles for the smooth and rough coatings were similar (107 degrees and 110 degrees, respectively), but their sliding angles differed considerably (10 degrees and 27 degrees, respectively). The surface potential on the smooth coating, assessed using Kelvin force microscopy, showed a sharp distribution, but that on the rough coating ranged widely, implying large chemical heterogeneity including residual SiOH groups. The freezing temperature of a supercooled water droplet on the rough coating was higher than that on the smooth coating.

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  • Bioactivity of CaSiO3/poly-lactic acid (PLA) composites prepared by various surface loading methods of CaSiO3 powder

    Kiyoshi Okada, Fumikazu Hasegawa, Yoshikazu Kameshima, Akira Nakajima

    JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE   18 ( 8 )   1605 - 1612   2007年8月

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    記述言語:英語   出版者・発行元:SPRINGER  

    Mixing bioactive ceramic powders with polymers is an effective method for generating bioactivity to the polymer-matrix composites but it is necessary to incorporate up to 40 vol% of bioactive ceramic powder. However, such a high mixing ratio offsets the advantages of the flexibility and formability of polymer matrix and it would be highly advantageous to lower the mixing ratio. Since surface loading of ceramic powders in the polymer is thought to be an effective way of reducing the mixing ratio of the ceramic powder while maintaining bioactive activity, CaSiO3/poly-lactic acid (PLA) composites were prepared by three methods; (1) casting, (2) spin coating and (3) hot pressing. In methods (1) and (2), a suspension was prepared by dissolving PLA in chloroform and dispersing CaSiO3 powder in it. The suspension was cast and dried to form a film in the case of method (1) while it was spincoated on a PLA substrate in method (2). In method (3), CaSiO3 powder was surface loaded on to a PLA substrate by hot-pressing. The bioactivity of these samples was investigated in vitro using simulated body fluid (SBF). Apatite formation was not observed in the samples prepared by method (1) but some apatite formation was achieved by mixing polyethylene glycol (PEG) with the PLA, producing a porous polymer matrix. In method (2), apatite was clearly observed after soaking for 7 days. Enhanced apatite formation was observed in method (3), the thickness of the resulting apatite layers becoming about 20 mu m after soaking for 14 days. Since the amount of CaSiO3 powder used in these samples was only <= 0.4 vol%, it is concluded that this preparation method is very effective in generating bioactivity in polymer-matrix composites by loading with only very small amounts of ceramic powder.

    DOI: 10.1007/s10856-007-3059-9

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  • Photoinduced surface roughness variation in polycrystalline TiO2 thin films under different atmospheres

    Naoki Arimitsu, Akira Nakajima, Ken-Ichi Katsumata, Tadashi Shiota, Toshiya Watanabe, Naoya Yoshida, Yoshikazu Karneshima, Kiyoshi Okada

    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY   190 ( 1 )   53 - 57   2007年7月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE SA  

    For this study, we evaluated photoinduced surface roughness variation of polycrystalline anatase thin films under different atmospheres using atomic force microscopy (AFM). A TiO2 thin film with large grains was prepared using the sol-gel process and vacuum ultraviolet (VUV) irradiation before firing. Upon UV illumination, the surface image became blurred with an apparent surface roughness increase in ambient air. The appearance of this image change was delayed in dry air, and was not observed in dry nitrogen. These results imply that this photoinduced surface change is related to water adsorption from the atmosphere. (c) 2007 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jphotochem.2007.03.013

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  • Bioactivity of CaSiO3/poly-lactic acid (PLA) composites prepared by various surface loading methods of CaSiO3 powder

    Kiyoshi Okada, Fumikazu Hasegawa, Yoshikazu Kameshima, Akira Nakajima

    JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE   18 ( 5 )   899 - 907   2007年5月

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    記述言語:英語   出版者・発行元:SPRINGER  

    Mixing bioactive ceramic powders with polymers is an effective method for generating bioactivity to the polymer-matrix composites but it is necessary to incorporate up to 40 vol% of bioactive ceramic powder. However, such a high mixing ratio offsets the advantages of the flexibility and formability of polymer matrix and it would be highly advantageous to lower the mixing ratio. Since surface loading of ceramic powders in the polymer is thought to be an effective way of reducing the mixing ratio of the ceramic powder while maintaining bioactive activity, CaSiO3/poly-lactic acid (PLA) composites were prepared by three methods; (1) casting, (2) spin coating and (3) hot pressing. In methods (1) and (2), a suspension was prepared by dissolving PLA in chloroform and dispersing CaSiO3 powder in it. The suspension was cast and dried to form a film in the case of method (1) while it was spin-coated on a PLA substrate in method (2). In method (3), CaSiO3 powder was surface loaded on to a PLA substrate by hot pressing. The bioactivity of these samples was investigated in vitro using simulated body fluid (SBF). Apatite formation was not observed in the samples prepared by method (1) but some apatite formation was achieved by mixing polyethylene glycol (PEG) with the PLA, producing a porous polymer matrix. In method (2), apatite was clearly observed after soaking for 7 days. Enhanced apatite formation was observed in method (3), the thickness of the resulting apatite layers becoming about 20 mu m after soaking for 14 days. Since the amount of CaSiO3 powder used in these samples was only <= 0.4 vol%, it is concluded that this preparation method is very effective in generating bioactivity in polymer-matrix composites by loading with only very small amounts of ceramic powder.

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  • Preparation of cobalt-titanium dioxide nanocomposite films by combining inverse micelle method and plasma treatment

    Naoki Arimitsu, Akira Nakajima, Yoshikazu Kameshima, Yuko Shibayama, Hisashi Ohsaki, Kiyoshi Okada

    MATERIALS LETTERS   61 ( 11-12 )   2173 - 2177   2007年5月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    We investigated the processing of a metal nanogranular thin film of Co-Ti-O system by combining a colloidal wet process (inverse micelle method) and a dry process (plasma treatment). Both TEM and EDS analyses revealed,that the film was prepared along with suppression of metal cobalt nanoparticles' oxidization. Results showed that plasma processing provides new possibilities for processing of materials that are difficult to prepare under equilibrium conditions. (c) 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.matlet.2006.08.044

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  • Mn-Ce/ZSM5 as a new superior catalyst for NO reduction with NH3

    Gabriela Carja, Yoshikazu Kameshima, Kiyoshi Okada, Changalla D. Madhusoodana

    APPLIED CATALYSIS B-ENVIRONMENTAL   73 ( 1-2 )   60 - 64   2007年4月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Mn-Ce/ZSM-5 catalyst prepared in an aqueous phase at 423 K exhibits a broad temperature window (517-823 K) for high NO conversions (75-100%) in the process of selective catalytic reduction (SCR) by NH3 even in the presence of H2O and SO2. Both the zeolite matrix and the over-exchanged amounts of manganese and cerium contribute to obtain a complex structure that owns microporous-mesoporous characteristics and specific surface properties. (c) 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.apcatb.2006.06.003

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  • Image analysis system for evaluating sliding behavior of a liquid droplet on a hydrophobic surface

    Munetoshi Sakai, Ayako Hashimoto, Naoya Yoshida, Shunsuke Suzuki, Yoshikazu Kameshima, Akira Nakajima

    REVIEW OF SCIENTIFIC INSTRUMENTS   78 ( 4 )   045103   2007年4月

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    記述言語:英語   出版者・発行元:AMER INST PHYSICS  

    An analysis system was developed to evaluate the sliding behavior of a liquid droplet on a hydrophobic surface. This system enables continuous and simultaneous measurement of both the sliding acceleration and shape deformation during the sliding of a liquid droplet. Moreover, the velocity vector of the internal fluidity of a sliding droplet was obtained by employing particle image velocimetry in the analysis system. This evaluation method pioneers the measurement of the dynamic wettability of a hydrophobic solid surface.

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  • Simultaneous uptake of ammonium and phosphate ions by compounds prepared from paper sludge ash

    Kiyoshi Okada, Yosuke Ono, Yoshikazu Kameshima, Akira Nakajima, Kenneth J. D. MacKenzie

    JOURNAL OF HAZARDOUS MATERIALS   141 ( 3 )   622 - 629   2007年3月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Al-containing CaO-SiO2-H2O phases were prepared by hydrothermal treatment of mixtures of paper sludge ash (PSA) with various silica and calcia sources and their properties were determined with particular reference to the simultaneous uptake of ammonium and phosphate ions, which are implicated in the eutrophication of lakes and ponds. After examination of various silica and calcia sources, Ca(OH)(2) and SiO2 Sol were selected as the most appropriate starting materials. Dry milling was found to be superior to wet milling in avoiding contamination from the milling media during mixing. Nine samples with three different Ca/Si ratios and Al2O3 contents were prepared with various mass ratios of Ca(OH)(2), PSA and SiO2. The chemical compositions of the hydrothermal products of these mixtures moved towards the tieline of CaSiO3-PSA, with respect to the starting compositions. The major phase formed in all samples was poorly crystalline C-S-H(I), with hydroxysodalite also formed in the Al-containing mixtures. All the products showed a capacity for the simultaneous uptake of ammonium and phosphate ions. The saturated sorption capacities calculated from the Langmuir equation ranged from 0.9 to 2.4 mmol/g for the ammonium ion and from 3.3 to 5.2 mmol/g for the phosphate ion. Since the sorption capacities for both ions increased with increasing Ca contents of the product, substitution of Ca2+ for NH4+ and the formation of calcium phosphate phases such as apatite and brushite by precipitation are thought to be the main sorption mechanisms. (c) 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jhazmat.2006.07.017

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  • Effect of TiO2 powder addition on sonochemical destruction of 1,4-dioxane in aqueous systems

    A. Nakajima, H. Sasaki, Y. Kameshima, K. Okada, H. Harada

    Ultrasonics Sonochem.   14 ( 2 )   197 - 200   2007年2月

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  • Deformation and motion by gravity and magnetic field of a droplet of water-based magnetic fluid on a hydrophobic surface

    Hiroko Asakura, Akira Nakajima, Munetoshi Sakai, Shunsuke Suzuki, Yoshikazu Kameshima, Kiyoshi Okada

    APPLIED SURFACE SCIENCE   253 ( 6 )   3098 - 3102   2007年1月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Motion and deformation of a water-based magnetic fluid on a hydrophobic surface were investigated under gravity and a magnetic field. Surface energy and the resultant contact angle of the magnetic fluid depend on the surfactant concentration. The fluid viscosity is governed mainly by magnetite concentration. The front edge of the droplet moved under a weak external field. The rear edge required a higher external field for movement. The forces of gravity and the magnetic field for moving of the front edge are almost equal. However, those of the rear edge are different. The motion of magnetic fluids by an external field depends on concentrations of surfactants and magnetic particles, the external field, and experimental assembly. (c) 2006 Elsevier B.V. All rights reserved.

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  • Simultaneous uptake of Ni2+, NH4+ and PO43- by amorphous CaO-Al2O3-SiO2 compounds

    Kiyoshi Okada, Megumi Shimazu, Yoshikazu Kameshima, Akira Nakajima, Kenneth J. D. MacKenzie

    JOURNAL OF COLLOID AND INTERFACE SCIENCE   305 ( 2 )   229 - 238   2007年1月

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    記述言語:英語   出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    Simultaneous uptake of Ni2+, NH4+, and PO43- by amorphous CaO-Al2O3-SiO2 (C-A-S) compounds was investigated using batch and column methods. Fifteen different C-A-S samples with systematically varied chemical compositions were prepared by coprecipitation from ethanol-water solutions containing Ca(NO3)(2)(.)4H(2)O, Al(NO3)(3)(.)9H(2)O, and Si(OC2H5)(4), using NH4OH as the precipitating agent. The resulting precipitates were dried and heated at various temperatures to produce the C-A-S samples, which were then characterized by XRD, FTIR, solid state MAS NMR, DTA-TG, and N-2 adsorption. All the C-A-S samples prepared at 600-900 degrees C were amorphous, apart from the CaO-rich samples. Simultaneous uptake of Ni2+, NH4+, and PO43- was determined by a batch method using a solution with an initial concentration of 2 mM. In these experiments, the uptake abilities of the C-A-S samples for Ni2+ and PO43- were high, but were relatively low for NH+. The uptake abilities for Ni2+ and PO43- increased but that for NH+ decreased as the silica content in the C-A-S decreased, suggesting that similar uptake mechanisms (ion substitution and/or precipitation) are operating for Ni2+ and PO43- but the uptake mechanism for NH4+ is different (physical adsorption). The column experiments indicate that the order of uptake ability of C-A-S for the three ions is Ni-4(+) << PO43- < Ni2+. Although the silica content of the C-A-S does not have the expected influence on the uptake of these three ions, for NH4+ it plays an important role in the formation of the amorphous phase and also in the suppression of Ca2+ and/or Al3+ release from the C-A-S during the uptake experiments. The optimum uptake properties of the C-A-S can thus be controlled by adjusting the chemical compositions and heating conditions under which the samples are prepared. (c) 2006 Elsevier Inc. All rights reserved.

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  • Effects of vacuum ultraviolet light illumination on the residual stress in sol-gel-derived titanium dioxide films

    Naoki Arimitsu, Akira Nakajima, Keisuke Saito, Yoshikazu Kameshima, Kiyoshi Okada

    CHEMISTRY LETTERS   36 ( 1 )   106 - 107   2007年1月

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    記述言語:英語   出版者・発行元:CHEMICAL SOC JAPAN  

    This study investigated effects of vacuum ultraviolet (VUV) illumination on the residual stress of sol-gel-derived titanium dioxide (TiO2) films. After firing at 500 degrees C, VUV pre-illumination to TiO2 precursor film decreases residual stress more than 30%. This effect is explained by the great shrinkage that occurs during VUV illumination.

    DOI: 10.1246/cl.2007.106

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  • The textural properties of iron substituted hydrotalcites obtained in a tailored aqueous-organic synthesis medium

    Gabriela Carja, Hiromi Obata, Yoshikazu Kameshima, Kiyoshi Okada

    MICROPOROUS AND MESOPOROUS MATERIALS   98 ( 1-3 )   150 - 155   2007年1月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Iron containing layered double hydroxides with specific textural properties are synthesized by using tailored compositions of an aqueous-organic synthesis medium as a controlled variable synthesis parameter. SEM analysis points out that the nature of the organic solvent and the aqueous-organic solvent ratio contribute in establishing not only different sizes and/or shapes of the hydrotalcite-like particles, but also distinct features of their organisation and interconnection pattern. As a consequence, interparticle voids with different characteristics emerge giving rise to specific mesoporous properties of the studied samples. The S-BET value is 41 m(2)/g for the sample synthesized in water/glycerol/cyclohexane, reaches 108 m(2)/g for the sample obtained in water/glycerol/ethanol whereas the corresponded V-p value increases from 0.24 ml/g to 0.41 ml/g respectively. The possibility to shape the micromorphology properties of layered double hydroxides can contribute in designing and obtaining well established nanoporous properties for these materials. (C) 2006 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.micromeso.2006.08.026

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  • Preparation of Lotus-type Porous Ceramics with High Water Pump-up Ability and Its Cooling Effect by Water Vapor Evaporation

    K. Okada, Y. Kameshima, A. Nakajima, C. D. Madhusoodana

    J. Heat Island Inst. Int.   2   1 - 5   2007年

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  • 層状ナノクリスタル酸化マンガンと炭素の複合化による高機能電極材料の作製

    亀島 欣一

    (財)村田学術振興財団年報   21   49 - 56   2007年

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  • 水と撥水性固体表面との相互作用に対する計算化学的検討

    亀島欣一

    中島「ナノウェッティング」プロジェクト 研究概要集   31 - 40   2007年

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  • 環境に優しい層状物質:層状複水酸化物

    亀島 欣一

    マテリアルインテグレーション   20 ( 7-8 )   101 - 103   2007年

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  • Gas permeability and mechanical properties of porous alumina ceramics with unidirectionally aligned pores

    Toshihiro Isobe, Yoshikazu Kameshima, Akira Nakajima, Kiyoshi Okada, Yuji Hotta

    Journal of the European Ceramic Society   27 ( 1 )   53 - 59   2007年

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    記述言語:英語  

    Porous alumina ceramics having unidirectionally aligned cylindrical pores were prepared by extrusion method and compared with porous ceramics having randomly distributed pores prepared by conventional method, and their gas permeability and mechanical properties were investigated. SEM micrographs of the porous alumina ceramics prepared by the extrusion method using nylon fibers as the pore former showed excellent orientation of cylindrical pores. The bending strength and Weibull modulus of the extruded porous alumina ceramics with 39% porosity were 156 MPa and 17, respectively. These mechanical properties of extruded samples were higher than those of the conventional porous alumina ceramics. The strength decreased from 156 to 106 MPa with increasing pore size from 8.5 to 38 μm. The gas permeability of the extrusion samples is higher than that of the conventional samples and increased with increasing of porosity and pore size. © 2006.

    DOI: 10.1016/j.jeurceramsoc.2006.02.030

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  • Preparation and properties of porous alumina ceramics with uni-directionally oriented pores by extrusion method using a plastic substance as a pore former

    Toshihiro Isobe, Yoshikazu Kameshima, Akira Nakajima, Kiyoshi Okada

    Journal of the European Ceramic Society   27 ( 1 )   61 - 66   2007年

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    記述言語:英語  

    Porous alumina ceramics with uni-directionally aligned pores were prepared by an extrusion method using 0-40 vol.% poly (vinyl acetate) (PVAC) as the pore former. A paste was prepared by mixing 25 mass% distilled water, 4 mass% methylcellulose, 8 mass% oleic acid and 0.8 mass% ammonium poly (carboxylic acid). This paste was molded into a 10 mm Ø body using a ram-type extruder, dried at room temperature for 24 h, calcined at 600 °C for 1 h and sintered at 1500 °C for 2 h in air. The PVAC added to the paste was homogeneously dispersed and formed particles 0.1-150 μm in size which extended in the extrusion direction and were converted to through-hole pores after sintering. The resulting pore size distribution in the samples was bimodal, centered at about 0.4 μm with a broad peak at about 70 μm dia. The resulting porous alumina ceramics showed high gas permeability because of their uni-directionally oriented through-hole pore structure. © 2006 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.jeurceramsoc.2006.05.079

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  • Glass-ceramics prepared from sludge generated by a water purification plant

    Tomohiro Toya, Aiko Nakamura, Yoshikazu Kameshima, Akira Nakajima, Kiyoshi Okada

    CERAMICS INTERNATIONAL   33 ( 4 )   573 - 577   2007年

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    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    Glass-ceramics were prepared from sludge generated in a water purification process. The main constituents of this sludge were Si0(2) and Al2O3, with considerable amounts of Fe2O3 and MnO also present. The batch composition of the parent glass was adjusted to be close to the composition of the eutectic point in the CaO-Al2O3-SiO2 System by mixing the sludge with CaCO3 and waste soda-lime glass. The samples were melted at 1300 degrees C for 2 h and quenched in water. The resulting glass cullet was ground to < 100 mesh in a ball mill, uniaxially pressed to form green bodies and fired at 700-1250 degrees C to densify and crystallize. Crystallization occurred at > 850 degrees C, forming gehlenite (Ca2Al2SiO7) and wollastonite (CaSiO3) above 900-950 degrees C. The color of the sample changed from black to yellow-brown upon crystallization. The average four-point bending strength and Vickers microhardness of the glass-ceramics heated at 1000 degrees C (99 MPa and 5.2 GPa) was comparable with the values of commercial glass-ceramics. The chemical durability in acid and alkali solutions was 17.7 and 0.23 mg/cm(2), respectively, showing excellent durability in alkali solution. (c) 2006 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

    DOI: 10.1016/j.ceramint.2005.11.009

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  • Processing of W-based Heteropolyacid-LDH Composites

    S. Yanagida, A. Nakajima, Y. Kameshima, K. Okada

    J. Ion Exchange   18 ( 4 )   270 - 275   2007年

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  • Preparation and Porous Properties of Mesoporous Silica from Selectively Acid-treated Saponite

    Kiyoshi OKADA, Hisako YOSHIZAKI, Yoshikazu KAMESHIMA, Akira NAKAJIMA, Chengala D. MADHUSOODANA

    J. Colloid Interf. Sci.   314 ( 1 )   176   2007年

  • 高揚水レンコン型多孔質セラミックス材料の作製とその蒸発冷却効果

    岡田 清, 亀島欣一, 中島 章, chengala D. MADHUSOODANA

    ( 2 )   1 - 5   2007年

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  • Effect of applying voltage on photocatalytic destruction of 1.4-dioxane in aqueous system

    Sayaka Yanagida, Akira Nakajima, Yoshikazu Kameshima, Kiyoshi Okada

    CATALYSIS COMMUNICATIONS   7 ( 12 )   1042 - 1046   2006年12月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    In the current work, we prepared a TiO2 coating on stainless mesh using electrophoretic deposition (EPD), and applied voltage to a stainless mesh to examine the synergy effect on photocatalysis of both 1,4-dioxane and ethylene glycol diformate (EGDF), a main intermediate of the photocatalysis of 1,4-dioxane. The photocatalytic decomposition rate of 1,4-dioxane depends on applying voltage under diffusion-limited reaction conditions. Ethylene glycol diformate and 1,4-dioxane exhibited inverse voltage dependence. Voltage swing provides high-efficiency photocatalysis of 1,4-dioxane while suppressing EGDF formation. This method will be effective for a photocatalysis system containing several chemicals, each with different voltage dependence. (c) 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.catcom.2006.05.016

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  • Effects of vacuum ultraviolet light illumination and seeding on crystallization of sol-gel-derived titanium dioxide precursor films using plasma treatment

    Naoki Arimitsu, Akira Nakajima, Yoshikazu Kameshima, Yuko Shibayama, Hisashi Ohsaki, Kiyoshi Okada

    SURFACE & COATINGS TECHNOLOGY   201 ( 6 )   3038 - 3043   2006年12月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE SA  

    The current study investigated the effects of vacuum ultraviolet (VUV) illumination and seeding on the crystallization of sol-gel-derived titanium dioxide (TiO2) precursor films on Si(100) and Pyrex glass substrates by plasma treatment. To improve the film microstructure to one that is amenable to crystallization, VUV illumination is found to be effective. However, crystallization behavior suggests that a proper balance between decomposition of organic compounds and densification by dehydration is important for the treatment. The combination of seeding and VUV illumination is effective even for crystallization by plasma treatment on both Si(100) and Pyrex glass substrates. (c) 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.surfcoat.2006.06.014

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  • Effect of dispersant on paste rheology in preparation of porous alumina with oriented pores by extrusion method

    Toshihiro Isobe, Yoshikazu Karneshima, Akira Nakajima, Kiyoshi Okada, Yuji Hotta

    JOURNAL OF POROUS MATERIALS   13 ( 3-4 )   269 - 273   2006年10月

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    記述言語:英語   出版者・発行元:SPRINGER  

    The effect of additives on paste rheology was investigated for preparation of porous ceramics with uni-directionally aligned cylindrical pores. Ammonium polycarboxylic acid (APA) used as a dispersant and it was adsorbed on alumina powder surface. The adsorption isotherm of APA was fitted by Langmuir equation. The saturated monolayer adsorption was 5.9 mg/g. The apparent viscosity became a minimum at 0.8 mass % of APA corresponding to 71.2 mPa.s. This APA amount of 5.6 mg/g, is in good agreement with the observed APA amount. Since the nylon 66 fibers (0-35 vol. %) mixed with the alumina powder have a strong interaction with each other, they became twisted and agglomerated. This agglomeration increased with increasing fiber content but decreased by adding oleic acid. The pastes with added oleic acid were capable of being extruded at higher pressure, The obtained porous alumina ceramics showed highly oriented cylindrical pores parallel to the extrusion direction. The pore orientation was higher in the oleic acid added pastes than those without oleic acid. The added nylon 66 fibers are mostly converted to pores while maintaining the original shape after sintering. The pore size distribution of the obtained porous ceramics measured by mercury porosimetry method showed a peak at about 4 tim which is apparently smaller than that observed in the SEM photographs and the obtained result is considered to be corresponding to the necks formed by fiber contacts.

    DOI: 10.1007/s10934-006-8015-4

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  • Effect of grinding and heating on Ni2+ uptake properties of waste paper sludge

    Vinay Kumar Jha, Yoshikazu Kameshima, Akira Nakajima, Kivoshi Okada, Kenneth J. D. MacKenzie

    JOURNAL OF ENVIRONMENTAL MANAGEMENT   80 ( 4 )   363 - 371   2006年9月

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    記述言語:英語   出版者・発行元:ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD  

    Uptake properties of Ni2+ were examined for unmilled and milled paper sludge calcined at various temperatures to develop a new usage of waste paper sludge. Since paper sludge mainly consists of cellulose ([C6H10O5](n)) fibers, calcite (CaCO3) kaolinite (Al2Si2O5(OH)(4)) and talc (Mg3Si4O10(OH)(2)), amorphous and crystalline CaO(MgO)-Al2O3-SiO2 compounds are formed by calcining paper sludge. Wet and dry milling treatments were performed to accelerate solid-state reaction to form the above mentioned target compounds. The crystalline phases originally present decompose at increasing calcining temperature (up to 800 degrees C) in the order cellulose < kaolinite < calcite < talc. An amorphous phase was formed in the samples below 800 degrees C and the temperatures changed depending on the milling conditions in the order dry milled < wet milled < unmilled. Gehlenite (Ca2Al2SiO7) and anorthite (CaAl2Si2O8) crystallized by calcining at 900 degrees C in all the samples, formed by solid-state reaction of kaolinite with calcite. The Si-29 and Al-27 MAS NMR spectra of the amorphous samples were similar to those of crystalline phases, suggesting that the local structure of the amorphous phase resembles the crystalline structures. Maximum Ni2+ uptake occurred in the dry-milled samples calcined at 600 degrees C, and wet-milled and unmilled samples calcined at 700 degrees C, respectively. The dry-milled and calcined at 600 degrees C sample showed the highest Ni2+ uptake (4.54 mmol/g) and an uptake rate of 3.5 mu mol/(g min). (c) 2006 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.jenvman.2005.09.014

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  • Zeolite coating on foamed stainless steel by in-situ crystallization method

    H. Asakura, C. D. Madhusoodana, Y. Kameshima, A. Nakajima, K. Okada

    JOURNAL OF ELECTROCERAMICS   17 ( 1 )   31 - 36   2006年9月

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    記述言語:英語   出版者・発行元:SPRINGER  

    Faujasite-type zeolite films were prepared on foamed stainless steel by the in-situ crystallization method. Precursor solutions were prepared by dissolving water glass and NaAlO2 in a NaOH solution and aged at room temperature for two days. The concentrations of the starting materials were varied from 0.29 to 2.3 M( in SiO2 concentration) keeping the molar ratios of Na2O: SiO2: Al2O3 fixed at 3.6: 3.0: 1.0. The foamed stainless steel substrate had about 90% of porosity and an average pore size of 600 mu m. It was dip-coated in the precursor solution four times, then hydrothermally treated at 80 degrees, 110 degrees and 150 degrees C for 6 - 48 h. The XRD patterns and SEM photographs revealed that faujasite-type zeolite was formed predominantly at a SiO2 concentration of 1.1 M, temperature of 110 degrees C and duration of 24 h, with a product particle size of 2 - 5 mu m. At higher concentrations of the precursor solution, hydroxylsodalite becomes the major product rather than faujasite-type zeolite. The adherence strength of the zeolite grains deposited on the foamed stainless steel is higher in the in-situ crystallization method than when a conventional solution method is used. Thus, the in-situ crystallization method is concluded to be effective for preparing zeolite films even on metal substrates.

    DOI: 10.1007/s10832-006-9931-z

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  • Preparation and sorption properties of porous materials from refuse paper and plastic fuel (RPF)

    Z. Kadirova, Y. Kameshima, A. Nakajima, K. Okada

    JOURNAL OF HAZARDOUS MATERIALS   137 ( 1 )   352 - 358   2006年9月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Porous materials consisting of activated carbon and amorphous CaO-Al2O3-SiO2 (CAS) compound were prepared from refuse paper and plastic fuel (RPF), (a mixture of old paper and plastic) by carbonizing and/or activating treatments. Samples formed by chemical activation using K2CO3 showed a high specific surface area (S-BET) of 1330 m(2)/g but a lower ash content due to being washed after activation. By contrast, samples prepared by physical activation using steam showed rather lower SBET (510 m(2)/g) due to higher ash contents. The physically activated samples showed much higher uptake properties for Ni2+ (a representative heavy metal) and phosphate ions (a representative of a harmful oxyanion) than the chemically activated samples because of the higher content of amorphous CAS in the former samples. By contrast, the chemically activated samples showed higher uptake for methylene blue (MB, a representative organic material) than the physically activated samples because of the higher activated carbon content of higher surface area. Although differences in the sorption properties for Ni2+, phosphate ion and MB were found between the physically and chemically activated samples, both samples show excellent multiple sorption properties for cation-anion combinations and inorganic-organic sorbents. (c) 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jhazmat.2006.02.008

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  • Relationship between sliding acceleration of water droplets and dynamic contact angles on hydrophobic surfaces

    Munetoshi Sakai, Jeong-Hwan Song, Naoya Yoshida, Shunsuke Suzuki, Yoshikazu Kameshima, Akira Nakajima

    SURFACE SCIENCE   600 ( 16 )   L204 - L208   2006年8月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    This study measured sliding acceleration of water droplets on hydrophobic solid surfaces and used expanding and contracting method to compare that value with dynamic contact angles. Sliding action of the droplet was classified into three motion categories: constant accelerated motion, constant velocity and stasis. Differences exist in the dependencies of contact radius and the injection-suction rate in dynamic contact angle hysteresis according to these categories. This method is an effective indicator of water droplets' sliding acceleration. (c) 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.susc.2006.06.039

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  • Preparation of sodium oleate/layered double hydroxide composites with acid-resistant properties

    Y Kameshima, H Yoshizaki, A Nakajima, K Okada

    JOURNAL OF COLLOID AND INTERFACE SCIENCE   298 ( 2 )   624 - 628   2006年6月

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    記述言語:英語   出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    Mg-Al-CO3 type layered double hydroxides (LDHs) with Mg/Al ratios ranging from 2 to 5 were synthesized by coprecipitation. Composites with sodium oleate/LDH were prepared by ion exchange and reconstruction of the LDH in sodium oleate solution. The amount of sodium oleate in the composites prepared by this reconstruction method was higher than that in samples prepared by the ion-exchange method. The basal spacings of the LDHs increased to 3.9 and 1.8 nm after synthesis of the composites, these spacings being in good agreement with models based on the assumption that the oleate ions are intercalated as bilayer and/or micelle structures, and as monolayers in the LDH interlayers, respectively. The number of sorbed oleate ions was higher than calculated from the anion-exchange capacities of the LDHs in most of the samples, increasing as the Mg/Al ratios of the LDHs were increased from 2 to 5. These results suggest that the oleate ions are present not only in the interlayers but also on the surfaces of the LDH particles. The acid-resistant properties of the composites were found to be much higher than for the pure LDHs. It is thus confirmed that the surfaces of the LDH particles in the composites are mostly covered with sorbed oleate ions and that the composites are good candidates as drug delivery materials. (c) 2006 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.jcis.2006.01.033

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  • Photoinduced surface roughness variation in polycrystalline TiO2 thin films

    Ken-ichi Katsumata, Akira Nakajima, Tadashi Shiota, Naoya Yoshida, Toshiya Watanabe, Yoshikazu Kameshima, Kiyoshi Okada

    Journal of Photochemistry and Photobiology A: Chemistry   180 ( 1-2 )   75 - 79   2006年5月

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    記述言語:英語  

    Photoinduced microstructural changes in transparent anatase thin films with large-grain polycrystallites (-200 nm) were evaluated using atomic force microscopy (AFM). Films were subjected to a vacuum ultraviolet (VUV) pretreatment before heating at 500 °C. Photoinduced wettability of the films was subsequently confirmed. Upon UV illumination, the surface image became blurred with an apparent increased surface roughness. The image sharpened gradually as the surface returned to its initial state. This microstructural surface change is most pronounced at grain boundaries. © 2005 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jphotochem.2005.09.023

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  • Synthesis of high surface area Al-containing mesoporous silica from calcined and acid leached kaolinites as the precursors

    Chengala D. Madhusoodana, Yoshikazu Kameshima, Akira Nakajima, Kiyoshi Okada, Toshihiro Kogure, Kenneth J. D. MacKenzie

    JOURNAL OF COLLOID AND INTERFACE SCIENCE   297 ( 2 )   724 - 731   2006年5月

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    記述言語:英語   出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    Al-containing mesoporous silicas were synthesized by hydrothermal treatment of microporous silica prepared by selectively acid leached metakaolinites with Si/Al = 3.9-92.5 mixed with a surfactant of cetyltrimethylammonium bromide (CTABr). The Specific surface area of the products increased with higher surfactant/microporous silica (surf/Si) ratio and Si/Al ratio of the microporous silica. reaching about 1400 m(2)/g at CTABr/Si >= 0.1 and Si/Al >= 40. The XRD patterns of these products show a hexagonal (100) peak with the lattice parameter a(0) = 4.2-4.3 nm and the N-2 adsorption isotherms show steep increase of adsorption between relative pressure of 0.3 and 0.4. Hexagonal mesoporous microstructure is observed by high resolution TEM. The pore size distributions of the products Show a sharp peak at 2.8 nm by the BJH method. The high specific surface area of the present mesoporous samples is attributed to the lower matrix density and Surface roughness of mesopore wall. The highest specific surface area of the products reached LIP to 1420 m(2)/g and this value is apparently higher than those reported in hexagonal mesoporous silicas. A unique microporous structure of the starting material is thought to be related to achieve such a high specific surface area of the products. (c) 2005 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.jcis.2005.10.051

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  • Sliding acceleration of water droplets on a surface coated with fluoroalkylsilane and octadecyltrimethoxysilane

    S Suzuki, A Nakajima, M Sakai, JH Song, N Yoshida, Y Kameshima, K Okada

    SURFACE SCIENCE   600 ( 10 )   2214 - 2219   2006年5月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Both fluoroalkylsilane (FAS) and octadecyltrimethoxysilane (ODS) were coated on oxidized silicon wafers using soaking and CVD method. Smooth coatings with Ra values of less than 1 nm were attained. The slope of the sliding acceleration against the inverse of the droplet mass showed an inflection point. That point shifted to the direction of smaller droplets with decreasing FAS ratio to ODS. The water droplets' length was increased when the sliding velocity was increased. Fluoroalkylsilane addition to ODS increases the interaction between water and the hydrophobic surface. Results showed that the sliding acceleration of a water droplet depends strongly on the surface ratio of these silanes. (c) 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.susc.2006.03.015

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  • Direct observation of internal fluidity in a water droplet during sliding on hydrophobic surfaces

    M Sakai, JH Song, N Yoshida, S Suzuki, Y Kameshima, A Nakajima

    LANGMUIR   22 ( 11 )   4906 - 4909   2006年5月

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    記述言語:英語   出版者・発行元:AMER CHEMICAL SOC  

    In the current study, we used a high-speed camera system with particle image velocimetry to observe the internal fluidity of water droplets during sliding. The droplets' velocity during sliding was controlled by slipping and rolling motions. On the superhydrophobic surface, with a contact angle of 150, the droplet fell at high velocity by slipping. However, on a normal hydrophobic surface whose water contact angle was around 100, both slipping and rolling controlled the droplet's velocity during sliding. In addition, the advancing velocity might be large when the slip velocity is large and the contact area is small.

    DOI: 10.1021/la060323u

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  • Microwave-assisted hydrothermal synthesis of zeolite films on ceramic supports

    CD Madhusoodana, RN Das, Y Kameshima, K Okada

    JOURNAL OF MATERIALS SCIENCE   41 ( 5 )   1481 - 1487   2006年3月

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    記述言語:英語   出版者・発行元:SPRINGER  

    Zeolite films were formed on ceramic supports by a novel microwave-assisted hydrothermal method and were characterized by XRD, SEM, FTIR and BET surface area. The two-stage synthesis technique consists of microwave heating of supports saturated with precursor solution to form a thin layer of zeolite nano-seeds, followed by hydrothermal treatment to crystallize MFI zeolite. The resulting zeolite formation time was drastically reduced and the BET surface area of the product was double that obtained using conventional hydrothermal method. The dipping time, microwave heating time, power and hydrothermal heating time influence the amount of zeolite formation, the BET surface area and preferred orientation of the zeolite film. This new method of seed-film growth using a simple domestic microwave oven has the advantages of a two-stage synthesis technique, allowing independent control of nucleation and crystallization to obtain an optimum zeolite film and reduce the synthesis time. (c) 2006 Springer Science + Business Media, Inc.

    DOI: 10.1007/s10853-006-7490-y

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  • Solid acidity of 2 : 1 type clay minerals activated by selective leaching

    K Okada, N Arimitsu, Y Karneshima, A Nakajima, KJD MacKenzie

    APPLIED CLAY SCIENCE   31 ( 3-4 )   185 - 193   2006年3月

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    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Various 2: 1 type clay minerals were activated by H2SO4 treatment and their solid acidities were evaluated by NH3-temperature programmed desorption (TPD). Clay minerals with various degrees of Al substitution in the tetrahedral sheets were used as the starting materials. These included montmorillonite (ideally no tetrahedral Al), saponite (low content of tetrahedral Al), vermiculite (intermediate content of tetrahedral Al) and phlogopite (high tetrahedral Al content). All these samples showed increased solid acidity after selective leaching, the solid acidities varying in the order phlogopite < montmorillonite < vermiculite < saponite. The NE3-TPD spectra were deconvoluted into two peaks; the L-peak at < 200 degrees C corresponds to a weak acid site and the H-peak at > 250 degrees C corresponds to a strong acid site. The temperature of the H-peak was lowest in phlogopite (252 degrees C) and highest in saponite (305 degrees C). The generation of solid acidity in these samples is found to be related to the evolution of new tetrahedral Al sites showing a slightly different Al-27 MAS NMR chemical shift from the original tetrahedral Al NMR resonance. (c) 2005 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.clay.2005.10.014

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  • THz region dielectric properties of barium titanate fine particles using infrared reflection method

    S Wada, H Yasuno, T Hoshina, H Kakemoto, Y Kameshima, T Tsurumi, T Shimada

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   26 ( 10-11 )   1807 - 1810   2006年

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    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    The THz region dielectric properties of barium titanate (BaTiO3) fine particles were measured using the infrared (IR) reflection method. Prior to this measurement, to minimize the scattering light caused by surface roughness, the preparation of the dense 3D colloidal sphere arrays (colloidal crystals) with a flat surface was tried. First, the BaTiO3 fine particles were well dispersed into diethylene glycol as an organic solvent, and this BaTiO3 slurry was dried very slowly at 80 degrees C. Finally, the dense BaTiO3 colloidal crystals were successfully prepared. The IR reflection method was performed using these dense BaTiO3 colloidal crystals, and their IR reflection spectra were measured from 100 to 1200 cm(-1). As a result, by the use of the dense BaTiO3 colloidal crystals, the high intensity reflection spectra of the BaTiO3 fine particles were successfully obtained. The spectra were analyzed using a four-parameter semi-quantum (FPSQ) model, and finally, the THz region dielectric properties were estimated for the BaTiO3 fine particles. (c) 2005 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.jeurceramsoc.2005.09.091

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  • Extrusion method using nylon 66 fibers for the preparation of porous alumina ceramics with oriented pores

    T Isobe, Y Kameshima, A Nakajima, K Okada, Y Hotta

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   26 ( 12 )   2213 - 2217   2006年

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    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    Porous alumina ceramics with unidirectionally oriented pores were prepared using an extrusion method. The paste for extrusion was prepared by mixing alumina and nylon 66 fibers with binder and dispersant. The resulting paste was extruded, dried at room temperature, and after removal of the binder at 600 degrees C. fired at 1500 degrees C for 2 h. The pore size in the sintered body, determined from SEM micrographs, was 16 mu m, corresponding to the size of the burnt-out nylon 66 fibers. The degree of orientation of the cylindrical pores was evaluated from SEM micrographs to be highly aligned to the extrusion direction. The orientation of the pores decreased with increasing fiber loading because of strong interaction between the fibers. The pore size distribution of the extruded samples showed a peak at 16 mu m corresponding to the cylindrical pore diameter and also at 4 and 6 mu m corresponding to the pores formed by connection of the fibers. (c) 2005 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.jeuceramsoc.2005.04.014

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  • 分子軌道法による水-撥水表面の相互作用の解析

    亀島欣一

    (財)神奈川科学技術アカデミー(KAST) 平成17年度研究概要   87-90   2006年

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  • 微粒子・粉体の表面分析

    亀島 欣一

    日本セラミックス協会 原料部会講演会 講演要旨集   , , 1-8   2006年

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  • Multi functional uptake behaviour of materials prepared by calcining waste paper sludge

    VK Jha, Y Kameshima, A Nakajima, K Okada, KJD MacKenzie

    JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING   41 ( 4 )   703 - 719   2006年

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    記述言語:英語   出版者・発行元:TAYLOR & FRANCIS INC  

    This study concerns with the utilization of waste paper sludge, which contains mainly cellulose fibers and inorganic fillers together with coating materials such as calcite, kaolinite and talc. Paper sludge was fired at 500-900 degrees C for 6 h. The crystalline phases originally present decomposed at increasing temperatures (up to 800 degrees C) in the order kaolinite < calcite < talc. Gehlenite was formed at 800 degrees C in increasing amounts above this temperature together with small amounts of magnesium aluminum silicate and anorthite. The uptake of these fired samples of Ni2+, PO43- and NH4+ was investigated at room temperature. Paper sludge fired at 700 degrees C showed the highest uptake of Ni2+, PO43- and NH4+ (3.93, 1.28 and 0.49 mmol/g, respectively). The main process responsible for the sorption of these ions is the ion change along with precipitation with higher solution pH. From an economic point of view, paper sludge is the cheapest raw material for preparing adsorbents with high uptake ability for heavy metal, phosphate and ammonium ions.

    DOI: 10.1080/10934520600575101

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  • Biocompatibility of CaSiO3/high-density polyethylene composites prepared by hot-pressing

    M Tanuma, Y Kameshima, A Nakajima, K Okada, S Asai, M Sumita

    BIOCERAMICS 18, PTS 1 AND 2   309-311   1161 - 1164   2006年

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    記述言語:英語   出版者・発行元:TRANS TECH PUBLICATIONS LTD  

    We have reported that CaSiO3 ceramics show very fast bone-like apatite formation in simulated body fluid (SBF). However, CaSiO3 ceramics have disadvantages in their mechanical properties and shapability. It is therefore more effective to develop composites of CaSiO3 particles dispersed in a matrix of polymer or metal. Such composites are usually prepared by homogeneously blending the ceramic powder with the matrix component. This method is, however, ineffective for the preparation of biocompatible polymers or metals because only the surfaces containing accidentally-exposed ceramic particles play a role in generating apatite in SBF. It is therefore necessary to add a large volume of ceramic powder and also to abrade the surface to expose more of the ceramic particles. In this study, CaSiO3/high-density polyethylene (HDPE) composites were prepared by hot-pressing to introduce surface CaSiO3 particles and their biocompatibilities were evaluated under in vitro conditions using SBF. CaSiO3 powders were spread on a HDPE plate and hot-pressed at 140 degrees C and 4.9-14.7 MPa for 2 min. The composite sample (about 10x10x1 mm(3) in size) was immersed in 30ml SBF (sample/solution ratio of 2.5 g/l) at 36.5 degrees C. After 14 days soaking, the apatite product particles covered most of the composite surface and formed apatite layers. Bone-like apatite particles were formed only on the surface regions containing exposed CaSiO3 particles but no apatite was formed on the CaSiO3 particles buried in the HDPE matrix. The results show that this surface deposition method is very effective in developing biocompatibility in the composites using very small amounts of CaSiO3 powder (about < 1 %v) compared with results reported for hydroxyapatite and AW glass-ceramic powders (requiring about 40 %v). It is also found that the inhomogeneous state of the CaSiO3 particles in the surface of the present composites strongly influences their biocompatibility. It will be necessary to improve the homogeneity of CaSiO3 dispersion in the surface of the composites to achieve a more uniform surface apatite layer.

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  • Preparation and properties of porous alumina ceramics with oriented cylindrical pores produced by an extrusion method

    T Isobe, T Tomita, Y Kameshima, A Nakajima, K Okada

    JOURNAL OF THE EUROPEAN CERAMIC SOCIETY   26 ( 6 )   957 - 960   2006年

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    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    Porous alumina ceramics with unidirectionally-oriented pores were prepared by extrusion. Carbon fibers of 14 mu m diameter and 600 mu m length to be used as the pore-forming agent were kneaded with alumina, binder and dispersing agent. The resulting paste was extruded, dried at 100 degrees C, degreased at 1000 degrees C and fired at 1600 degrees C for 2 h. SEM showed a microstructure of dispersed highly oriented pores in a dense alumina matrix. The pore area in the cross section was 25.3% with about 1700 pores/mm(2). The pore size distribution of the fired body measured by Hg porosimetry showed a sharp peak corresponding to the diameter of the burnt-out carbon fibers. The resulting porous alumina ceramics with 38% total porosity showed a fracture strength of 171 MPa and a Young's modulus of 132 GPa. This strength is significantly higher than the reported value for other porous alumina ceramics even though the present pore size is much larger. (c) 2005 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.jeurceramsoc.2004.11.015

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  • Preparation and properties of glass-ceramics from kaolin clay refining waste (Kira) and paper sludge ash

    Tomohiro Toya, Yoshikazu Kameshima, Akira Nakajima, Kiyoshi Okada

    CERAMICS INTERNATIONAL   32 ( 7 )   789 - 796   2006年

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    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    Glass-ceramics were prepared from mixtures of wastes generated from refining of silica sand and kaolin clay (Kira) and paper sludge ash. Kira and paper sludge ash were mixed in mass ratios of 55/45. The mixtures were melted at 1400 degrees C and quenched in water to obtain glasses. The quenched glasses were ground to < 48 mesh and used to prepare glass-ceramics. Crystallization of the parent glass occurred above 950 degrees C, producing quartz solid solution at 1000 degrees C and cristobalite at 1100 degrees C as the major crystalline phases. The color of the glass-ceramics is white or slightly pale yellow. The four-point bending strengths of the as-fired glass-ceramics range from 63 to 66 MPa and the Vickers microhardness values from 6.0 to 6.4 GPa. The average linear thermal expansion coefficients of the glass-ceramics range from 6.3 x 10(-6) /degrees C to 8.1 x 10(-6) /degrees C (30-380 degrees C) and show non-linearity around the phase transition temperatures of quartz and cristobalite. The chemical durability of the resulting glass-ceramics is excellent in alkali but poor in acid solution. The glass-ceramics show rather better performance than commercial glass-ceramics even when prepared solely from wastes starting materials. (c) 2005 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

    DOI: 10.1016/j.ceramint.2005.06.008

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  • Preparation and Properties of Porous Alumina Ceramics with Oriented Pores

    T. Isobe, Y. Kameshima, A. Nakajima, K. Okada

    Key Eng. Mater.   2006年

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  • Preparation of ceramic honeycomb filter supported zeolite membrane modules by microwave-assisted in-situ crystallization

    C. D. Madhusoodana, R. N. Das, Y. Kameshima, K. Okada

    SCIENCE OF ENGINEERING CERAMICS III   317-318   697 - 700   2006年

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    記述言語:英語   出版者・発行元:TRANS TECH PUBLICATIONS LTD  

    Ceramic honeycomb filter supported zeolite membrane modules were prepared by a novel microwave-assisted in-situ crystallization method. The synthesis was done in two stages; microwave heating of substrates saturated with precursor solution to form a thin layer of zeolite nuclei (seeds) on the porous substrates followed by hydrothermal treatment to crystallize the ZSM-5 zeolite on the substrates. Zeolite formation was significantly enhanced by comparison with the conventional hydrothermal method, as evident from XRD and BET surface area results. The degree of film formation was varied with varying the dipping time of the substrates in the precursor solution prior to microwave heating, thereby controlling film formation inside the pores of the substrates. This new method of seeding using a simple domestic microwave oven was employed to zeolite membrane modules by forming a zeolite film on the thin walls of a honeycomb filter. The permeability of single gases and the separation of mixed gases were evaluated, showing a low pressure-drop and high permeating flux of light molecule gases.

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  • Preparation of Porous Silica from Chlorite by Selective Leaching

    K. OKADA, N. ARIMITSU, Y. KAMESHIMA, A. NAKAJIMA, K. J, D. MACKENZIE

    Applied clay science   30 ( 2 )   116 - 124   2005年

  • Reaction of Phosphate Compounds with A High-Silica Allophane

    K. Okada, K. Nishimuta, Y. Kameshima, A. Nakajima, K. J, D. MacKenzie

    Clays and Clay Minerals.   53 ( 4 )   372 - 379   2005年

  • Uptake properties of Ni2+ by nCaOAl2O32SiO2 (n=1-4) prepared from solid-state reaction of kaolinite and calcite

    V. K. Jha, Y. Kameshima, A. Nakajima, K. Okada, K. J, D. MacKenzie

    Journal of Hazardous Materials   123 ( 1-3 )   281 - 287   2005年

  • Effect of Roughness on Lipophobicity of a Surface Prepared using Boehmite Nanoparticles and Fluoroalkylsilane

    A. Nakajima, M. Hoshino, J-H. Song, Y. Kameshima, K. Okada

    Chem. Lett.   34 ( 7 )   908 - 909   2005年

  • Effect on uptake of heavy metal ions by phosphate grafting of allophane

    K. Okada, K. Nishimuta, Y. Kameshima, A. Nakajima

    J. Colloid Interface Sci.   286 ( 2 )   447 - 454   2005年

  • Preparation and Characterization of TiO2 Thin Films Using Vacuum Ultraviolet Light in a Sol-Gel Process

    Ken-ichi Katsumata, Akira Nakajima, Naoya Yoshida, Toshiya Watanabe, Yoshikazu Kameshima, Kiyoshi Okada

    Surface Science   596 ( 1-3 )   197 - 205   2005年

  • Photocatalytic Destruction of Gaseous Toluene by Sulfated TiO2 Powder

    A. Nakajima, H. Obata, Y. Kameshima, K. Okada

    Cat. Comm.   6 ( 11 )   716 - 720   2005年

  • Effect of Microstructure on Photoinduced Hydrophilicity of Transparent Anatase Thin Films

    Ken-ichi Katsumata, Akira Nakajima, Hidemi Yoshikawa, Tadashi Shiota, Naoya Yoshida, Toshiya Watanabe, Yoshikazu Kameshima, Kiyoshi Okada

    Surface Science   579 ( 2/3 )   123 - 130   2005年

  • Preparation and Properties of Carbon/Zeolite Composites with Corrugated Structure

    K. Okada, Y. Shimizu, Y. Kameshima, A. Nakajima

    J. Porus Mat.   12 ( 4 )   281 - 291   2005年

  • Alumina Coating on Stainless Steel Wire Net by Electrophoretic Deposition and its Oxidation Resistance

    F. Hasegawa, Y. Kameshima, A. Nakajima, K. Okada

    Trans. Mater. Res. Soc. Jpn.   29 ( 5 )   2265 - 2268   2004年

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  • Elongation and Contraction of Water Droplet during Sliding on the Silicon Surface Treated by Fluoroalkylsilane

    S. Suzuki, Y. Kameshima, A. Nakajima, K. Okada

    Surf. Sci.   557 ( 1/3 )   L163 - L168   2004年

  • Sonophotocatalytic Destruction of 1,4-Dioxane in Aqueous Systems by HF-treated TiO2 powder

    A. Nakajima, M. Tanaka, Y. Kameshima, K. Okada

    J. Photochem. Photobiol. A   167 ( 2/3 )   75 - 79   2004年

  • Hazardous Ions Uptake Behavior of Thermally Activated Steel Making Slag

    V. K. Jha, Y. Kameshima, A. Nakajima, K. Okada

    Journal of Hazardous Materials   114 ( 1-3 )   139 - 144   2004年

  • Sliding Mode Transition of Water Droplet on the Silicon Surface Coated with Octadecyltrichlorosilane

    A. Nakajima, S. Suzuki, Y. Kameshima, N, Yoshida T, Watanabe, K. Okada

    Chem. Lett   32 ( 12 )   1148 - 1149   2003年

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