Updated on 2022/01/15

写真a

 
UCHIDA Tetsuya
 
Organization
Faculty of Natural Science and Technology Associate Professor
Position
Associate Professor
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Degree

  • Dr.Eng. ( Okayama University )

Research Interests

  • 複合体

  • 固体構造

  • 人工網膜

  • カーボンナノチューブ

  • 高分子単結晶

  • 結晶化

  • 高分子

  • Polymer

  • Structure

  • Crystal

Research Areas

  • Nanotechnology/Materials / Composite materials and interfaces

  • Nanotechnology/Materials / Polymer materials

  • Life Science / Biomaterials  / 人工網膜

Education

  • Okayama University   工学研究科   精密応用化学専攻

    1992 - 1994

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    Country: Japan

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  • Okayama University   工学部   精密応用化学科

    1988 - 1992

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    Country: Japan

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Research History

  • 岡山大学学術研究院 自然科学学域   研究教授

    2021.10

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  • - Associate Professor,Graduate School of Natural Science and Technology,Okayama University

    2012

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  • - 岡山大学自然科学研究科 准教授

    2012

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  • 岡山大学自然科学研究科機能分子化学専攻 講師

    2007 - 2012

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  • Senior Assistant Professor,Chemistry and Biochemistry,Graduate School of Natural Science and Technology,Okayama University

    2007 - 2012

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  • 米国 ジョージア工科大学 客員研究員

    2002 - 2003

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Professional Memberships

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Committee Memberships

  • Asian Textile Conference(ATC-16)   Secretary General  

    2020.4   

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  • 晴れの国CNF連絡会   アドバイザー  

    2020.4   

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    Committee type:Municipal

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  • おかやま自動車要素技術共創コンソーシアム (ACCEL)   幹事  

    2020.4   

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    Committee type:Municipal

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  • 繊維学会関西支部   幹事  

    2020.4   

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  •   Journal of Fiber Science and Technology 編集委員  

    2019.1   

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  •   岡山地区高分子懇話会 会長  

    2015.1   

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  • 日本材料学会中国支部   幹事  

    2011.4   

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Papers

  • Clarification of degradation mechanism on retinal prosthesis using photoelectric dyes coupled to polyethylene film by mass spectrometry Reviewed

    Koichiro Yamashita, Mayu Mitsui, Toshihiko Matsuo, Tetsuya Uchida

    Materials Letters   307   130978 - 130978   2022.1

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.matlet.2021.130978

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  • Modelling the visual response to an OUReP retinal prosthesis with photoelectric dye coupled to polyethylene film Reviewed

    Koichiro Yamashita, Prathima Sundaram, Tetsuya Uchida, Toshihiko Matsuo, Willy Wong

    JOURNAL OF NEURAL ENGINEERING   18 ( 4 )   2021.8

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    Objective. Retinal prostheses have been developed to restore vision in blind patients suffering from diseases like retinitis pigmentosa. Approach. A new type of retinal prosthesis called the Okayama University-type retinal prosthesis (OUReP) was developed by chemically coupling photoelectric dyes to a polyethylene film surface. The prosthesis works by passively generating an electric potential when stimulated by light. However, the neurophysiological mechanism of how OUReP stimulates the degenerated retina is unknown. Main results. Here, we explore how the OUReP affects retinal tissues using a finite element model to solve for the potential inside the tissue and an active Hodgkin-Huxley model based on rat vision to predict the corresponding retinal bipolar response. Significance. We show that the OUReP is likely capable of eliciting responses in retinal bipolar cells necessary to generate vision under most ambient conditions.

    DOI: 10.1088/1741-2552/abf892

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  • Development of highly durable retinal prosthesis using photoelectric dyes coupled to polyethylene film and quantitative in vitro evaluation of its durability Reviewed

    Koichiro Yamashita, Tenu Tanaka, Toshihiko Matsuo, Tetsuya Uchida

    BIOMEDICAL MATERIALS   16 ( 4 )   2021.7

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    Retinal prostheses have been developed to restore vision in blind patients suffering from such diseases as retinitis pigmentosa. In our previous studies, we developed a retinal prosthesis called dye-coupled film by chemical coupling of photoelectric dyes, which absorb light and then generate electrical potential, with a polyethylene film surface. The dye-coupled film is nontoxic, and we recovered the vision of a monkey with macular degeneration. The amount of dye on the dye-coupled film, however, decreased to one-third after five months in the monkey's eye. The photoelectric dye consists of a cation with photoresponsivity and a bromide ion (Br-). Therefore, an anion-exchange reaction could be applied to the dye-coupled film to improve its durability. In this study, the anion-exchange reaction was conducted using bis(trifluoromethanesulfonyl)imide ion (TFSI-), which has lower nucleophilicity than Br-. First, the long-term durability was examined without using animal subjects and in a short period. Subsequently, an elemental analysis was performed to confirm the exchange between Br- and TFSI-, and chemical properties, such as photoresponsivity and durability, before and after the anion exchange, were evaluated. It was quantitatively confirmed that the long-term durability of dye-coupled films can be evaluated in an in vitro environment and in a short period of one-thirtieth by utilizing a saline solution at 60 degrees C, compared with an in vivo environment. In addition, the durability of the dye-coupled film with TFSI- was improved to 270%-320% compared with that of the dye-coupled film with Br-.

    DOI: 10.1088/1748-605X/abe809

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  • Development and chemical properties of retinal prostheses using photoelectric dyes coupled to polyethylene films with various anions to achieve high durability Reviewed

    Koichiro Yamashita, Tenu Tanaka, Toshihiko Matsuo, Tetsuya Uchida

    POLYMER JOURNAL   53 ( 6 )   719 - 729   2021.6

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:SPRINGERNATURE  

    Photoelectric dyes, which absorb light and generate electric potential, have been shown to stimulate retinal neurons. Therefore, in the present work, a photoelectric dye was used to develop a retinal prosthesis to restore vision loss due to diseases, such as retinitis pigmentosa. The retinal prosthesis, referred to as a dye-coupled film, was prepared by chemically coupling the dyes to a polyethylene film surface. However, the amount of coupled dye decreased during an implantation test in a monkey's eye. The dye consisted of a cation with photoresponsivity and Br-. Because thermal stability can be improved by anion exchange, we expected anion exchange to lead to stabilization of the chemical structure, resulting in improvement of the long-term durability of a retinal prosthesis. Therefore, the effects of exchanging Br- anions for PF6-, BF4-, and bis(trifluoromethanesulfonyl)imide (TFSI-) anions on the durability were investigated. The long-term durability of the dye-coupled films was found to be strongly related to the thermal stability of the photoelectric dye. The long-term durability of the dye-coupled film-PF6- and dye-coupled film-TFSI- improved by 637 and 215%, respectively, compared with that of the dye-coupled film-Br-.

    DOI: 10.1038/s41428-021-00468-0

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  • Photoelectric dye, NK-5962, as a potential drug for preventing retinal neurons from apoptosis: pharmacokinetic studies based on review of the evidence Reviewed

    Toshihiko Matsuo, Tetsuya Uchida, Shihui Liu, Satomi Onoue, Shinsaku Nakagawa, Mayumi Ishii, Kayoko Kanamitsu

    Life   11   591   2021.6

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  • Crystallization of single-walled carbon nanotubes from a dilute solution Reviewed

    Tetsuya Uchida, Naoya Tsugawa, Satoru Yoshida, Natsuki Tohnai

    POLYMER   216   2021.2

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    Single-walled carbon nanotubes (SWNTs) with lengths of several hundred nanometers were crystallized from dilute solutions, and slender lath-shaped SWNT crystals were obtained. The SWNTs were oriented along the long axis of the lath-shaped crystal, and the obtained crystals were two-dimensional crystals comprising hexagonally close-packed SWNTs. A relatively long SWNT acted as a crystalline nucleus. The length of the SWNT used for crystallization affected the morphology and growth rate of the crystals. Higher crystallization temperature shortened the time to precipitation, and the diffusion of SWNTs dominated the crystal growth of SWNT crystals. Because the short SWNTs were rigid with a wide length distribution, their tube ends were inevitably included in the crystals, resulting in crystal defects, such as lattice curvature and edge dislocations. These defects were directly observed by high-resolution electron microscopy. The mechanism for the crystallization of the SWNTs was proposed based on the observed morphologies, crystal defects, and crystallization process.

    DOI: 10.1016/j.polymer.2021.123425

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  • Preparation of highly porous heat-resistant polybenzoxazole network films and their electrical conductivities

    Uchida, T., Onishi, Y., Goto, A.

    Polymers for Advanced Technologies   2021

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    DOI: 10.1002/pat.5494

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  • Preparation of solution-grown lozenge-shaped poly(p-phenylene terephthalamide) single crystals and their structural stabilization by heat treatment Reviewed

    Tetsuya Uchida, Yutaro Hara, Tomoyasu Takaki

    POLYMER   202   2020.8

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    In this study, the preparation of poly (p-phenylene terephthalamide) (PPTA) single crystals was examined using crystallization from dilute solutions in concentrated sulfuric acid. Lozenge-shaped PPTA single crystals were successfully prepared using a self-seeding method with a low degree of supercooling, and they consisted of modification I crystals. The a-axis direction of the crystal corresponded to the long diagonal direction of the rhombus, the b-axis direction with the short diagonal direction, and the PPTA molecular chain direction (the c-axis direction) with the crystal's thickness direction. In addition, the PPTA single crystals had a (110) growth plane, where the thickness of each single crystal was approximately equal to the molecular chain length of the PPTA. Upon heat treatment of the PPTA single crystals, the symmetry changed from P1a1 to the more stable P11n. In addition, the heat treatment caused a difference in the density of each symmetric crystal, resulting in crack formation along the b-axis direction, which is the hydrogen-bonding direction. However, the heat treatment did not change the thickness of the PPTA single crystals. Conversely, the isothermal crystallization of the PPTA caused progression in the crystallization only under a high degree of supercooling, thus yielding plate-like PPTA crystals that consisted of modification II crystals. In these plate-like PPTA crystals, the length corresponded to the crystal a-axis direction, and the electron diffraction pattern was broad. Furthermore, the equilibrium dissolution temperature of the PPTA single crystals was discussed.

    DOI: 10.1016/j.polymer.2020.122672

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  • Curved-Tip Disposable Injector (OUReP Injector) to Insert Photoelectric Dye-Coupled Polyethylene Film (OUReP) as Retinal Prosthesis into Subretinal Space of Rabbit Eyes Reviewed

    Toshihiko Matsuo, Chie Matsuo, Tetsuya Uchida, Koichiro Yamashita, Tenu Tanaka, Yusuke Kawakami, Toshiya Hitomi, Kanji Taga, Tatsuya Sanada, Yusuke Yamashita

    Journal of Surgical Techniques and Procedures   4   1040   2020.7

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  • Step-by-Step Procedure to Test Photoelectric Dye-Coupled Polyethylene Film as Retinal Prosthesis to Induce Light-Evoked Spikes in Isolated Retinal Dystrophic Tissue of rd1 Mice Reviewed

    Toshihiko Matsuo, Keiko Terada, Mikako Sakurai, Shihui Liu, Koichiro Yamashita, Tetsuya Uchida

    Clinics in Surgery   5   2903   2020.5

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  • Vision evaluation by functional observational battery, operant behavior test, and light/dark box test in retinal dystrophic RCS rats versus normal rats Reviewed

    Toshihiko Matsuo, Tetsuya Uchida, Koichiro Yamashita, Shigiko Takei, Daisuke Ido, Atsushi Fujiwara, Masahiko Iino, Masao Oguchi

    HELIYON   5 ( 6 )   2019.6

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    Background: Vision plays a key role in some behavior tests for rats. Okayama University-type retinal prosthesis (OUReP) is a photoelectric dye-coupled polyethylene film which generates electric potential in response to light and stimulates nearby neurons. This study aims to assess vision in retinal dystrophic (RCS) rats, in comparison with normal rats, by selected behavior tests. We also examined whether the tests could detect vision changes in RCS rats with dye-coupled film implantation.Methods: Data sets were 5 normal rats, 4 untreated RCS rats, 7 RCS rats with dye-coupled films implanted at the age of 7 weeks after excluding unsuccessful implantation at autopsy. Behavior tests chosen were landing foot splay and visual forelimb-placing response in the menu of functional observational battery, operant-conditioning lever-press response and light/dark box test.Results: Normal visual placing response was significantly less frequent in untreated RCS rats at the age of 9 and 11 weeks, compared with normal rats (P = 0.0027, chi-square test) while normal response was significantly more frequent at the age of 9 weeks in RCS rats with dye-coupled film implantation, compared with untreated RCS rats (P = 0.0221). In operant-conditioning lever-press test, the correct response rate was significantly lower in untreated RCS rats than in normal rats at the age of 9 weeks (P < 0.05, Tukey-Kramer test) while the rate was not significantly different between normal rats and RCS rats with dye-coupled film implantation. In light/dark box test, the time to enter dark box was significantly shorter in normal rats, compared with untreated RCS rats or RCS rats with dye-coupled film implantation (P < 0.05, Tukey-Kramer test).Conclusions: Behavior tests of functional observational battery, operant-conditioning lever-press response and light/dark box test discriminated vision between normal rats and RCS rats. The visual placing response and operant-conditioning lever-press test might have sensitivity to detect vision recovery in RCS rats with OUReP implantation.

    DOI: 10.1016/j.heliyon.2019.e01936

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  • Photoelectric Dye-Coupled Polyethylene Film: Photoresponsive Properties Evaluated by Kelvin Probe and In Vitro Biological Response Detected in Dystrophic Retinal Tissue of Rats Reviewed

    Toshihiko Matsuo, Mikako Sakurai, Keiko Terada, Tetsuya Uchida, Koichiro Yamashita, Tenu Tanaka, Kenichi Takarabe

    ADVANCED BIOMEDICAL ENGINEERING   8   137 - 144   2019

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPANESE SOC MEDICAL & BIOLOGICAL ENGINEERING  

    Electrodes that output electric current as conduction current are widely used to stimulate nerves and cardiac cells in human body. We designed a photoelectric dye-coupled polyethylene film for use as a thin film device to stimulate nerve cells by electric potential changes. The aim of this study was to measure its photo-responsive properties and to record in vitro biological response. When measured using a Kelvin probe system, the photoelectric dye-coupled film showed rapid rise and fall of surface electric potential in response to light-on-and-off. Light-evoked surface electric potential of the dye-coupled film increased in response to increasing light intensity. In vitro biological response to the dye-coupled film was assessed in isolated rat retinal tissues using a multielectrode array recording system. As positive control, electroretinogram-like waves were recorded in response to light from normal rat retinal tissue placed with the inner retinal surface at the bottom of the multielectrode array dish. In contrast, no light-elicited wave was recorded from degenerative retinal tissue isolated from retinal dystrophic Royal College of Surgeons (RCS) rats. When the dye-coupled film was simply overlaid on the degenerative retinal tissue with the inner retinal surface placed at the bottom of the multielectrode array dish, electroretinogram-like waves were elicited in response to light projected from the bottom. Plain polyethylene film without photoelectric dye coupling was used as negative control, and did not yield light-elicited response when placed on the degenerative retinal tissue. For detailed recordings of action potential spikes high-passed at 100 Hz, a nylon mesh anchor was placed on top of the preparation to ensure close contact between the multielectrode array and the retinal tissue with or without the dye-coupled film. In this experimental setting, the degenerative retinal tissue alone showed spontaneous action potential spikes as numerous small trivial amplitudes in the background noise, while the degenerative retinal tissue overlain with the dye-coupled film showed action potential spikes with increased amplitude in response to light against the background of spontaneous spikes. This study confirmed that the photoelectric dye-coupled polyethylene film is able to stimulate degenerative retinal tissue that has lost photoreceptor cells, and may function as a novel type of retinal prosthesis. Electric potential changes, probably as displacement current or capacitive current, may be an alternative approach to stimulate nerves in human body.

    DOI: 10.14326/abe.8.137

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  • Development of High-Performance Nanofibers by Using Crystallization from Dilute Solution and Their Application in Composites

    Tetsuya Uchida

    SEN-I GAKKAISHI   74 ( 10 )   P489 - P492   2018.10

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:SOC FIBER SCIENCE TECHNOLOGY  

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  • Visual Evoked Potential Recovery by Subretinal Implantation of Photoelectric Dye-Coupled Thin Film Retinal Prosthesis in Monkey Eyes With Macular Degeneration Reviewed

    Toshihiko Matsuo, Tetsuya Uchida, Jun Sakurai, Koichiro Yamashita, Chie Matsuo, Tomoaki Araki, Yusuke Yamashita, Kunihisa Kamikawa

    ARTIFICIAL ORGANS   42 ( 8 )   E186 - E203   2018.8

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:WILEY  

    Retinal prosthesis or artificial retina is a promising modality of treatment for outer retinal degeneration, caused by primary and secondary loss of photoreceptor cells, in hereditary retinal dystrophy and age-related macular degeneration, respectively. Okayama University-type retinal prosthesis (OUReP) is a photoelectric dye-coupled polyethylene film which generates electric potential in response to light and stimulates nearby neurons. The dyecoupled films were implanted by vitreous surgery in the subretinal space of monkey eyes with macular degeneration which had been induced by cobalt chloride injection from the scleral side. A pilot 1-month observation study involved 6 monkeys and a pivotal 6-month observation study involved 8 monkeys. Of 8 monkeys in 6-month group, 3 monkeys underwent dye-coupled film removal at 5 months and were observed further for 1 month. The amplitude of visual evoked potential which had been reduced by macular degeneration did recover at 1 month after film implantation and maintained the level at 6 months. Optical coherence tomography showed no retinal detachment, and full-field electroretinograms maintained a-wave and b-wave amplitudes, indicative of no retinal toxicity. Pathological examinations after 6-month implantation showed structural integrity of the inner retinal layer in close apposition to dye-coupled films. The implanted films which were removed by vitrectomy 5 months later showed light-evoked surface electric potentials by scanning Kelvin probe measurement. The photoelectric dye-coupled film (OUReP), which serves as a light-receiver and a displacement current generator in the subretinal space of the eye, has a potential for recovering vision in diseases with photoreceptor cell loss, such as retinitis pigmentosa and age-related macular degeneration.

    DOI: 10.1111/aor.13120

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  • Novel disposable injector (OUReP Injector) tested in rabbits’ eyes for subretinal implantation of Okayama University-type retinal prosthesis (OUReP) Reviewed

    T.Matsuo, T.Uchida, K.Yamashita, C.Matsuo, Y.Kawakami, T.Hitomi, K.Taga, T.Sanada, Y.Yamashita, K.Kuramoto

    Anim. Eye Res.   37   3 - 12   2018.7

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  • Visual evoked potential in rabbits' eyes with subretinal implantation by vitrectomy of Okayama University-type retinal prosthesis (OUReP (TM)) Reviewed

    Toshihiko Matsuo, Tetsuya Uchida, Koichiro Yamashita, Shigiko Takei, Daisuke Ido, Mamoru Tanaka, Masao Oguchi, Toshinori Furukawa

    JOURNAL OF VETERINARY MEDICAL SCIENCE   80 ( 2 )   247 - 259   2018.2

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JAPAN SOC VET SCI  

    Okayama University-type retinal prosthesis (OURePTM) is a photoelectric dye-coupled polyethylene film which generates electric potential in response to light and stimulates nearby neurons. This study aims to test surgical feasibility for subretinal film implantation and to examine functional durability of films in subretinal space. Dye-coupled films were implanted subretinally by vitrectomy in the right eye of normal white rabbits: 8 rabbits for 1 month and 8 rabbits for 6 months. The implanted films were removed by vitrectomy in 4 of these 8 rabbits in 1-month or 6-month implantation group. The films were also implanted in 4 rhodopsin-transgenic retinal dystrophic rabbits. Visual evoked potential was measured before film implantation as well as 1 or 6 months after film implantation, or 1 month after film removal. The films were successfully implanted in subretinal space of retinal detachment induced by subretinal fluid injection with a 38G polyimide tip. The retina was reattached by fluid-air exchange in vitreous cavity, retinal laser coagulation, and silicone oil injection. The ratios of P-2 amplitudes of visual evoked potential in the implanted right eye over control left eye did not show significant changes between pre-implantation and post-implantation or post-removal (paired t-test). In Kelvin probe measurements, 4 pieces each of removed films which were implanted for 1 or 6 months showed proportional increase of surface electric potential in response to increasing light intensity. The film implantation was safe and implanted films were capable of responding to light.

    DOI: 10.1292/jvms.17-0422

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  • Amino group in Leptothrix sheath skeleton is responsible for direct deposition of Fe(III) minerals onto the sheaths Reviewed

    Tatsuki Kunoh, Syuji Matsumoto, Noriyuki Nagaoka, Shoko Kanashima, Katsuhiko Hino, Tetsuya Uchida, Katsunori Tamura, Hitoshi Kunoh, Jun Takada

    SCIENTIFIC REPORTS   7 ( 1 )   141 - 149   2017.7

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:NATURE PUBLISHING GROUP  

    Leptothrix species produce microtubular organic-inorganic materials that encase the bacterial cells. The skeleton of an immature sheath, consisting of organic exopolymer fibrils of bacterial origin, is formed first, then the sheath becomes encrusted with inorganic material. Functional carboxyl groups of polysaccharides in these fibrils are considered to attract and bind metal cations, including Fe(III) and Fe(III)-mineral phases onto the fibrils, but the detailed mechanism remains elusive. Here we show that NH2 of the amino-sugar-enriched exopolymer fibrils is involved in interactions with abiotically generated Fe(III) minerals. NH2-specific staining of L. cholodnii OUMS1 detected a terminal NH2 on its sheath skeleton. Masking NH2 with specific reagents abrogated deposition of Fe(III) minerals onto fibrils. Fe(III) minerals were adsorbed on chitosan and NH2-coated polystyrene beads but not on cellulose and beads coated with an acetamide group. X-ray photoelectron spectroscopy at the N1s edge revealed that the terminal NH2 of OUMS1 sheaths, chitosan and NH2-coated beads binds to Fe(III)-mineral phases, indicating interaction between the Fe(III) minerals and terminal NH2. Thus, the terminal NH2 in the exopolymer fibrils seems critical for Fe encrustation of Leptothrix sheaths. These insights should inform artificial synthesis of highly reactive NH2-rich polymers for use as absorbents, catalysts and so on.

    DOI: 10.1038/s41598-017-06644-8

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  • Visual evoked potential in RCS rats with Okayama University-type retinal prosthesis (OUReP (TM)) implantation Reviewed

    Alamusi, Toshihiko Matsuo, Osamu Hosoya, Tetsuya Uchida

    JOURNAL OF ARTIFICIAL ORGANS   20 ( 2 )   158 - 165   2017.6

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:SPRINGER JAPAN KK  

    Photoelectric dye-coupled polyethylene film, designated Okayama University type-retinal prosthesis or OUReP (TM), generates light-evoked surface electric potentials and stimulates neurons. The dye-coupled films or plain films were implanted subretinally in both eyes of 10 Royal College of Surgeons rats with hereditary retinal dystrophy at the age of 6 weeks. Visual evoked potentials in response to monocular flashing light stimuli were recorded from cranially-fixed electrodes, 4 weeks and 8 weeks after the implantation. After the recording, subretinal film implantation was confirmed histologically in 7 eyes with dye-coupled films and 7 eyes with plain films. The recordings from these 7 eyes in each group were used for statistical analysis. The amplitudes of visual evoked potentials in the consecutive time points from 125 to 250 ms after flash were significantly larger in the 7 eyes with dye-coupled film implantation, compared to the 7 eyes with plain film implantation at 8 weeks after the implantation (P < 0.05, repeated-measure ANOVA). The photoelectric dye-coupled polyethylene film, as retinal prosthesis, gave rise to visual evoked potential in response to flashing light.

    DOI: 10.1007/s10047-016-0943-4

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  • Photoelectric Dye Used for Okayama University-Type Retinal Prosthesis Reduces the Apoptosis of Photoreceptor Cells Reviewed

    Shihui Liu, Toshihiko Matsuo, Osamu Hosoya, Tetsuya Uchida

    JOURNAL OF OCULAR PHARMACOLOGY AND THERAPEUTICS   33 ( 3 )   149 - 160   2017.4

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:MARY ANN LIEBERT, INC  

    Purpose: Our previous study demonstrated that photoelectric dye-coupled polyethylene film (Okayama University-type retinal prosthesis), which was implanted in subretinal space of the eyes of Royal College of Surgeons (RCS) rats, prevented retinal neurons from apoptotic death. In this study, we aimed to examine whether photoelectric dye itself would protect retinal neurons from apoptosis in RCS rats.Methods: RCS rats received intravitreous injection of different concentrations of the dye in the left eye and housed under a 12-h light-dark cycle. Saline injection in the right eye served as control. In addition, RCS rats with dye injection were kept in 24-h daily dark condition. Sections were processed for terminal deoxynucleotidyl transferase-mediated fluorescein-conjugated-dUTP nick-end-labeling (TUNEL) assay and immunohistochemical staining of glial fibrillary acidic protein (GFAP) and protein kinase C alpha (PKC alpha).Results: The number of TUNEL-positive cells significantly decreased in the retina of dye-injected eyes compared with those in saline-injected eyes (P = 0.0001, 2-factor analysis of variance [ANOVA]), under 12-h light-dark cycle. Significant decrease of TUNEL-positive cells was noted in the retina of rats with dye injection compared with those with saline injection, kept under 24-h dark condition (P = 0.0001, 2-factor ANOVA). Immunoreactive area for GFAP decreased significantly in the retina of dye-injected eyes compared with that in controls (P = 0.0001, 2-factor ANOVA), whereas immunoreactive area for PKCa increased significantly in the retina of dye-injected eyes compared with that in controls (P = 0.01, 2-factor ANOVA).Conclusions: Photoelectric dye inhibits apoptotic death of photoreceptor cells in RCS rats and downregulates GFAP expression in retinal Muller cells. Photoelectric dye may be a candidate agent for neuroprotection in retinitis pigmentosa and other retinal diseases.

    DOI: 10.1089/jop.2016.0093

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  • Size control of aromatic polyamide hollow spheres prepared by reaction-induced phase separation Reviewed

    Hirofumi Nakayama, Naoto Adachi, Hironori Atarashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    POLYMER   111   239 - 243   2017.2

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCI LTD  

    Size control of the poly (1,4-phenylene-5-hydroxyisophthalamide) hollow spheres was examined by tuning the polymerization condition, focusing on concentration, temperature and solvent. Higher concentration lowered the diameter owing to the higher degree of super-saturation for nucleation. Temperature drop during the polymerization just before the nucleation was so effective to make the diameter smaller. Moreover, the diameter was susceptive to the solubility of oligomers in the solvent, and higher content of liquid paraffin in the aromatic solvent lowered the solubility, resulting in the decrease in the diameter. Based on these results, the combination of the temperature drop and the solvent effect was the most desirable to prepare the smallest hollow spheres, and the diameter of hollow spheres could be controlled from 4.4 to 0.7 mu m. (C) 2017 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.polymer.2017.01.060

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  • Subretinal implantation of Okayama University-type retinal prosthesis (OUReP (TM)) in canine eyes by vitrectomy Reviewed

    Toshihiko Matsuo, Tetsuya Uchida, Makoto Nitta, Koichiro Yamashita, Shigiko Takei, Daisuke Ido, Mamoru Tanaka, Masao Oguchi, Toshinori Furukawa

    JOURNAL OF VETERINARY MEDICAL SCIENCE   79 ( 12 )   1939 - 1946   2017

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    Okayama University-type retinal prosthesis (OUReP (TM)) is a photoelectric dye-coupled polyethylene film which generates electric potential in response to light and stimulates nearby neurons. This study aims to test surgical feasibility of subretinal implantation and functional durability of dye-coupled films in the subretinal space. The dye-coupled films were implanted subretinally by 25-gauge vitrectomy in the right eye of 11 normal beagle dogs: 2 dogs served for film removal after 5-month film implantation, 3 dogs for film removal after 3-month film implantation, 3 dogs for 3-month film implantation and pathological examination, and 3 dogs for sham surgery. The surface electric potential of the removed dye-coupled films in response to light was measured by the Kelvin Probe system. At surgery, rolled-up dye-coupled films in 5 x 5 mm square size could be inserted into subretinal space of retinal detachment induced by fluid injection with a 38-gauge polyimide tip. Retinal attachment was maintained by silicone oil injection in vitreous cavity. At autopsy, the retina in all dogs maintained the ganglion cell layer, inner and outer nuclear layers while it lost the outer segments in some part. All 5 sheets of removed dye-coupled films maintained the dye color. One sheet of the 5-month implanted film showed proportional increase of surface potential in response to increasing light intensity. Subretinal implantation of OUReP (TM) by vitrectomy was technically feasible in canine eyes, and OUReP (TM) maintained the function of generating light-evoked surface potential after 5 months in subretinal implantation.

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  • Preparation of cellulose nanofibers coated with poly(vinyl alcohol) crystals and their application in composite films Reviewed

    Tetsuya Uchida, Fumiaki Iwaguro, Risa Yanai, Haruka Dodo

    RSC ADVANCES   7 ( 32 )   19828 - 19832   2017

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    Poly(vinyl alcohol) (PVA) was crystallized from a dilute solution in the presence of cellulose nanofibers (CeNFs). The CeNFs acted as nucleating agents for PVA crystallization, and PVA crystals were grown on the CeNFs' surface. As a result, CeNFs coated with PVA crystals (CeNF/PVA nanocomposite fiber (NCF(CeNF/PVA))) were successfully obtained. The NCF(CeNF/PVA) showed good dispersibility in water even after drying. Composite films were prepared using the aforementioned NCF(CeNF/PVA) and their mechanical properties were measured. Despite the low content of NCF(CeNF/PVA=1/5) (0.1 wt%, corresponding to 1.7 x 10(-2) wt% CeNF), the mechanical properties of the composite films improved in comparison to those of the control samples. This reinforcement effect of the NCF(CeNF/PVA=1/5) was greater than that of pure CeNFs. Surface modification of the NCF was also discussed, and the surface hydrophilicity of the NCF could be controlled depending on the choice of coating crystal.

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  • Crystallization from Dilute Solution of Poly(p-Phenylene Benzobisthiazole) (PBZT) in the Presence of Carbon Nanotubes Reviewed

    Tetsuya Uchida, Atsushi Mishima, Takayuki Ikeda, Masashi Furukawa, Koji Asanuma

    JOURNAL OF FIBER SCIENCE AND TECHNOLOGY   73 ( 1 )   1 - 7   2017

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    Poly(p-phenylene benzobisthiazole) (PBZT) Was crystallized from dilute solution in the presence of single-wall carbon nanotube (SWNT) or multi-wall carbon nanotube (MWNT). In this crystallisation condition, SWNT existed as pristine bundles. SWNT bundles and MWNT acted as nucleating agents of PBZT crystallisation.The nucleating effect of the SWNT bundle was larger than that of MWNT. Transmission electron microscope observation revealed that the morphology of the PBZT crystal on the carbon nanotube (CNT) could be controlled by crystallization condition such as molecular length of PBZT, H2SO4 concentration, variety of CNT. Thermal stability of PBZT crystallized on SWNT bundles was discussed by the observation of crystal dissolution temperature.

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  • Apoptosis reduction by a photoelectric dye used for Okayama University-type retinal prosthesis (OUReP (TM))

    Shihui Liu, Toshihiko Matsuo, Osamu Hosoya, Tetsuya Uchida

    INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE   57 ( 12 )   2016.9

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  • Preparation of helical crystals of aromatic poly(ester-imide) and on-off switching of helix formation Reviewed

    Takuya Ohnishi, Miki Nakagawa, Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    POLYMER   98   378 - 386   2016.8

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    Preparation of poly[4-(5-oxy-1,3-dioxoisoindoline-2-yl)benzoyl] (PODB) crystals, which was an intractable aromatic poly(ester-imide), was examined by means of reaction-induced crystallization of oligomers during the polymerization. Highly crystalline PODB helical ribbons were obtained by the polymerization of N-(4-carboxyphenyl)-4-acetoxyphthalimide in aromatic solvent at 280-330 degrees C at a concentration of 0.5-1.0%. The PODB molecules aligned along the long axis of the helical ribbon. The pitch of the helix increased with the polymerization temperature and it could be controlled from 320 nm to 1.3 mu m. Further, the fibrillar PODB crystals comprised of the helical and the non-helical blocks were prepared by the on-off switching of the helical morphology with the changing the temperature and the concentration of the polymerization. These results provided the methodology for the morphology control of polymer crystals. (C) 2016 Elsevier Ltd. All rights reserved.

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  • Preparation of poly(ester-imide) ribbons comprised of helical and non-helical blocks by copolymerization Reviewed

    T. Ohnishi, T. Uchida, S. Yamazaki, K. Kimura

    RSC ADVANCES   6 ( 104 )   101995 - 102002   2016

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    Helical ribbons of poly[4-(5-oxy-1,3-dioxoisoindoline-2-yl) benzoyl] (PODB) were previously prepared by the homo-polymerization of N-(4-carboxyphenyl)-4-acetoxyphthalimide (CAP) in aromatic solvents. The copolymerization of CAP and p-acetoxybenzoic acid (ABA) was examined to change the helical morphology. The helical morphology was extinguished by the copolymerization of a small amount of ABA at 280 degrees C at a concentration of 1.0% in aromatic solvent. Based on these results, ABA was added stepwise during the homo-polymerization of CAP. When a small amount of ABA was added, copolymer crystals comprised of helical and non-helical blocks were formed. The non-helical blocks grew on the PODB helical ribbons by the precipitation of co-oligomers. This result provides a novel method to control helical morphology by copolymerization.

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  • Consideration on formation mechanism of aromatic polyamide hollow spheres prepared by reaction-Induced phase separation Reviewed

    Hirofumi Nakayama, Yuji Fujitsu, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   53 ( 17 )   1966 - 1974   2015.9

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    Hollow spheres of poly(1,4-phenylene-5-hydroxyisophthalamide) had been obtained by the reaction-induced phase separation during polymerization of 5-hydroxyisophthalic acid and 1,4-phenylene diamine in an aromatic solvent. In this study, formation mechanism of the hollow spheres was considered from the view points of eliminated small molecules, polymer structure, and cross-linking reaction. With respect to the eliminated small molecules, water was the most desirable to form gas-bubbles in droplets compared with methanol and acetic acid, due to the insolubility into the polymerization system. Rigid polymer structure was also needed to prepare hollow spheres owing to the rapid solidification of droplets. Further, phenolic hydroxyl group in 5-hydroxy-1,3-phenylene moiety caused the ester-amide exchange reaction to form cross-linked skin layer in the droplets. The efficient formation of the skin layer was important to encapsulate gas-bubbles in the droplets, resulting in the formation of hollow structure. (c) 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1966-1974

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  • Vision maintenance and retinal apoptosis reduction in RCS rats with Okayama University-type retinal prosthesis (OUReP (TM)) implantation Reviewed

    Alamusi, Toshihiko Matsuo, Osamu Hosoya, Kimiko M. Tsutsui, Tetsuya Uchida

    JOURNAL OF ARTIFICIAL ORGANS   18 ( 3 )   264 - 271   2015.9

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    Photoelectric dye-coupled polyethylene film, designated Okayama University-type retinal prosthesis or OUReP (TM), generates light-evoked surface electric potentials and stimulates neurons. In this study, the vision was assessed by behavior tests in aged hereditary retinal dystrophic RCS rats with OUReP (TM), retinal apoptosis and electroretinographic responses were measured in dystrophic eyes with OUReP (TM). The dye-coupled films, or plain films as a control, were implanted in subretinal space of RCS rats. On behavior tests, RCS rats with dye-coupled films, implanted at the old age of 14 weeks, showed the larger number of head-turning, consistent with clockwise and anticlockwise rotation of a surrounding black-and-white-striped drum, compared with rats with plain films, under the dim (50 lux) and bright (150 lux) conditions in the observation period until the age of 22 weeks (n = 5, P < 0.05, repeated-measure ANOVA). The number of apoptotic cells in retinal sections at the site of dye-coupled film implantation was significantly smaller, compared with the other retinal sites, neighboring the film, or opposite to the film, 5 months after film implantation at the age of 6 weeks (P = 0.0021, Friedman test). The dystrophic eyes of RCS rats with dye-coupled films showed positive responses to maximal light stimulus at a significantly higher rate, compared with the eyes with no treatment (P < 0.05, Chi-square test). Electroretinograms in normal eyes of Wistar rats with dye-coupled or plain films showed significantly decreased amplitudes (n = 14, P < 0.05, repeated-measure ANOVA). In conclusions, vision was maintained in RCS rats with dye-coupled films implanted at the old age. The dystrophic eyes with dye-coupled films showed electroretinographic responses. Five-month film implantation caused no additional retinal changes.

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  • Synthesis and Light-Induced Surface Potential Observation of Retinal Prosthesis Using Polyethylene Thin Films Immobilized with Photoelectric Dyes Reviewed

    Tetsuya Uchida, Makoto Nitta, Syoko Kanashima

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   28 ( 2 )   261 - 267   2015

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    Photoelectric dyes that absorb light and convert photon energy to electric potential have previously been shown to stimulate retinal neurons in cultures. As such, we have designed a new type of retinal prosthesis using polyethylene films coupled with photoelectric dye molecules. In this study, the electric potentials on the film were observed using a scanning Kelvin probe microscope under light and dark conditions. As a result, electric potentials were observed on the film, which were dependent on light intensity and wavelength. Furthermore, the electric potentials showed a rapid on off response to light.

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  • Development of a Novel Preparation Method for Highly Porous Heat-Resistant Rigid Polymer Network Films and Evaluation of their Properties Reviewed

    Tetsuya Uchida, Ryo Ikeda, Tomoaki Suzuki, Ryotaro Nakayama

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   28 ( 2 )   163 - 167   2015

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    A rigid polymer network of poly(p-phenylene benzobisoxazole) (PBO) has excellent mechanical properties and thermal stability. Many nano voids exist within the network. However, a PBO network cannot be formed into films or fibers. Generally, PBO networks are prepared by one-step polycondensation in polyphosphoric acid. In this study, we have prepared a PBO network by a two-step method involving polymerization of a PBO network precursor (pre-PBO network) in N-methyl-2-pyrrolidone followed by thermal cyclization. Heat-resistant porous PBO network films have been successfully obtained by this two-step method. The properties of the PBO network films have been evaluated.

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  • Glass transition temperature of dried lens tissue pretreated with trehalose, maltose, or cyclic tetrasaccharide Reviewed

    Tetsuhiro Kawata, Toshihiko Matsuo, Tetsuya Uchida

    SPRINGERPLUS   3   2014.6

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    Purpose: Glass transition temperature is a main indicator for amorphous polymers and biological macromolecules as materials, and would be a key for understanding the role of trehalose in protecting proteins and cells against desiccation. In this study, we measured the glass transition temperature by differential scanning calorimetry of dried lens tissues as a model of a whole biological tissue to know the effect of pretreatment by trehalose and other sugars.Methods: Isolated porcine lenses were incubated with saline, 100 or 1000 mM concentration of trehalose, maltose, or cyclic tetrasaccharide dissolved in saline at room temperature for 150 minutes. The solutions were removed and all samples were dried at room temperature in a desiccator until no weight change. The dried tissues were ground into powder and placed in a measuring pan for differential scanning calorimetry.Results: The glass transition temperature of the dried lens tissues, as a mean and standard deviation, was 63.0 +/- 6.4 degrees C (n = 3) with saline pretreatment; 53.0 +/- 0.8 degrees C and 56.3 +/- 2.7 degrees C (n = 3), respectively, with 100 and 1000 mM trehalose pretreatment; 56.0 +/- 1.6 degrees C and 55.8 +/- 1.1 degrees C (n = 3), respectively, with 100 and 1000 mM maltose pretreatment; 60.0 +/- 8.8 degrees C and 59.2 +/- 6.3 degrees C (n = 3), respectively, with 100 and 1000 mM cyclic tetrasaccharide pretreatment. The glass transition temperature appeared lower, although not significantly, with trehalose and maltose pretreatments than with saline and cyclic tetrasaccharide pretreatments (P > 0.05, Kruskal-Wallis test). The glass transition temperature of the dried lens tissues with trehalose pretreatment appeared more noticeable on the thermogram, compared with other pretreatments.Conclusions: The glass transition temperature was measured for the first time in the dried lens tissues as an example of a whole biological tissue and might provide a basis for tissue preservation in the dried condition.

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  • Vision recovery and retinal apoptosis reduction in RCS rats with Okayama University-type retinal prosthesis

    Bai Alamusi, Toshihiko Matsuo, Osamu Hosoya, Kimiko M. Tsutsui, Tetsuya Uchida

    INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE   55 ( 13 )   2014.4

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  • Preparation and Properties of Rigid PBO Polymer Nanofibers Prepared via Crystallization From a Dilute Solution in Sulfuric Acid Reviewed

    Tetsuya Uchida, Masashi Furukawa

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   27 ( 2 )   177 - 180   2014

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    Poly(p-phenylene benzobisoxazole) (PBO) has excellent thermal stability and mechanical properties because of its rod-like rigid structure. Preparing nanofibers of PBO using ordinary methods is difficult (e.g., electrospinning) because PBO is not soluble in organic solvents. Herein, we report the preparation of PBO nanofibers with an average diameter of approximately 50 nm via crystallization from a dilute solution in sulfuric acid. In addition, a PBO nanofiber mat was prepared that exhibited extremely high thermal stability and high thermal diffusivity, etc.

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  • Behavior tests and immunohistochemical retinal response analyses in RCS rats with subretinal implantation of Okayama-University-type retinal prosthesis Reviewed

    Alamusi, Toshihiko Matsuo, Osamu Hosoya, Kimiko M. Tsutsui, Tetsuya Uchida

    JOURNAL OF ARTIFICIAL ORGANS   16 ( 3 )   343 - 351   2013.9

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    We have developed a photoelectric dye-coupled polyethylene film as a prototype of retinal prosthesis, which we named Okayama University-type retinal prosthesis. The purposes of this study are to conduct behavior tests to assess vision in Royal College of Surgeons (RCS) rats that underwent subretinal implantation of the dye-coupled film and to reveal retinal response to the dye-coupled film by immunohistochemistry. Polyethylene films were made of polyethylene powder at refined purity, and photoelectric dyes were coupled to the film surface at higher density compared with the prototype. Either dye-coupled film or dye-uncoupled plain film used as a control was implanted subretinally from a scleral incision in both eyes of an RCS rat at 6 weeks of the age. Behavior tests 2, 4, 6, and 8 weeks after implantation were conducted by observing head turning or body turning in the direction consistent with clockwise or counterclockwise rotation of a black-and-white-striped drum around a transparent cage housed with the rat. After the behavior tests at 8 weeks, rats' eyes were enucleated to confirm subretinal implantation of the films and processed for immunohistochemistry. In the behavior tests, the number of head turnings consistent with the direction of the drum rotation was significantly larger in RCS rats with dye-coupled- compared with plain-film implantation [P < 0.05, repeated-measure analysis of variance (ANOVA), n = 7]. The number of apoptotic neurons was significantly smaller in eyes with dye-coupled- compared with plain-film implantation (P < 0.05, Mann-Whitney U test, n = 6). In conclusion, subretinal implantation of photoelectric dye-coupled films restored vision in RCS rats and prevented the remaining retinal neurons from apoptosis.

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  • Synthesis and morphology control of self-condensable naphthalene-containing polyimide by using reaction-induced crystallization Reviewed

    Takashi Sawai, Kanji Wakabayashi, Shinichi Yamazaki, Tetsuya Uchida, Yoshimitsu Sakaguchi, Ryouhei Yamane, Kunio Kimura

    EUROPEAN POLYMER JOURNAL   49 ( 8 )   2334 - 2343   2013.8

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    Poly(2,6-1H-benzo[f]isoindole-1,3(2H)-dione) (PBID), which was a self-condensable naphthalene-containing polyimide, was synthesized as precipitated crystals from 6-amino-3-(ethoxycarbonyl)-2-naphthoic acid and 7-amino-3-(ethoxycarbonyl)-2-naphthoic acid by using reaction-induced crystallization during solution polymerization. The obtained PBID crystals possessed high crystallinity, excellent thermal stability and chemical resistance. They neither exhibited Tg nor Tm under the decomposition temperature. The morphology of the PBID crystals depended on not only the polymerization conditions but also the isomeric structure of the monomer, and the wide variety of the morphology appeared such as rods, plates and lathes. The plate-like crystals had fine protuberances on the surface. Copolymerization of PBID and poly(4-phthalimide) were also examined. (c) 2013 Elsevier Ltd. All rights reserved.

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  • Morphological Diversity and Nanofiber Networks of Poly(p-oxybenzoyl) Generated by Phase Separation During Copolymerization Reviewed

    Toshimitsu Ichimori, Kenta Mizuma, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    JOURNAL OF APPLIED POLYMER SCIENCE   128 ( 2 )   1282 - 1290   2013.4

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    Poly(p-oxybenzoyl) (POB) precipitates prepared by reaction-induced phase separation during copolymerization exhibit wide variety of morphologies such as fibril, needle, slab, spindle, and sphere. The morphology is significantly influenced by the copolymerization conditions of structure of trifunctional comonomers, copolymerization ratio, solvent, concentration, and temperature of the polymerization. Among them, POB nanofiber networks like a texture of nonwoven fabrics are obtained only by the polymerization of 4-acetoxybenzoic acid with 3,5-diacetoxybenzoic acid (DABA) in aromatic solvent at a concentration of 1.0-2.0% at the content of DABA in feed of 10-20 mol % at 320 degrees C. The network is comprised of fibrillar crystals connected each other at spherical nodal points. The diameters of the fibers are 90-129 nm. This network is highly crystalline and the molecules are aligned along the long direction of the fibers. Various parameters characterized the networks can be controlled by the polymerization concentration. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 128: 1282-1290, 2013

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  • Hollow Spheres of Aromatic Polyamide Prepared by Reaction-Induced Phase Separation Reviewed

    Yuji Fujitsu, Hirofumi Nakayama, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   51 ( 4 )   780 - 785   2013.2

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    Hollow spheres of aromatic polyamide are obtained by the reaction-induced phase separation during polymerization of 5-hydroxyisophthalic acid and 1,4-phenylene diamine in an aromatic solvent at a concentration of 1-2% at 320 degrees C without stirring. The hollow sphere has a dimple hole and the diameters of the hollow spheres are 3-4 mu m. The droplets are initially generated via liquid-liquid phase separation and then rigid crosslinked network structure formed the rigid skin layer on the surface of the droplets. The solidification of the droplets occurred owing to the further polymerization in them with maintaining the morphology to form the hollow spheres. The hollow spheres exhibit outstanding thermal stability. (C) 2012 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 780-785

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  • Photosensitized hydrogen evolution from water using single-walled carbon nanotube/fullerodendron/Pt(II) coaxial nanohybrids Reviewed

    Yukari Sasada, Tomoyuki Tajima, Takaaki Wada, Tetsuya Uchida, Masayasu Nishi, Takahiro Ohkubo, Yutaka Takaguchi

    NEW JOURNAL OF CHEMISTRY   37 ( 12 )   4214 - 4219   2013

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    Direct incorporation of a Pt(II) complex into the shell of SWCNT/fullerodendron coaxial nanohybrids produces a new coaxial nanowire, SWCNT/fullerodendron/Pt(II), that shows efficient photocatalytic activity for hydrogen evolution from water (Phi = 0.16 upon irradiation at 450 +/- 5 nm) without any aid of electron relay such as methyl viologen.

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  • Preparation of Novel Naphthalene Polyimide and Its Morphology Reviewed

    Takashi Sawai, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   26 ( 3 )   341 - 344   2013

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  • Morphosynthesis of poly(ether ketone) by reaction-induced crystallization during polymerization Reviewed

    Kanji Wakabayashi, Naofumi Sumi, Shinichi Yamazaki, Tetsuya Uchida, Kunio Kimura

    EUROPEAN POLYMER JOURNAL   48 ( 10 )   1787 - 1795   2012.10

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    Morphology control of poly(ether ketone) (PEK) was examined by using the crystallization during the nucleophilic aromatic substitution reaction of potassium salt of 4-fluoro-4'-hydroxybenzophenone. Polymerizations were carried out at 290 degrees C. The PEK was obtained as precipitates and its morphology was highly influenced by the polymerization condition such as the solvent, the concentration and the polymerization time. High crystalline spindle-like crystals were obtained by the polymerization in diphenyl sulfone (DPS) at a concentration of 5.0% for 2 h with the yield of 86%. The average length and width were 1.4 mu m and 300 nm respectively, and the maximum thickness was 130 nm. The surface was not smooth and it was hilly. The spindle-like crystal was likely consisted of multilayered lamellae comprised of the microcrystallites. The molecules were oriented perpendicular to the lamella. The polymerization in DPS at a higher concentration of 10.0% afforded the networks of nanofibres, of which the diameter was 100-250 nm. The obtained PEK precipitates possessed excellent thermal properties. (C) 2012 Elsevier Ltd. All rights reserved.

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  • Morphosynthesis of poly[4-(1,4-phenylene)oxyphthalimide] and copolymers prepared by reaction-induced crystallization during polymerization Reviewed

    Takashi Sawai, Kanji Wakabayashi, Shinichi Yamazaki, Tetsuya Uchida, Kunio Kimura

    JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS   50 ( 18 )   1293 - 1303   2012.9

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    Morphosynthesis of poly[4-(1,4-phenylene)oxyphthalimide] (POPI) and poly[4-(1,4-phenylene)oxyphthalimide-co-4-phthalimide] (POPI-PPI) was examined by using the crystallization during the polymerization. The POPI fibrillar crystals were obtained as precipitates with the formation of spherical aggregates of plate-like crystals. Some of the POPI fibrillar crystals were longer than 15 mu m. They possessed high crystallinity and the molecules aligned perpendicular to the long direction of the fibers. On the other hand, one-dimensional structures of POPI-PPI such as ribbon, cone, rod, and fiber were obtained as precipitates by the copolymerization. The copolymer molecules might align along the long direction of the cone-like crystals. The morphology of these poly(ether-imide)s could be controlled by not only the polymerization condition but also with the aid of copolymerization. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012

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  • Polymer/carbon nanotube composites: challenges and opportunities. Reviewed

    H.G.Chae, X.Zhang, B.L.Min, T.Lu, T.V.Sreekumar, T.Uchida, S.Kumar

    Advances in Composite Materials   2   19 - 29   2012

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  • Morphology Control of Various Aromatic Polyimidazoles-Preparation of Nanofibers Reviewed

    Jin Gong, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    JOURNAL OF APPLIED POLYMER SCIENCE   121 ( 5 )   2851 - 2860   2011.9

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    Morphology of four kinds of aromatic polyimidazoles was examined by using reaction-induced crystallization during solution polymerization at a concentration of 1% at 350 degrees C in liquid paraffin (LPF), dibenzyltoluene (DBT), and the mixture of these solvents. Aggregates of ribbon-like crystals of poly[2,6-(2,6-naphthalene)-benzobisimidazole] were obtained in LPF, and those of plate-like crystals were obtained in DBT/LPF-50 and in DBT. In contrast to this, the network structures of poly[2,2'-(2,6-naphthalene)-5,5'-bibenzimidazole)] (PNT-BBI) nanofibers with the diameter of 25 to 90 nm was mainly obtained in DBT. The network structures of the PNT-BBI nanofibers could be recognized as nonwoven fabrics of the high-performance polymers. Imidazole trimers were precipitated to form the ribbon-like crystals and then they were continuously supplied from solution to grow the crystals. Molecular weight increased by the polymerization on the surface of the crystals when they crystallized and in the crystals. The initially formed aggregates of ribbon-like crystals changed to the nanofibers with time. In the case of poly[2,6-(4,4'-biphenylene)-benzobisimidazole] and poly[2,2'-(4,4'-biphenylene)-5,5'-bibenzimidazole)], they exhibited various morphologies such as spheres, lath-like crystals, and the spherical aggregates of lath-like crystals depending on the solvent, but fibers like PNT-BBI were not formed. The crystals obtained in this study possessed very high crystallinity and the outstanding thermal stability measured by TGA. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 2851-2860, 2011

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  • Electron Microscope Observation and Structure Control of Single-Wall Carbon Nanotube Bundles, Single Crystals and Composite Fibers

    Tetsuya Uchida, Naoya Tsugawa, Takuya Akaishi

    SEN-I GAKKAISHI   67 ( 5 )   P132 - P135   2011.5

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  • Micro-flowers of poly(p-phenylene pyromelliteimide) crystals Reviewed

    Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    POLYMER   52 ( 3 )   837 - 843   2011.2

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    Morphology control of poly(p-phenylene pyromelliteimide) (PPPI) crystals was examined using reaction-induced crystallization of oligomers during solution polymerization of self-polymerizable N-(4'-aminophenyl)-3-carboxyl-4-alkoxycarbonylPhthalimide. Micro-flowers of the PPP1 needle-like crystals were formed in which the needle-like crystals grew radially from the center part as petals. The molecules aligned regularly along the long axis of the needle-like crystal. The structure of alkoxy group in the monomer and the monomer concentration influenced the size of the needle-like crystals, and their average length and width were changeable from 640 nm to 1.69 mu m and from 110 nm to 210 nm, respectively. The average thickness was 20 nm. The obtained micro-flowers possessed high crystallinity and exhibited excellent thermal stability. (C) 2010 Elsevier Ltd. All rights reserved.

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  • Preparation of Poly(p-phenylenepyromelliteimide) Microspheres with Rugged Surfaces Using Crystallization During Isothermal Polymerization Reviewed

    Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    MACROMOLECULAR CHEMISTRY AND PHYSICS   212 ( 2 )   159 - 167   2011.1

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    Preparation of discrete PPPI microspheres was examined using the crystallization of oligomers during isothermal polymerization of PMDA and p-phenylene diisocyanate, and that of pyromellitic dithioanhydride and PPDA in poor solvents. In contrast to PPPI microspheres with smooth surfaces that were previously prepared by phase-separation during the polymerization of PPDA and PMDA, the microspheres obtained here consisted of flake-like lamellae with rugged surfaces. The diameters of the microspheres ranged from 0.5 to 6.7 mu m. They exhibited excellent thermal stability depending on the monomers. These results provide a new preparative procedure of the PPPI microsphere with a rugged surface.

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  • One-Pot Preparation of Aromatic Poly(azomethine ester) Fibrillar Crystals Using Reaction-Induced Crystallization Reviewed

    Jin Gong, Yasuhide Yakushi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   49 ( 1 )   127 - 137   2011.1

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    Polymerizations of 4-(4-acetoxybenzylideneamino)-benzoic acid were performed in dibenzyltoluene (DBT) and a mixture of DBT and liquid paraffin at 350 degrees C for 6 h. Fibrillar crystals of poly[4-(4-oxybenzylideneamino)benzoyl] (POAB) having the width of 50-450 nm and the length of over 15 pm were obtained by the crystallization during the polymerization. The fibrillar crystals possessed high crystallinity and the molecular chains aligned perpendicular to the long axis of the fibrillar crystals. Plate-like crystals were initially formed by the crystallization of oligomers, and then they changed to the fibrillar crystals via the formation of bundle-like crystals after 1 h. Molecular weight increased by the further polymerization in the crystals. Based on these results, one-pot preparation of the fibrillar POAB crystals was examined by the polymerization of 4-acetoxybenzaldehyde and 4-aminobenzoic acid. The polymerization at 180 degrees C for 2 h and then at 350 degrees C for 6 h afforded the fibrillar crystals with a small amount of the ribbon-like crystals. Although the side-reaction to generate the p-benzamide sequences was not completely depressed, the sequence of heating in which 180 degrees C for the formation of the azomethine linkage and then 350 degrees C for the formation of the ester linkage was preferable to prepare the fibrillar POAB crystals. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 127-137, 2011

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  • Denaturation temperature of dried lens tissue rises with trehalose pretreatment Reviewed

    Jianan Sun, Toshihiko Matsuo, Tetsuya Uchida

    JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY   103 ( 1 )   387 - 391   2011.1

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    Trehalose, a non-reducing disaccharide, is known as an exceptional protector against desiccation and heat stress. Differential scanning calorimetry is a simple tool to determine thermodynamic parameters concerning the structural state of proteins. In this study, we measured denaturation temperature (or melting temperature) of dried lenses to know the effect of trehalose pretreatment. Isolated porcine lenses were incubated in wells without any solution or with saline, 100 mM trehalose, or 100 mM cyclic tetrasaccharide in saline at room temperature for 150 min. The solutions were removed, and all lens samples were dried at room temperature and in room humidity until the weight showed no change. The nucleus of each sample was taken out and placed on a measuring platform for differential scanning calorimetry. The denaturation temperature of the dried lenses significantly rose by about 10 degrees C with 100 mM trehalose pretreatment, compared to no pretreatment, pretreatment with saline or 100 mM cyclic tetrasaccharide (P < 0.05, analysis of variance, P < 0.05, Student-Newman-Keuls tests, n = 7). The denaturation temperature showed no difference among the dried lenses with no pretreatment or pretreatment by saline or cyclic tetrasaccharide. In conclusion, pretreatment with trehalose raises denaturation temperature of the dried porcine lens. Trehalose might stabilize the dried tissue structure to get a higher denaturation temperature.

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  • Poly[2,6-(1,4-phenylene)-benzobisimidazole] Nanofiber Networks Reviewed

    Jin Gong, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    MACROMOLECULAR CHEMISTRY AND PHYSICS   211 ( 20 )   2226 - 2232   2010.10

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    The preparation of poly[2,6-(1,4-phenylene)-benzobisimidazole] (PPBI) nanofibers was examined using the crystallization of oligomers during isothermal polymerization of self-polymerizable 2-(1,4-carbophenoxyphenyl)-5,6-diaminobenzimidazole. The polymerization was carried out at 350 degrees C at a concentration of 1w-t.-% for 6 h in three kinds of solvent. The solvent influenced the morphology of PPBI precipitates significantly, and PPBI nanofiber networks were successfully formed in DBT, of which the width ranged from 30 to 110 nm. Molecules were aligned along the long axis of nanofibers. A fibrillar morphology with molecular orientation is ideal for high performance materials such as reinforcements, non-woven fabrics and so on. The nanofiber networks exhibit the highest thermal stability.

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  • Poly(2,5-benzimidazole) nanofibers prepared by reaction-induced crystallization Reviewed

    Kazuya Kimura, Jin Gong, Shin-ichiro Kohama, Shinichi Yamazaki, Tetsuya Uchida, Kunio Kimura

    POLYMER JOURNAL   42 ( 5 )   375 - 382   2010.5

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    Morphological control of poly(2,5-benzimidazole) (PBI) was examined by reaction-induced phase separation of oligomers during polymerization to prepare nanofibers. Three monomers, 3,4-diaminobenzoic acid (DABA), 3,4-diacetoamidebenzoic acid (DAcBA) and phenyl 3,4-diaminobenzoate (PDAB), were used to synthesize PBI. Polymerizations were carried out at 350 degrees C in a mixture of dibenzyltoluene isomers. Polymerization of DABA yielded spheres with plate-like crystals on their surface. Polymerization of DAcBA yielded almost no precipitates because of the high solubility of DAcBA oligomers. By contrast, polymerization of PDAB yielded aggregates of PBI nanofibers (of which the average diameter was similar to 60 nm), which resembled nonwoven fabrics. These fibers were formed by precipitation of (2,5-benzimidazole) oligomers and their subsequent polymerization into a developing crystal structure. The structure of the monomer significantly influenced the morphology of the PBI product, and PDAB was preferable for the preparation of PBI nanofibers. The temperature of 10% N-2 weight loss in these nanofibers was in the range of 634-644 degrees C and they were thermally stable. Polymer Journal (2010) 42, 375-382; doi:10.1038/pj.2010.20; published online 17 March 2010

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  • Safety, efficacy, and quality control of a photoelectric dye-based retinal prosthesis (Okayama University-type retinal prosthesis) as a medical device Reviewed

    Toshihiko Matsuo, Tetsuya Uchida, Kenichi Takarabe

    JOURNAL OF ARTIFICIAL ORGANS   12 ( 4 )   213 - 225   2009.12

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    Patients with retinitis pigmentosa lose photoreceptor cells as a result of genetic abnormalities and hence become blind. Neurons such as bipolar cells and ganglion cells remain alive even in the retina of these patients, and ganglion cells send axons to the brain as the optic nerve. The basic concept of retinal prostheses is to replace dead photoreceptor cells with artificial devices to stimulate the remaining neurons with electric currents or potentials. Photodiode arrays and digital camera-type electrode arrays are the two main approaches for retinal prostheses to stimulate retinal neurons, but these arrays have the problems of poor biocompatibility, low sensitivity, and low output of electric currents, and hence have a requirement for external electric sources (batteries). To overcome these problems, we are developing photoelectric dye-based retinal prostheses that absorb light and convert photon energy to generate electric potentials. The prototype, using a photoelectric dye-coupled polyethylene film, could induce intracellular calcium elevation in photoreceptor-lacking embryonic retinal tissues and cultured retinal neurons. The subretinal implantation of the prototype in the eyes of Royal College of Surgeons (RCS) rats led to vision recovery as proved by a behavior test. The photoelectric dye that was chosen for the prototype did not exhibit any cytotoxicity. The surface potentials of the photoelectric dye-coupled film showed a rapid on-and-off response to illumination with a threshold for light intensity as measured by a Kelvin probe system. Photoelectric dye-based retinal prostheses are thin and soft, and therefore, a sheet of the film of large size, corresponding to a large visual field, could be inserted into the vitreous and then to the subretinal space through a small opening by rolling up the film. Clinical studies of photoelectric dye-based retinal prostheses in patients with retinitis pigmentosa who lose sight will be planned after the manufacturing control and the quality control had been established for the medical device.

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  • Direct Synthesis of Wholly Aromatic Polyamides by Using Reaction-Induced Crystallization Reviewed

    Kazufumi Kobashi, Kentaro Kobayashi, Haruki Yasuda, Kentaro Arimachi, Testuya Uchida, Kanji Wakabayashi, Shinichi Yamazaki, Kunio Kimura

    MACROMOLECULES   42 ( 16 )   6128 - 6135   2009.8

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    Direct synthesis of rigid-rod aromatic polyamides was studied without condensation reagents by using reaction-induced crystallization of oligomers during solution polymerization. Polymerizations of p-aminobenzoic acid were carried out in an aromatic solvent at a polymerization concentration of 20% at 350 degrees C. High molecular weight poly(p-benzamide) (PBA) was obtained in the form of plate-like crystals, and the highest molecular weight was 11.6 x 10(3). In this polymerization, the oligomers were formed in the solution by the condensation reaction with the elimination of water. When the molecular weight of oligomers exceeded the critical value, the oligomers were precipitated by crystallization via supersaturated state to form the plate-like crystals. The molecular weight increased by the polymerization between the oligomers on and in the crystals. Poly(p-phenylene isophthalamide) (PPIA) was also obtained in the form of plate-like crystals by the polymerization of p-phenylene diamine (PPDA) and isophthalic acid (IPA) under the same condition as that of PBA. These results exhibited the thermally direct synthesis of infusible aromatic polyamides. Sequential addition of monomers into this heterogeneous polymerization was examined to increase the molecular weight. In the step-growth polymerization, the addition of monomers into the homogeneous polymerization could not increase the molecular weight because it was determined by the extent of reaction and reshuffled by the transamidation reaction. However, the addition of PPDA and IPA during the polymerization resulted in the increase in the molecular weight of PPIA. This result gave possibly a novel procedure for the preparation of high molecular weight condensation-type polymers.

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  • Preparation of Poly(4 '-oxy-4-biphenylcarbonyl) Needlelike Crystals with the Aid of Copolymerization Reviewed

    Naomi Yoshida, Yasuhiro Kurihara, Shin-ichiro Kohama, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    MACROMOLECULES   41 ( 20 )   7571 - 7578   2008.10

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    Preparation of poly(4'-oxy-4-biphenylcarbonyl) (POBP) needlelike crystals was examined by using reaction-induced crystallization of oligomers during copolymerization of 4-(4-aceloxypheilyl)benzoic acid (APBA) and 4-acetoxybenzoic acid (ABA). Polymerizations were carried out in aromatic solvent at various ABA molar ratios in feed (chi(f)). When they chi(f) was 20-10 mol %, starlike aggregates of needlelike crystals and fibrillated slablike crystals were separately formed, exhibiting similar morphology to poly(4-oxybenzoyl) and POPB crystals. 4-(Oxyphenyl)benzoyl (OPB) homo-oligomers and co-oligomers rich in OPB moiety were more rapidly precipitated due to the lower solubility, and the slablike crystals were formed. Afterward, 4-oxybenzoyl (013) homo-oligomers and the co-oligomers rich in OB moiety were precipitated to form spindlelike crystals. The OPB homo-oligomers and the co-oligomers rich in OPB moiety were continuously crystallized on both crystals due to the high degree of supersaturation. and the spindlelike crystals grew to the needlelike crystals mainly comprised of POBP. Copolymerization of 4-(4-acetoxybenzoyloxy)benzoic acid and APBA at chi(f) of 10 mol % yielded the needlelike crystals without coexisting fibrillated slablike crystals. This result provides a new methodology for morphology control with the aid of copolymerization.

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  • Preparation of poly(4-phthalimide) nanoribbon by reaction-induced crystallization Reviewed

    Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    MACROMOLECULES   41 ( 13 )   4607 - 4614   2008.7

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    The morphology of poly(4-phthalimide) (PPI) crystals was examined by using reaction-induced crystallization of oligomers during solution polymerization. Polymerizations of alkyl 4-aminophthalates such as I-ethyl 4-aminophthalate (1EAP), 2-ethyl 4-aminophthalate, 1-hexyl 4-aminophthalate, and 2-hexyl 4-aminophthalate were carried out at 330 degrees C in a mixture of isomers of dibenzyltoluene without stirring. Nanoscale PPI ribbons having smooth surface were formed by the polymerizations of these monomers. The ribbons prepared from 1EAP at a concentration of 2.0% for 24 h were averagely 12 mu m in length, 150 urn in width, and 8 nm in thickness, in which the molecular chains aligned along the long axis of the ribbon. The phase-separated oligomers were fully cyclized imide oligomers, and this is of great importance for the formation of the ribbon. The obtained ribbons possessed high crystallinity and exhibited excellent thermal stability.

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  • Morphology control of poly(2,2'-phenylene-5,5'-bibenzimidazole) by reaction-induced crystallization during polymerization Reviewed

    Shin-ichiro Kohama, Jin Gong, Kazuya Kimura, Shinichi Yamazaki, Tetsuya Uchida, Kaoru Shimamura, Kunio Kimura

    POLYMER   49 ( 7 )   1783 - 1791   2008.4

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    Morphology control of polybenzimidazoles was examined by reaction-induced phase separation during polymerization. Polymerizations of 3,3'-diaminobenzidine with terephthalic acid or diphenyl terephthalate were carried out in poor solvents. The morphology of the precipitated poly[2,2'-(1,4-phenylene)-5,5'-bibenzimidazole] (PpBBI) was significantly influenced by the polymerization conditions, and the aggregates of nano-scale PpBBl fibers were obtained by the polymerization at a concentration of 3-5% and 320-350 degrees C in dibenzyltoluene. The average diameter of the fibers was ca. 50 mn and inherent viscosities of the precipitates were 0.35-0.58 dL g(-1). They possessed high crystallinity and thermal stability. The oligomers were precipitated first by the reaction-induced crystallization to form the highly crystalline lath-like crystals at an initial stage of polymerization. Then the lath-like crystals were split into disentangled aggregates of fine fibers with maintaining the high crystallinity. The polymerization mainly proceeded when the oligomers were registered into the crystals. The obtained aggregates of nano-scale fibers could be recognized as nonwoven fabrics. Morphology control of poly [2,2'-(1,3-phenylene)-5,5'-bibenzimidazole] was also examined and particles were mainly formed. (c) 2008 Elsevier Ltd. All rights reserved.

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  • Glial reaction to photoelectric dye-based retinal prostheses implanted in the subretinal space of rats Reviewed

    Takayuki Tamaki, Toshihiko Matsuo, Osamu Hosoya, Kimiko M. Tsutsui, Tetsuya Uchida, Kazuo Okamoto, Akihito Uji, Hiroshi Ohtsuki

    JOURNAL OF ARTIFICIAL ORGANS   11 ( 1 )   38 - 44   2008.4

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    We have designed a new type of retinal prosthesis using polyethylene films coupled with photoelectric dye molecules that absorb light and convert photon energy to electric potentials. An extruded-blown film of high-density polyethylene was used as the original polyethylene film. Recrystallized film was made by recrystallization from the melting of the original polyethylene film. A photoelectric dye,2-[2-[4-(dibutylamino)phenyl]ethenyl]-3-carboxymethylbenzothiazolium bromide, was coupled to the two types of polyethylene films through amide linkages. Samples of the original dye-coupled film, the dye-coupled recrystallized film, and the dye-uncoupled plain film were implanted in the subretinal space of normal adult rats. Frozen sections were cut from the eyes enucleated at 1 week or 1 month and were either stained with hematoxylin and eosin, stained immunohistochemically for glial fibrillary acidic protein (GFAP), or processed for in situ apoptosis detection. The results revealed that retinal tissue damage was negligible with no inflammatory cells and few apoptotic cells. GFAP was significantly up-regulated in retinal sites with the implantation of all types of polyethylene films at 1 week, compared with the adjacent retinal sites (P < 0.005, analysis of variance). The GFAP up-regulation was also present at 1 month for the plain film and dye-coupled recrystallized film (P < 0.05). Glial cell encirclement around the films increased significantly between 1 week and 1 month (P = 0.023, two-factor analysis of variance) but was not significantly different among the three types of polyethylene films (P = 0.4531). These results showed evidence of glial reactions to the photoelectric dye-coupled polyethylene films implanted into the subretinal space of rat eyes and also proved their basic biological safety.

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  • Fabrication of particles and crystals of poly(p-phenylene pyromelliteimide) and the study on crystal structure Reviewed

    Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura, Kaoru Shimamura

    MACROMOLECULES   40 ( 2 )   239 - 246   2007.1

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    Morphologies of poly(p-phenylene pyromelliteimide) (PPPI) were investigated by using phase separation during polymerization of pyromellitic dianhydride (PMDA) and p-phenylene diamine (PPDA). Polymerizations were carried out at 330 degrees C for 6 h. PPDA was added to the solution of PMDA in an aromatic solvent at various temperatures after PMDA was entirely dissolved. The morphology of the precipitates was drastically changed with the temperature of PPDA addition (Tad). When Tad was 240 degrees C, the fine particles were formed through the formation of droplets via liquid-liquid phase separation. On the contrary, when Tad was higher than 280 degrees C, the mixture of lozenge-shaped crystals and starlike aggregates of needlelike crystals were formed by the crystallization of oligomers. Tad influenced the degree of imidization of oligomers, resulting in the variation in the morphology of PPPI. Crystal structure and molecular chain orientation of the lozenge-shaped crystals were also investigated by high-resolution transmission electron microscope.

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  • Light-induced electron transfer on the single wall carbon nanotube surrounded in anthracene dendron in aqueous solution Reviewed

    Atula S. D. Sandanayaka, Yutaka Takaguchi, Tetsuya Uchida, Yuuki Sako, Yu Morimoto, Yasuyuki Araki, Osamu Ito

    CHEMISTRY LETTERS   35 ( 10 )   1188 - 1189   2006.10

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    Light illumination of single-wall carbon nanotubes (SWCNTs) dispersed with anthracene (An) dendrons afforded the accumulation of the reduced form of methyl viologen in the presence of a hole shifter. With the helps of the fluorescence lifetime and transient absorption measurements, the charge-separation process from the excited state of the hybrides of An dendrimer to SWCNT was confirmed.

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  • Intracellular calcium response and adhesiveness of chick embryonic retinal neurons to photoelectric dye-coupled polyethylene films as prototypes of retinal prostheses Reviewed

    Akihito Uji, Toshihiko Matsuo, Tetsuya Uchida, Kaoru Shimamura, Hiroshi Ohtsuki

    ARTIFICIAL ORGANS   30 ( 9 )   695 - 703   2006.9

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    Photoelectric dyes, which absorb light and convert photon energy to electric potentials, were shown to stimulate retinal neurons in culture. One of these dyes coupled with polyethylene film surface, as a prototype of retinal prostheses, could induce intracellular calcium elevation in chick embryonic retinal tissues. In this study, we used retinal cells from chick embryos in which no photoreceptor outer segments yet developed, and assessed cell adhesiveness and response to the original and modified types of our retinal prostheses. Extruded-blown film of high density polyethylene was used as the original polyethylene film. Polyethylene film surface was modified either by coupling with type 1 collagen or by crystallization from the melt of the original polyethylene film. A photoelectric dye, 2-[2-[4-(dibutylamino)phenyl]ethenyl]-3-carboxymethylbenzothiazolium bromide, was coupled to these different types of polyethylene films through amide linkage. Retinal cells from chick embryos at the 12-day embryonic stage were cultured on the surface of dye-coupled films. The response of retinal cells to the dye-coupled films was observed by calcium imaging. Cell types, either neurons or glial cells, were detected by immunocytochemical staining and also observed by scanning electron microscopy (SEM). Intracellular calcium elevation was observed in cells, including both neurons and glial cells, on the surface of the original dye-coupled film, collagen-coated dye-coupled film, and dye-coupled recrystallized film, in contrast with no response of cells cultured on the dye-uncoupled plain film. Retinal neurons grew upon colonies of glial cells settling on the surface of all different types of the films. The number of retinal neurons on the collagen-coated dye-coupled film and dye-coupled recrystallized film was significantly larger than the number of neurons on the dye-uncoupled plain film (P = 0.0004, analysis of variance; P < 0.05, Tukey-Kramer test). With SEM, Muller cell-like large cells covered the original dye-coupled film and collagen-coated dye-coupled film, while neuron-like small cells settled directly on the dye-coupled recrystallized film and also formed large colonies on Muller-like cells. Retinal neurons and glial cells were cultured directly on the different types of dye-coupled polyethylene films. Photoelectric dye-coupled polyethylene films could be used as prototypes of retinal prostheses.

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  • Morphology and modulus of vapor grown carbon nano fibers Reviewed

    Tetsuya Uchida, David P. Anderson, Marilyn L. Minus, Satish Kumar

    JOURNAL OF MATERIALS SCIENCE   41 ( 18 )   5851 - 5856   2006.8

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    Two types of morphologies have been observed in vapor grown carbon nano fibers (CNFs) using transmission electron microscopy (TEM). In one case, a truncated cone microstructure was observed, with outer and inner diameters of 60 and 25 nm, respectively. In this type of CNF, graphite sheets were oriented at about 15 degrees to the fiber axis. The second type of fiber was a double-layer CNF with outer and inner diameters of 83 and 20 nm, respectively. A truncated cone structure was also observed in the double-layer CNF. Graphite sheets in the outer layer of the double-layer fibers were oriented along the nano fiber axis. Tensile modulus for the first type of nano fiber along its axis was calculated to be 50 GPa, and for the second type of fiber the calculated modulus value was in the 100-775 GPa range, depending on the outer layer orientation. Modulus calculations based on these two morphologies explain the wide ranging experimental CNF modulus values reported in the literature.

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  • Electrooxidation of alcohols in an N-oxyl-immobilized rigid network polymer particles/water disperse system Reviewed

    J Kubota, T Ido, M Kuroboshi, H Tanaka, T Uchida, K Shimamura

    TETRAHEDRON   62 ( 20 )   4769 - 4773   2006.5

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    The electrooxidation of alcohols in an aqueous disperse system with N-oxyl-immobilized poly(p-phenylene benzobisthiazole) network polymer particles (PBZT(NT)-N-Oxyl) as a disperse phase was performed successfully in a simple beaker-type undivided cell tinder a constant current condition to afford the corresponding ketones, aldehydes, and/or carboxylic acid in moderate to good yields. Recycle use of both the PBZT(NT)-N-Oxyl particles and the aqueous media could be achieved successfully by immobilization of additional N-oxyl moiety on the polymer particles in an appropriate interval. Notably, the shape and the particle size of PBZT(NT)-N-Oxyl were not appreciably changed even after 60 times recycle use. (c) 2006 Elsevier Ltd. All rights reserved.

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  • Atomic force microscopic observation of trehalose-treated and dried corneal epithelial surface Reviewed

    Yuko Izawa, Toshihiko Matsuo, Tetsuya Uchida, Kaoru Shimamura, Hiroshi Ohtsuki

    Cell Preservation Technology   4 ( 2 )   117 - 122   2006

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    To search for the mechanism of the effect of trehalose on the ocular surface applied as eye drops, we observed trehalose-treated and dried corneal epithelial surfaces of porcine eyes with atomic force microscopy. Full-thickness corneal pieces, 5 × 5 mm in size, were cut out from enucleated porcine eyes. Three kinds of disaccharides, trehalose, maltose, and sucrose, dissolved in saline at 100 mM concentration, and saline as a control, were applied to the epithelial surface of the full-thickness corneal pieces for 1 min. Excess fluid was then absorbed by cotton tips at the epithelial edge of the pieces, and the corneal pieces were dried naturally at room temperature and in room humidity for 72 h. The dried corneal epithelial surfaces were observed first with a dissecting microscope and then fixed on the observation platform for atomic force microscopy. With dissecting microscopy, trehalose-treated corneal epithelial surfaces appeared smoother than saline-, maltose-, or sucrose-treated surfaces. With atomic force microscopy in a tapping mode, saline-, maltose-, and sucrose-treated corneal epithelial surfaces had a larger number of pits in greater sizes than trehalose-treated surfaces. The number of pits measuring 0.14 μm or larger was significantly less in trehalose-treated corneal epithelial surfaces than in saline-treated surfaces (p = 0.0326, analysis of variance [ANOVA], p &lt
    0.05, Tukey-Kramer test). No significant difference was found in the number of pits between maltose- or sucrose-treated surfaces and saline-treated surfaces. Mean roughness, an indicator for surface roughness, was significantly lower in trehalose-treated surfaces than in sucrose-treated surfaces (p = 0.0181, ANOVA, p &lt
    0.05, Tukey-Kramer test). Trehalose-treated corneal epithelial surfaces are smoother than saline-, maltose-, or sucrose-treated surfaces. One effect of trehalose on the ocular surface is to keep the corneal epithelial surface smooth in drying condition. © Mary Ann Liebert, Inc.

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  • Fullerodendron-assisted dispersion of single-walled carbon nanotubes via noncovalent functionalization Reviewed

    Y Takaguchi, M Tamura, Y Sako, Y Yanagimoto, S Tsuboi, T Uchida, K Shimamura, S Kimura, T Wakahara, Y Maeda, T Akasaka

    CHEMISTRY LETTERS   34 ( 12 )   1608 - 1609   2005.12

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    Single-walled carbon nanotubes (SWNTs) were well dispersed in both water and organic solvent by the use of fullero-dendron as a dispersant. A C-60 moiety at the focal point of dendron plays a crucial role in the dispersing process, because dendron having an anthracene unit at the focal point can not disperse SWNTs in THE The dispersions of SWNTs were characterized by UV-vis-NIR spectroscopy, Raman spectroscopy, SEM, HRTEM, and AFM.

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  • Single wall carbon nanotube dispersion and exfoliation in polymers Reviewed

    T Uchida, S Kumar

    JOURNAL OF APPLIED POLYMER SCIENCE   98 ( 3 )   985 - 989   2005.11

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    Dispersion and exfoliation of single wall carbon nanotubes (SWNTs) have been studied in poly(acrylonitrile) (PAN), poly(p-phenylene benzobisoxazole) (PBO) solutions, and composite fibers using transmission electron microscopy. As a result of polymer assisted dispersion and exfoliation, the average SWNT bundle diameter in SWNT/ PAN (5/95) was 11 nm, while the average diameter for the pristine SWNT bundles was about 30 nm. High resolution TEM of SWNT/PBO (10/90) composite fibers did not reveal the presence of SWNT aggregates or bundles, suggesting SWNT exfoliation as individuals. On the other hand, both oriented and unoriented nanotube bundles have been observed in SWNT/PBO samples containing 15 wt % nanotubes. Carbon nanotubes are 10(5) times more radiation resistant than flexible polymers such as polyethylene, and 10(5) times more resistant than highly radiation resistant polymers such as PBO. Therefore in the high resolution TEM study of nanotube/polymer composites, nanotubes can be observed long after the polymer has been damaged by electron radiation. (c) 2005 Wiley Periodicals, Inc.

    DOI: 10.1002/app.22203

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  • A comparison of reinforcement efficiency of various types of carbon nanotubes in poly acrylonitrile fiber Reviewed

    HG Chae, TV Sreekumar, T Uchida, S Kumar

    POLYMER   46 ( 24 )   10925 - 10935   2005.11

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    Polyacrylonitrile (PAN)/carbon nanotubes (CNTs) composite fibers were spun from solutions in dimethyl acetamide (DMAc), using single wall (SWNTs), double wall (DWNTs), multi wall (MWNTs) carbon nanotubes, and vapor grown carbon nanofibers (VGCNFs). In each case, CNT content was 5 wt% with respect to the polymer. Structure, morphology, and properties of the composite fibers have been characterized using X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopy, tensile tests, dynamic mechanical tests, as well as thermal shrinkage. While all nanotubes contributed to property improvements, maximum increase in modulus (75%) and reduction in thermal shrinkage (up to 50%) was observed in the SWNT containing composites, and the maximum improvement in tensile strength (70%), strain to failure (110%), and work of rupture (230%) was observed in the MWNTs containing composites. PAN orientation is higher in the composite fiber (orientation factor up to 0.62) than in the control PAN fiber (orientation factor 0.52), and the PAN crystallite size in the composite fiber is up to 35% larger than in the control PAN (3.7 nm), while the overall PAN crystallinity diminished slightly. Nanotube orientation in the composite fibers is significantly higher (0.98 for SWNTs, 0.88 for DWNTs, and 0.91 for MWNTs and VGCNFs) than the PAN orientation (0.52-0.62). Improvement in low strain properties (modulus and shrinkage) was attributed to PAN interaction with the nanotube, while the improvement in high strain properties (tensile strength, elongation to break, and work of rupture) at least in part is attributed to the nanotube length. Property improvements have been analyzed in terms of nanotube surface area and orientation. (c) 2005 Elsevier Ltd. All rights reserved.

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  • Development of a new hybrid gel phantom using carrageenan and gellan gum for visualizing three-dimensional temperature distribution during hyperthermia and radiofrequency ablation Reviewed

    M Kuroda, H Kato, K Hanamoto, K Shimamura, T Uchida, Y Wang, S Akaki, JI Asaumi, K Himei, M Takemoto, S Kanazawa, K Shibuya, S Kawasaki, Y Hiraki

    INTERNATIONAL JOURNAL OF ONCOLOGY   27 ( 1 )   175 - 184   2005.7

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    We developed a new hybrid gel phantom using carrageenan and gellan gum for the purpose of visualizing three-dimensional temperature distribution. The phantom, which contains carrageenan, gellan gum, non-ionic surface active agent, potassium chloride, n-butanol, sodium azide, and water, shows good transparency at room temperature, and has the advantage that the heated region becomes white and opaque due to segregation of the surface active agent. Carrageenan and gellan gum were added to improve the transparency and fragility of the hybrid gel. Potassium chloride was used to adjust the electrical conductivity of the gel to a range of 5-130 MHz, so that it would be equivalent to that of muscle tissue for each frequency used by electromagnetic heating devices. N-butanol was used to adjust the clouding temperature to a range between 45 and 55 degrees C. In the present study we clarified the important properties of the new phantom, and developed formulae for easy determination of the amounts of ingredients necessary for the desired clouding temperature and electric conductivity. The characteristics of this phantom are: a) a solid form to avoid convection by heat conduction; b) sufficient strength without fragility to form a torso without the use of a reinforcing agent; c) high transparency at room temperature and visualization of the heating area as a white turbidity; d) time-lapse and accurate visualization of the changing temperature area without thermal hysteresis; e) electrical properties similar to those of human tissues; f) ease of production; and g) low cost and good safety. This phantom might assist oncologists in their routine checking and study of the performance of electromagnetic heating devices for hyperthermia and radiofrequency ablation.

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  • Carbon nanotube core-polymer shell nanofibers Reviewed

    J Liu, T Wang, T Uchida, S Kumar

    JOURNAL OF APPLIED POLYMER SCIENCE   96 ( 5 )   1992 - 1995   2005.6

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JOHN WILEY & SONS INC  

    Single-walled carbon nanotube (SWNT)/ poly(methyl methacrylate) and SWNT/polyacrylonitrile composite nanofibers were electrospun with SWNT bundles as the cores and the polymers as the shells. This was a novel approach for processing core (carbon nanotube)-shell (polymer) nanofibers. Raman spectroscopy results show strain-induced intensity variations in the SWNT radial breathing mode and an upshift in the tangential (G) and overtone of the disorder (G') bands, suggesting compressive forces on the SWNTs in the electrospun composite fibers. Such fibers may find applications as conducting nanowires and as atomic force microscopy tips. (c) 2005 Wiley Periodicals, Inc.

    DOI: 10.1002/app.21662

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  • Novel network morphology of poly(p-oxybenzoyl) Reviewed

    K Kimura, S Kohama, S Kondoh, T Uchida, Y Yamashita, T Oohazama, Y Sakaguchi

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   43 ( 8 )   1624 - 1634   2005.4

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    Polymerization of 4-acetoxybenzoic acid (ABA) with 3,5-diacetoxybenzoic acid (DABA) was examined to control the morphology of poly(p-oxybenzoyl) (POB). Polymerizations were carried out at a concentration of 1.0% in an aromatic solvent Therm S-1000 (R) (mixture of dibenzyltoluene) at 320 degrees C. Polymerization of ABA yielded the POB fibrillar crystals, but the polymerization with DABA at a concentration in the feed (chi(f)) of 0.10-0.15 afforded novel network structures comprised of spheres connected by fibrillar crystals. The diameter of the spheres prepared at chi(f) of 0. 15, which were 0. 7 and 5.0 mu m, showed bimodality. The network distance, fibril length, and fibril width were 6.1, 2.6, and 0.1 mu m, respectively. They possessed high crystallinity. The network structure was formed as follows. Co-oligomers were first precipitated in the beginning of the polymerization by liquid-liquid phase separation to form the microdroplets. The fibrillar crystals were formed in the coalesced spheres by the crystallization of oligomers induced by the increase of molecular weight. The fibrillar crystals connecting the spheres gradually appeared owing to the shrinkage of the spheres. The fibrillar crystals grew from the surface of the spheres with the crystallization of homo-oligomers of 4-oxybenzoyl units, and finally the network structure was completed. (c) 2005 Wiley Periodicals, Inc.

    DOI: 10.1002/pola.20639

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  • Polymer whiskers based on p-mercaptobenzoyl and p-oxybenzoyl blocks Reviewed

    K Kobashi, K Kimura, T Uchida, Y Yamashita, K Shimamura

    POLYMER   46 ( 7 )   2191 - 2200   2005.3

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    Preparation of polymer whisker based on p-mercaptobenzoyl (S) and p-oxybenzoyl (0) blocks was examined by the polymerization of Sacetyl-4-mercaptobenzoic acid (AMBA) and the following addition of 4-acetoxybenzoic acid (ABA). Polymerization of AMBA was carried out in liquid paraffin at 300 degrees C for 3 h yielding poly(p-mercaptobenzoyl) (PMB) whisker, and then ABA was added stepwise at 3-hour intervals into the solution. Initial polymerization concentration was 1.98%. The length of the whisker increased with the addition and it became 26.7 mu m from 20.1 mu m after third ABA addition. The width increased very slightly. Both length and width increased with polymer yield but the length increased preferentially rather than the width. The number of whiskers was constant even after the addition of ABA and poly (p-oxybenzoyl) (POB) whisker was not newly formed by the addition. Microscopic FT-IR and selected area electron diffraction measurements revealed that polymer molecules were aligned along the long axis of the whiskers, and the center and tip parts were comprised of PMB crystal and POB crystal, respectively. The polymer whisker based on S and 0 blocks was successfully prepared as grafting POB crystal on PMB whisker with stepwise addition of ABA. Thermal property of the resulting whiskers was also discussed. (c) 2005 Elsevier Ltd. All rights reserved.

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  • Direct synthesis of poly(4 '-oxy-4-biphenylcarbonyl) and poly(2-oxy-6-naphthoyl) under nonstoichiometric conditions Reviewed

    S Kohama, K Kimura, T Uchida, S Umehara, Y Ikemoto, Y Yamashita

    POLYMER INTERNATIONAL   54 ( 2 )   471 - 480   2005.2

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    Direct synthesis of poly(4'-oxy-4-biphenylcarbonyl) (POBP) and poly(2-oxy-6-naphthoyl) (PON) was examined by polycondensation of 4'-hydroxy-4-biphenylcarboxylic acid (HBPA) and 2-hydroxy-6-naphthoic acid (HNA) in the presence of 4-ethoxybenzoic anhydride or 2-naphthoic anhydride as condensation reagents. Polymerizations were carried out at 320degreesC in aromatic solvents and liquid paraffin. POBP, having a number-average degree of polymerization (DPn) of 38, was obtained as plate-like crystals at the molar ratio of HBPA and anhydride of 50 mol%. PON was also obtained as plate-like crystals but the DPn was only 13. HBPA and HNA were first converted to reactive acyloxyaromatic acid intermediates. Then the DPn was increased by means of reaction-induced crystallization of oligomers and subsequent solid-state polymerization via an acid-ester exchange under nonstoichiometric conditions caused by the monocarboxylic acid by-product. Even though the DPn of PON was not as high, direct polycondensation of HBPA and HNA proceeded successfully with aromatic anhydrides. (C) 2004 Society of Chemical Industry.

    DOI: 10.1002/pi.1728

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  • Morphology of poly(p-oxybenzoyl) prepared in perfluoropolyether Reviewed

    K Kimura, H Ohmori, T Uchida, Y Yamashita

    POLYMERS FOR ADVANCED TECHNOLOGIES   16 ( 1 )   6 - 10   2005.1

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    Solvent effect on the morphology of poly(p-oxybenzoyl) (POB) prepared by the reaction-induced phase separation of oligomers was examined by the polymerization of p-acetoxybenzoic acid in perfluoropolyether Aflunox(TM) (AFL2507 and AFL606). Polymerization was carried out at 320degreesC for 6 hr. POB microspheres were formed in AFL2507 by the liquid-liquid phase separation of oligomers due to the low miscibility of oligomers in AFL2507. The molecular weight of the solvent influenced the morphology, and the polymerization in AFL606 of which the molecular weight was lower than AFL2507 yielded whiskers formed by crystallization of oligomers induced by the increase in miscibility compared with that in AFL2507. The solvent structure and its molecular weight influenced the miscibility of oligomers and ultimately controlled the morphology from whisker to microsphere. Copyright (C) 2004 John Wiley Sons, Ltd.

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  • Alignment of SWNTs in lyotropic rigid-rod polymer compositions

    Thuy D. Dang, Satish Kumar, Tetsuya Uchida, Karla L. Strong, N. Venkatasubramanian

    POLYIMIDES AND OTHER HIGH TEMPERATURE POLYMERS: SYNTHESIS, CHARACTERIZATION AND APPLICATIONS, VOL 3   3   517 - 533   2005

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:VSP BV-C/O BRILL ACAD PUBL  

    Rigid-rod polymeric fibers, fabricated from their lyotropic mesophase in strong acid solutions, are known to have exceptional tensile strength and high stiffness besides exhibiting remarkable thermal and thermooxidative stabilities. Mechanical and electrical properties of Single-Wall Carbon Nanotubes (SWNTs) are also predicted to be quite extraordinary. The potential benefits of reinforcing a rigid-rod polymer, such as P130, with SWNTs as the dispersed phase are demonstrated in this study. The general methodology involves in situ polycondensation to form the rigid-rod polymer in polyphosphoric acid medium in an environment of SWNTs, followed by the dry-jet wet spinning of the hybrid fibers from the lyotropic liquid crystalline solution. The tensile strength of the PBO/SVv'NT fibers incorporating 10 wt% SWNT was found to be 50% higher than that of the control P130 fibers, while only relatively moderate enhancements in the measured values of the tensile modulus and compressive strengths resulted for the hybrid fibers. Morphological studies of the fibers by TEM analysis showed that SWNTs were very well-dispersed in the 90/10 PBO/SWNT heat-treated composite fibers but the presence of SWNT bundles or ropes, 20-50 nm diameter, aligned parallel to the fiber axis, was observed at higher levels of incorporation of SWNTs as was indeed the case for 85/15 PBO/SWNT heat-treated fibers. Recent efforts to effect the sidewall modification of SWNT with phenylbenziraidazole groups to enhance the potential for SWNT dispersion/solubility in acidic media are also discussed.

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  • Processing, structure, and properties of carbon nano fiber filled PBZT composite fiber Reviewed

    T Uchida, T Dang, BG Min, XF Zhang, S Kumar

    COMPOSITES PART B-ENGINEERING   36 ( 3 )   183 - 187   2005

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    The poly(p-phenylene benzobisthiazole) (PBZT)/carbon nano fiber (CNF) composite was prepared by in situ polymerization in polyphosphoric acid (PPA), and fibers spun by dry-jet wet spinning. The liquid crystalline PBZT/CNF dope in PPA exhibited excellent spinnability. The PBZT/CNF weight ratio was 90/10. The transmission electron microscope images show isolated and well oriented CNFs with no aggregation. CNF graphite layer stacking in the composite fiber have been observed using high resolution transmission electron microscopy, and showed that graphitic structure of CNFs was not damaged during polymerization in PPA and subsequent fiber spinning and drawing. High resolution transmission electron microscopy also shows that there is no debonding between CNF and the PBZT matrix. Tensile and compressive properties of the composite fibers have been determined and discussed. (c) 2004 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.compsitesb.2004.04.015

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  • Morphology control of poly(p-mercaptobenzoyl) by modification of oligomer end-group Reviewed

    K Kimura, D Nakajima, K Kobashi, S Kohama, T Uchida, Y Yamashita

    POLYMER JOURNAL   37 ( 7 )   471 - 479   2005

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:SOC POLYMER SCIENCE JAPAN  

    Influence of acyl end-group of oligomers on morphology of poly (p-mercaptobenzoyl) (PMB) was examined by the polymerization of S-acyl-4-mercaptobenzoic acids having the different acyl groups and their dimers in liquid paraffin at 260-300 degrees C. The polymerization of S-acetyl-4-mercaptobenzoic acid afforded PMB whiskers, whereas the polymerization of S-propionyl-4-mercaptobenzoic acid, S-butyryl-4-mercaptobenzoic acid and S-valeryl-4-mercaptobenzoic acid yielded PMB microspheres. The microspheres were formed by the liquid-liquid phase separation of oligomers induced by the longer acyl end-groups than acetyl group of the oligomers due to the reduction of freezing point of oligomers. In contrast to this, the polymerizations of their dimers afforded needle-like and slab-like crystals instead of microspheres. In these polymerizations, the crystallization was induced due to the increase of the molecular weight of the phase-separated oligomers, leading to the increase of the freezing point of oligomers. The morphology of PMB could be controlled by the chemical modification of oligomer end-groups.

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  • Oxidative stabilization of PAN/SWNT composite fiber Reviewed

    BG Min, TV Sreekumar, T Uchida, S Kumar

    CARBON   43 ( 3 )   599 - 604   2005

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:PERGAMON-ELSEVIER SCIENCE LTD  

    PAN/SWNT composite fibers have been spun with 0, 5, and 10wt% single wall carbon nanotubes (SWNTs). Tensile fracture surfaces of polyacrylonitrile (PAN) fibers exhibited extensive fibrillation, while for PAN/SWNT composite fibers, tendency to fibrillate decreased with increasing SWNT content. The reinforcing effect of SWNTs on the oxidized polyacrylonitrile (PAN) fiber has been studied. At 10wt% SWNTs, breaking strength, modulus, and strain to failure of the oxidized composite fiber increased by 100%, 160%, and 115%, respectively. Tensile fracture surfaces of thermally stabilized PAN and the PAN/SWNT fibers exhibited brittle behavior and well distributed SWNT ropes covered with the oxidized matrix can be observed in the tensile fracture surfaces of the fibers. No de-bonding has been observed between unoxidized or the oxidized PAN matrix and the nanotube ropes. Higher strain to failure of the oxidized composite fiber as compared to that of the oxidized control PAN fiber also suggests good adhesion/interaction between SWNT and the oxidized matrix. Thermal stresses generated on the composite fiber during the oxidation process were lower than those for the control fiber. The potential of PAN/SWNT composite fiber as the precursor material for the carbon fiber has been discussed. (C) 2004 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.carbon.2004.10.034

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  • Crystal structure and composition of poly(ethylene terephthalate-co-4,4 '-bibenzoate) Reviewed

    HM Ma, T Uchida, DM Collard, DA Schiraldi, S Kumar

    MACROMOLECULES   37 ( 20 )   7643 - 7648   2004.10

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    The crystal structure in random copolymers poly(ethylene terephthalate-co-4,4'-bibenzoate) (PET/BB) was studied using wide-angle X-ray diffraction (WAXD). The composition of crystalline and amorphous regions has been studied by FTIR spectroscopy using the amorphous peaks at 1580 and 1560 cm(-1) for terephthalate (T) and bibenzoate (B) units, respectively. Further, PET/BB55 was hydrolyzed to selectively etch the amorphous regions. The hydrolyzed products were further studied by FTIR and H-1 NMR spectroscopy, wide-angle X-ray diffraction, and transmission electron microscopy. Results show that crystal structures are very close to that of the respective homopolymer, PET and poly(ethylene bibenzoate) (PEBB) for the low and high BB content samples, respectively. The crystalline region of high BB content fibers is composed of mainly PEBB units. In PET/BB55 fiber, among the 30 wt % of the copolymer which was not etched, there is only one terephthalate unit for every five repeat units of bibenzoate. The crystal size of B type crystals along the c axis was found to be around five repeat units long. Short chain segments rich in BB are sufficient to induce crystallization, to form PEBB-like crystals.

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  • Fractionation and crystal morphology of rigid polymer, poly(p-phenylene benzobisthiazole) Reviewed

    K Shimamura, N Michiaki, T Ikeda, T Uchida, M Hirao

    JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS   B43 ( 5 )   1015 - 1024   2004.9

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:MARCEL DEKKER INC  

    Fractionation of the rigid polymer, poly(p-phenylene benzobisthiazole) (PBZT), was carried out in dilute solution in concentrated methane sulfuric acid (MSA) using silica gels as packing material of a column. Several combinations of the average chain length of the fractionating materials and the average pore diameter of the gels were examined to improve fractionation resolution. The gels with average pore diameter near the average chain length resulted in high fractionation resolution. Single crystals of the fractionated and unfractionated PBZTs were observed by transmission electron microscopy (TEM). Both single crystals were fundamentally composed of rod crystals with the chain orienting normal to the rods. The unfractionated PBZT made a cluster of parallel rod crystals, where longer chains penetrated a few rod crystals leaving their chain ends within the crystalline core. On the contrary, with the fractionated polymer, extended-chain rod-like crystals were dispersed, isolated from each other. This morphology enables us to estimate the chain length visibly by TEM, for which a few milligrams of the material is enough for the observation.

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  • Preparation of poly(p-oxybenzoyl) microspheres having needlelike crystals on the surface Reviewed

    K Kimura, S Kohama, S Kondoh, Y Yamashita, T Uchida, T Oohazama, Y Sakaguchi

    MACROMOLECULES   37 ( 4 )   1463 - 1469   2004.2

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    Polymerization of 4-acetoxybenzoic acid (ABA) with 3,5-diacetoxybenzoic acid (DABA) was examined to create a novel morphology of poly(p-oxybenzoyl) (POB) by means of the phase separation of oligomers during polymerization. Polymerizations were carried out at a concentration of 1.0% in liquid paraffin at 320 degreesC. Polymerization of ABA yielded the POB whiskers. On the other hand, the polymerization of ABA with DABA of which the concentration in the feed (chi(f)) was 0.05-0.20 yielded the microspheres having needlelike crystals on the surface. The average diameter of the microspheres was in the range of 3.4-1.6 mum and the average length of the needlelike crystals was 3.2-0.3 mum. The diameter and length decreased with chi(f). DABA acted as a liquid-liquid phase separation inducer and the liquid-liquid phase separation of co-oligomers comprising 4-oxybenzoyl units and 3,5-dioxybenzoyl units was induced in the beginning of polymerization to form the core microspheres. Then the phase separation mode was changed to the crystallization of the homooligomers of the 4-oxybenzoyl unit and the homooligomers were crystallized as needlelike crystals on the surface of microspheres already precipitated. Solid-state polymerization occurred in the precipitates. The microspheres having needlelike crystals were prepared by the combination of liquid-liquid phase separation and the crystallization of oligomers during solution polymerization. The obtained microspheres having needlelike crystals possessed very high crystallinity and exhibited good thermal stability.

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  • Diameter control of poly(p-oxycinnamoyl) microspheres prepared by self-organizing polycondensation Reviewed

    K Kimura, S Kohama, Y Yamashita, T Uchida, Y Sakaguchi

    POLYMER   44 ( 24 )   7383 - 7387   2003.11

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    The diameter control of poly(p-oxycinnamoyl) (POC) microspheres was examined. POC microspheres were prepared by the polycondensation of (E)-4-acetoxycinnamic acid in liquid paraffin at 320 degreesC. The microspheres were formed through the formation of microdroplets by the reaction-induced liquid-liquid phase separation and the subsequent polymerization of oligomers in the microdroplets leading to the solidification. The size of the microspheres was actually governed by the coalescence of the microdroplets in the growth process. In order to control the coalescence of the microdroplets, 4-octadecyloxybiphenyl (ODB) was added to the polymerization solution as a coalescence inhibitor, which exhibited amphiphilicity to liquid paraffin and POC. ODB inhibited the coalescence of the microdroplets. The average diameter decreased with the increase of the ODB concentration, and it was tunable from 0.97 to 4.61 mum. (C) 2003 Elsevier Ltd. All rights reserved.

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  • Preparation and mechanical properties of rigid polymer network/nylon6 composites Reviewed

    T Uchida, K Shimantura, K Kimura

    SEN-I GAKKAISHI   59 ( 6 )   207 - 212   2003.6

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:SOC FIBER SCIENCE TECHNOLOGY  

    Rigid polymer networks were prepared by polycondensation of 2,5-diamino-1,4-benzenedithiol with a mixture of tereplithalic acid (TPA) and trimesic acid (TMA). The apparent density was dependent on TPA/TMA ratio and much less than that of linear PBZT (1.57 g/cm(3)), showing existence of many nano voids within the network. As the segment was so rigid, many COOH's were left around the voids. The network swelled twice in weight with E caprolactam, which was polymerized into a composite form of nylon6 impregnated rigid polymer network. Extraction of free nylon6 from the composite with formic acid showed that a quarter of nylon6 grafted directly to rigid polymer network. The grafted nylon6 could not crystallize evidenced by DSC measurements. On the other hand, particles of PBZT network (several hundred nm in diameter) were prepared by stopping the polycondensation just before gelation. A composite film was prepared with the particles swollen with epsilon-caprolactam. The ratio of PBZT network/nylon6 was 1/3 and the apparent density of the composite film was 1.23 g/cm(3) which is higher than that of a pure nylon6 film (1.16 g/cm(3)). Significant improvement in the mechanical property was observed for this composite.

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  • Self-assembling polycondensation for preparation of poly(p-oxybenzoyl-alt-p-mercaptobenzoyl) whisker Reviewed

    K Kobashi, K Kimura, Y Yamashita, T Uchida, Y Sakaguchi

    MACROMOLECULES   36 ( 12 )   4268 - 4275   2003.6

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    Self-assembling polycondensation was examined to prepare the whisker of poly(p-oxybenzoyl-alt-p-mereaptobenzoyl). Polymerizations were carried out in liquid paraffin (LPF) and aromatic solvents such as Therm S 800 and 1000 at 300 degreesC for 6 h. Polymerization concentration was 1.0 wt/vol %. The whisker was not obtained by the random copolymerization of p-acetoxybenzoic acid and S-acetyl-4-mercaptobenzoic acid at the molar ratio of 0.5 in feed. However, the whiskers were successfully prepared by the polymerization of S-(4-acetoxybenzoyl)-4-mercaptobenzoic acid (OS) and 4-(S-acetyl-4-mercaptobenzoyl)oxybenzoic acid (SO). The whisker prepared from OS (POS) in LPF was 18 mum in average length and 0.4 mum in average width, and that from SO (PSO) was slightly longer than POS. The whiskers prepared in aromatic solvents were much longer than those in LPF, for which the length was 36-49 mum. These whiskers consist of the alternating polymer chains, and the polymer chains align along the long axis of the whisker. The sequence regularity enhanced the crystallizability of the oligomers, and this led to the formation of whiskers. The oligomer formation rate was much higher than that of transesterfication reaction rate, and this large difference in these two rates made the oligomer precipitate with maintaining the alternating sequence. Further polymerization occurred in the crystals, and the whiskers having the alternating sequence were finally completed. The difference in the two rates increased with the decrease of the miscibility between the oligomer and the solvent, and therefore, OS and LPF were more advantageous to maintain the alternating sequence.

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  • Electrooxidation of alcohols in a disperse system with N-oxyl-immobilized polyethylene particles as disperse phase and aqueous NaHCO3/NaBr as disperse media: A totally closed electrolysis system Reviewed

    H Tanaka, J Kubota, S Itogawa, T Ido, M Kuroboshi, K Shimamura, T Uchida

    SYNLETT   7 ( 7 )   951 - 954   2003.6

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:GEORG THIEME VERLAG KG  

    Electrooxidation of alcohols was performed successfully in a disperse system with N-oxyl immobilized polyethylene particles as disperse phase and an aqueous saturated NaHCO3 solution involving 20 wt% NaBr as disperse media. The N-oxyl immobilized polyethylene particles were prepared by heating a suspension of polyethylene particles (3 x 3 x 0.02 mm(3)) in fuming nitric acid at 80 degreesC for 1 h followed by treatment with 4-amino-2,2,6,6-tetramethylpyperidine- 1-oxyl in chlorobenzene in the presence of DCC. Recycle use of the N-oxyl-immobilized polyethylene particles and the aqueous media was performed successfully without significant change of the yields of the products and current efficiency, thereby offering a totally closed electrolysis system.

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  • 剛直高分子三次元架橋体およびその複合体の構造と物性 Reviewed

    内田 哲也, 島村 薫, 木村邦生

    繊維学会誌   59 ( 6 )   207 - 212   2003

  • Poly(ethylene-block-vinylalcohol) film with amphiphilic surface at high temperature Reviewed

    K Shimamura, Y Munesawa, T Uchida, N Hikasa

    POLYMERS FOR ADVANCED TECHNOLOGIES   13 ( 3-4 )   205 - 209   2002.3

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    Poly(ethylene-block-vinylalcohol) (PE/PVA), which consisted of both hydrophobic and hydrophilic blocks, was prepared by using polyethylene single crystals as starting material. Polyethylene single crystals were reacted with fuming nitric acid resulting in long methylene chains with functional groups such as COOH and NO? at the ends (the chain lengths were almost the same as the lamellar thickness of polyethylene single crystal). The functionalized methylene chains were allowed to react with 4-aminostyrene to give corresponding amides, i.e. methylene chains with vinyl groups at the ends (macromer). The macromers were extended by block-copolymerization with vinyl acetate, then saponified resulting in PE/PVA block copolymer.
    The block copolymer was molded into sheets which were subsequently heat-treated in contact with hydrophilic or hydrophilic media. Depending on the media, the sheet surface changed at high temperature reversibly from hydrophilic to hydrophobic and vice versa. Die surface property was fixed by quenching because both blocks were able to crystallize. Thus the surface of this material can be tailored for various purposes at high temperature, and then used in stable condition at room temperature. Copyright (C) 2002 John Wiley Sons, Ltd.

    DOI: 10.1002/pat.174

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  • Observation of a solitary rigid molecular chain cilium standing on poly(p-phenylene benzobisthiazole) lamellar crystal Reviewed

    K Shimamura, T Uchida

    JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS   B41 ( 3 )   529 - 537   2002

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    The rigid polymer, poly(p-phenylene benzobisthiazole), crystallized from H2SO4, formed a lamellar crystal in which the polymer chains were oriented perpendicular to the lamellae. It was supposed that the lamellar surface bristled with chain cilia because of wide distribution in the polymer chain length. This region of the bristle would be a transitional structure from full to deficient packing of the polymer chains. Ordinary scanning probe microscopy of the bristled lamellar surface permitted depiction of a layer with a constant population of the cilia. In this work, the method for imaging one single polymer chain end standing on the lamellar surface was developed. From the image it was concluded that an isolated, long cilium did not move extensively at room temperature. In addition, the three-dimensional chain end distribution was determined by several tens of scannings with consecutively varying input energy of the cantilever.

    DOI: 10.1081/MB-120004351

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  • Polymer supported N-Oxyl mediated electrooxidation of alcohols in aqueous NaBr/NaHCO3 Reviewed

    H Tanaka, M Kuroboshi, J Kubota, S Itogawa, T Ido, T Uchida, K Shimamura

    REACTIVE INTERMEDIATES IN ORGANIC AND BIOLOGICAL ELECTROCHEMISTRY   2001 ( 14 )   17 - 20   2001

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    Electrooxidation of alcohols 1 was performed successfully in an aqueous disperse system with N-Oxyl-immobilized polyethylene particles (PE-N-Oxyl) as the disperse phase and an aqueous saturated NaHCO3 containing 20 wt.% of NaBr as the disperse media. Work-up process is quite simple; thus, polymer perticles were separated by filtration and washing with EtOAc and the filtrate and the washings were combined, extracted with EtOAc, dried (Na2SO4) and concentrated in vacuo to afford the corresponding ketones 2. The recovered PE-N-Oxyl as well as the aqueous disperse media could be repeatedly used for the electrooxidation of 1 without significant change of the yields of the ketones 2.

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  • Whisker of poly(p-oxybenzoyl-co-p-mercaptobenzoyl) - Influence of sequence on polymer morphology Reviewed

    K Kimura, D Nakajima, K Kobashi, Y Yamashita, F Yokoyama, T Uchida, Y Sakaguchi

    POLYMERS FOR ADVANCED TECHNOLOGIES   11 ( 8-12 )   747 - 756   2000.8

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    Aromatic polymers are expected to possess outstanding properties. However in many cases they do not show good processability because of their chain regidity. We have been studying the morphology control of rigid polymers during polymerization to overcome this problem and succeeded in preparing the whiskers of poly (p-oxybenzoyl) and poly (p-mercaptobenzoyl) by the polymerization in liquid paraffin at around 300 degreesC. These whiskers are formed by the reaction induced crystallization of oligomers during solution polymerization.
    The preparation of copolymer whiskers is very interesting to design the new materials which are endowed with novel functions. The aim of this study is to prepare the whisker of poly (p-oxybenzoyl-co-p-mercaptobenzoyl) and to clarify the influence of the copolymerization on the morphology, especially focusing on the sequence regularity. The introduction of comonomer unit into polymer chain structure extinguishes the crystal habit due to the lower crystallizability and the whiskers can be obtained by the random copolymerization of 4-acetoxybenzoic acid (ABA) and S-acetyl-4-mercaptobenzoic acid (AMBA) only when chi (f) (the molar ratio of ABA/AMBA in feed) is 1.0-0.7 and 0.05-0. However, the copolymer whiskers are obtained by the polymerization of OS, OOS and SSO monomers which produce the alternating and periodic copolymers. These copolymer whiskers consist of the alternating or periodic copolymer chains and their chains align along the long axis of the whisker. The sequence regularity enhances the crystal lizability of cooligomers and this lends to the formation of the whiskers. The sequence regularity in copolymers is a very influential parameter to control the morphology and the copolymer whiskers can be prepared by giving the regular sequences. Copyright (C) 2000 John Wiley & Sons, Ltd.

    DOI: 10.1002/1099-1581(200008/12)11:8/12<747::AID-PAT53>3.0.CO;2-4

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  • Super structure formation in a wholly aromatic copolyester fiber Reviewed

    Tetsuya Uchida, Kaoru Shimamura

    Polymers for Advanced Technologies   11 ( 4 )   198 - 202   2000.4

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    The structure of a wholly aromatic copolyester fiber containing 60 mol% p-hydroxybenzoic acid (PHB), 20 mol% 4-4'-dihydroxydiphenyl, 15 mol% terephthalic acid and 5 mol% isophthalic acid was studied by means of electron microscopy and wide-angle X-ray diffraction. The X-ray diffraction pattern of the wholly aromatic copolyester fibers showed two sets of diffractions: one set was composed of sharp spots which arose from relatively high crystalline phase. The crystal structure analyzed by these spots was orthorhombic and the lattice dimensions were a = 0.869 nm, b = 0.510 nm, c = 1.20 nm and ρ = 1.50 g/cm3. Another set was characteristic of streaks on the meridian extending parallel to the equator. X-ray scattering intensity distribution on the meridian was calculated as the square of Fourier transform of random chain model. Comparison of this intensity distribution with the observed meridional maxima concluded that the streaks were due to rather disordered chains with a PHB content of less than 50%. Dark field image (DFI) taken from the meridional 002 reflection showed that slender crystallites were distributed over the whole visual field, oriented parallel to the fiber axis. On DFI from the equatorial 200 reflection, some of these crystallites were also observable, forming groups that distributed randomly in the field. All crystallites belonging to the same group co-oriented in a(*)- and c(*)-axis directions, though disordered parts intervened among the crystallites. This is attributed to the fact that, though the content of PHB in the segments of disordered parts was only 50%, these PHB held the co-orientation among the slender crystallites within one group. Heat treatment induced the development of block segment and subsequent crystallite growth with fiber. This reorganization improved the thermostability and the mechanical properties. Copyright (C) 2000 John Wiley and Sons, Ltd.

    DOI: 10.1002/1099-1581(200004)11:4<198::AID-PAT970>3.0.CO;2-1

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  • Morphology and structure of poly(p-phenylene benzobisthiazole) crystals Reviewed

    K Shimamura, T Uchida

    JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS   B39 ( 5-6 )   667 - 677   2000

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    The rigid polymer poly(p-phenylene benzobisthiazole) (PBZT) was crystallized from dilute solution. Electron microscopy showed that, on quenching, flat fibrils several nanometers thick were produced. Subsequent heat treatment in a solvent changed the morphology from fibrillar into "segmented ribbon" structure. Isothermal crystallization at a temperature of about 30 degreesC below the dissolution temperature, in general, resulted in aggregation of rod crystals. The polymer chains were oriented normal to the rod crystals. The width of the rod crystal increased with average molecular length, but saturated to a value much smaller than the average molecular length. In the shorter molecular length range, the rod crystals clustered in a fanned-out manner, while with a medium molecular length (ca. 70-120 nm), all rods crystals in a cluster aligned parallel to each other and were of the same length. With longer molecular length (more than ca. 180 nm), the rod growth slowed because of small diffusion constants of molecular chains to the growing face. Based on observation of the morphology and the crystallization process, an isothermal crystallization mechanism is proposed. Because of the rigidity and wide length distribution of polymer chains, the chain ends were inevitably included within the crystals, resulting in crystal defects such as axial shifts, lattice curvatures, and edge dislocations, all of which were observed directly by lattice imaging.

    DOI: 10.1081/MB-100102478

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  • 高密度ポリエチレンインフレーションフィルムの構造 Reviewed

    村上昌三, こうじ谷信三, 内田哲也, 島村 薫

    高分子論文集   56 ( 12 )   828 - 831   1999

  • Crystallization of poly (p-phenylene benzobisoxazole) from dilute solution Reviewed

    Kaoru Shimamura, Tetsuya Uchida, Makoto Suzuki, Chunxiao Zhang

    Sen'i Gakkaishi   54 ( 7 )   374 - 378   1998

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    PBZO's having average molecular length of 27,49 and 128 nm were crystallized from dilute solution in conc.H2SO2. At high crystallization temperature, the shorter PBZO (L∼30nm) formed lath shaped lamellar crystals. Electron diffraction indicated that the long axis of the lamella to be along the crystallographic b-axis forming 100 twins, and that the molecular chains was perpendicular to the lamella. High resolution electron micrograph showed that 100 lattice fringe had an orientation distribution and curved within one crystallite. Decrease in crystallization temperature and/or increase in the chain length changed the morphology essentially into flat fibrils. Branchings through repetitive twinning across {100} and [formula-ommited] planes lead to a square network. Vacancies in the fibrillar network were finally filled by post lamellar growth resuting in a mosaic structure, except with PBZO of the longest molecular chain. Oriented rigid cilia on the lamellar surface facilitated the growth rate of daughter crystals and regulated their orientation. © 1998, The Society of Fiber Science and Technology, Japan. All rights reserved.

    DOI: 10.2115/fiber.54.7_374

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  • Branched Poly(p-phenylene benzobisthiazole) Crystallized from Dilute Solution Reviewed

    Kaoru Shimamura, Michio Ishitobi, Tetsuya Uchida, Makoto Suzuki

    sen'i gakkaishi   50 ( 3 )   101 - 104   1994

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    Poly(p-phenylenebenzobisthiazole) P (PBZT) chains with average molecular length of 61 nm have been reacted with trimesic acid to link each other. The product, a mixture of Y-, V-shaped and linear P (PBZT)'s, was dissolved into conc.SCU at a concentration of 0.1 wt%, and isothermally crystallized. The precipitate was composed essentially of curved rod-like crystals. Four or five crystals having different length coagulated each other with many branches at an angle of ca 60°. This morphological feature was in contrast to that of pure linear P (PBZT) precipitate in which several tens straight rod-like crystals of the same length were oriented parallel to each other to make a group. This difference in morphology between linear P (PBZT) and the mixture of Y, and V-shaped and linear P (PBZT)'s was well explained by the crystallization mechanism of P (PBZT). 100 lattice fringe was observed throughout the central area of the rod-like crystal. This means that the center was composed of linear part of Y-, V-shaped and linear polymers, which were accomodated normal to the rod. In some area, the 001 lattice fringe crossed 100 lattice fringe at an angle of ca 75°, suggesting that P (PBZT) unit cell might not be Fratini's monoclinic type. On both sides of the 100 lattice fringe, there were dark belts. These belts corresponded to thick parts which were composed of the other counterparts in the Y- and V-shaped poly mers. © 1994, The Society of Fiber Science and Technology, Japan. All right reserved.

    DOI: 10.2115/fiber.50.3_101

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  • 日経BP テクノロジーロードマップ 2019-2028 医療・健康・食農編

    内田哲也( Role: Joint author ,  第2章 人工網膜)

    日経BP  2019 

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  • ナノファイバーの製造・加工技術と応用事例

    内田哲也( Role: Joint author ,  第4章 第3節 希薄溶液からの結晶化を利用した新規ナノファイバーの作製と複合体への応用)

    技術情報協会  2019 

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  • セルロースナノファイバー ~実用化に向けた製造・複合化・評価技術~

    内田哲也( Role: Joint author ,  第2章 第7節 高分子結晶での被覆によるセルロースナノファイバーの表面改質)

    情報機構  2018 

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  • セルロースナノファイバーの均一分散と複合化

    内田哲也( Role: Joint author ,  第2章第4節 高分子結晶での被覆によるセルロースナノファイバーの疎水化と複合体への応用)

    サイエンス&テクノロジ  2018 

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  • 樹脂/繊維複合材料の界面制御、成形加工と評価

    内田哲也( Role: Joint author ,  第4章5節 高分子結晶での被覆によるセルロースナノファイバーの分散性向上と複合体フィルムへの応用)

    技術情報協会  2018 

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  • 高熱伝導性樹脂の設計・開発

    内田哲也( Role: Joint author ,  第Ⅲ編 高分子の高熱伝導化 第6章 単層カーボンナノチューブの凝集構造制御と複合体への応用)

    シーエムシー出版  2016 

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  • セルロースナノファイバーの実用化技術

    S&T出版  2016 

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  • American Society for Composites Series on Advances in Composite Materials 2

    H.G.Chae, X.Zhang, B.Min, T.Liu, T.V.Sreekumar, T.Uchida, S.Kumar( Role: Joint author ,  Polymer/carbon nanotube composites: challenges and opportunities.)

    American Society for Composites  2012 

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  • Nanoengineering of Structural, Functional and Smart Materials

    CRC press, Florida USA  2006 

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MISC

  • 第1編 第5章 第1節 高分子結晶での被覆によるセルロースナノファイバーおよびセルロースナノクリスタルの表面改質と複合体への応用

    内田哲也

    セルロースナノファイバー 研究と実用化の最前線   2021.11

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  • 第Ⅱ編 第5章 高分子結晶での被覆によるCNF・CNCへの分散性付与

    内田哲也

    ナノカーボン・ナノセルロースの分散・配向制御技術   2021.11

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  • 32.色素結合薄膜型人工網膜: 失われた視覚を人工網膜で取り戻す

    松尾俊彦, 内田哲也

    日経メディカル   641   52 - 52   2021.4

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  • 11 人工網膜

    松尾俊彦, 内田哲也

    日経BP テクノロジー・ロードマップ 2021-2030 医療・健康・食農編   226 - 229   2021

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  • Photoelectric Dye-Based Retinal Prosthesis (OUReP) as a Novel Type of Artificial Retina

    T. Matsuo, T. Uchida

    Intern. Med. Review   7   1 - 17   2021

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  • 色素結合薄膜型の人工網膜OUReP(オーレップ)

    松尾俊彦, 内田哲也

    光アライアンス   31 ( 7 )   13 - 18   2020

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  • 簡便な温度制御で、エンプラをナノファイバー化 高分子結晶を表面に被覆、CNFの分散性向上

    内田哲也

    コンバーテック   48 ( 3 )   71   2020

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  • オール岡山の技術が光を取り戻す! -いよいよ最終段階に来た人工網膜とは

    松尾俊彦, 内田哲也

    OPTRONICS   39 ( 7 )   124 - 129   2020

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  • 希薄溶液からの結晶化を利用した高性能高分子ナノ材料の作製と複合体への応用

    内田哲也

    コンバーテック   ( 10 )   75 - 81   2018

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  • 希薄溶液からの結晶化を利用した高性能ナノファイバーの創製と複合体への応用

    内田哲也

    繊維学会誌   74   489 - 492   2018

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  • 希薄溶液からの結晶化を利用した新規ナノファイバーの作製と高性能高分子材料への応用

    内田哲也

    繊維機械学会誌   71   233 - 238   2018

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  • 特集「高機能フィルム・シートと製造技術 」ポリエチレンフィルムを利用した人工網膜の実用化に向けて<色素固定薄膜型人工網膜(OURePTM)の実用化に向けた医工連携研究>

    内田哲也, 松尾俊彦

    プラスチックス 2017年3月号   2017

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  • セルロースナノファイバーの高分子結晶での被覆と複合体への応用

    内田哲也, 岩畔史明, 矢内梨沙, 童銅はる香

    加工技術   52   85 - 91   2017

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  • いちょう並木 岡山大学広報誌 2016年6月 No.81 岡山大学が誇る!注目の最先端研究「医工連携で、新方式の人工網膜を開発 光を失った患者に、新たな”光”を届ける」

    松尾俊彦, 内田哲也

    いちょう並木   81   5 - 6   2016

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  • 岡山医学会雑誌「色素結合薄膜型(岡山大学方式)の人工網膜(OUReP)の医師主導治験」

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    岡山医学会雑誌   127 ( 3 )   223 - 229   2015

  • 剛直高分子をナノ材料化する古くて新しい方法~希薄溶液からの結晶化を利用した剛直高分子ナノファイバーの作製と応用~

    内田哲也

    50   323 - 328   2015

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  • 人工臓器「第52回日本人工臓器学会大会 論文賞(広領域)受賞レポート」

    阿拉木斯, 松尾俊彦, 細谷修, 筒井公子, 内田哲也

    人工臓器   44 ( 1 )   16 - 17   2015

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  • 両備てい園記念財団「色素結合薄膜型の人工網膜(OUReP)の医師主導治験を目指して」

    松尾俊彦, 内田哲也

    生物学に関する試験論叢   30   117 - 123   2015

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  • Okayama University Medical Research Updates (OU-MRU) Vol. 7 "Researchers at Okayama demonstrate the promise of a new approach for stimulating neurons in the eyes of patients with dead photoreceptor cells."

    Toshihiko Matsuo, Tetsuya Uchida

    Okayama University Medical Research Updates (OU-MRU) Vol. 7   7   2015

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  • 希薄溶液からの結晶化を利用した新規ナノファイバーの作製と高性能高分子材料への応用

    内田哲也, 古川 勉, 岩畔史明, 童銅はる香

    ケミカルエンジニアリング   60   547 - 554   2015

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  • アラミドの中空微粒子の新調整法 (特集 革新的先進材料の開発と応用)

    木村 邦生, 山崎 慎一, 内田 哲也

    ケミカルエンジニヤリング = Chemical engineering   59 ( 12 )   893 - 897   2014.12

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  • 色素固定薄膜型人工網膜(岡山大学方式人工網膜)の実用化に向けた医工連携の取り組み

    内田哲也, 松尾俊彦

    機能材料   34 ( 5 )   41 - 47   2014

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  • 色素結合薄膜型の人工網膜(OURePTM)の医師主導治験を目指して

    松尾俊彦, 内田哲也

    人工臓器   43 ( 4 )   189 - 193   2014

  • 人工臓器「第51回日本人工臓器学会大会 Tominaga Award 2012受賞レポート」

    阿拉木斯, 松尾俊彦, 細谷修, 筒井公子, 内田哲也

    人工臓器   43 ( 1 )   31 - 32   2014

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  • アラミドの中空微粒子の新調製法 Invited

    木村邦生, 山崎慎一, 内田哲也, 中山博文

    ケミカルエンジニヤリング   59 ( 12 )   1   2014

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  • Okayama University e-Bulletin "Intellectual Property and Enterprise" Photoelectric dye-coupled thin film as a novel type of retinal prosthesis.

    Toshihiko Matsuo, Tetsuya Uchida

    Okayama University e-Bulletin Vol. 8, 2014   8   2014

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  • Preparation of High-Performance Polymer Spheres by Using Phase-Separation During Solution Polymerization

    Kunio Kimura, Shinichi Yamazaki, Tetsuya Uchida

    Proc. Society for the Advancement of Material and Process Engineering Symposium   44   11   2012

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  • 電子顕微鏡でみる単層カーボンナノチューブ(SWNT)/高分子複合体繊維およびSWNT単結晶の微細構造とその構造制御

    内田哲也, 津川直矢, 赤石卓也

    繊維学会誌   67 ( 5 )   131 - 134   2011

  • Preparation of Poly(p-phenylene pyromelliteimide) Needle-like Crystal

    Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

    The 10th Asian Textile Conference Proceedings   2009

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  • Morphology and Structure of Single-walled Carbon Nanotube Bundles, Single Crystals and Composite Fibers

    Tetsuya Uchida

    2009 Japanese-Sino Fiber symposium proceedings   2009

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  • POLY 507-Fabrication of nanoribbon of high-performance polyimide

    Kanji Wakabayashi, Shinichi Yamazaki, Tetsuya Uchida, Kunio Kimura

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   235   507   2008.4

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  • Nanoribbon of poly(4-phthalimide) prepared by crystallization of oligomers

    Kanji Wakabayashi, Shinichi Yamazaki, Tetsuya Uchida, Kunio Kimura

    International Symposium on Polymer Crystallization, ISPC07, Proceedings   29   2007

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  • Morphology control of poly(p-mercaptobenzoyl) by modification of oligomer end-group.

    K Kimura, D Nakajima, K Kobashi, S Kohama, Y Yamashita, T Uchida

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   229   U949 - U949   2005.3

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  • Morphology of poly(p-oxycinnamoyl) formed by hydrodynamically induced crystallization during solution polymerization.

    K Kimura, M Muraoka, Y Yamashita, T Uchida

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   229 ( 1 )   U949 - U950   2005.3

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  • Transmission electron microscopy studies in single wall carbon nanotube/polymer composite fibers Reviewed

    T Uchida, S Kumar

    PROCEEDINGS OF 2005 INTERNATIONAL CONFERENCE ON ADVANCED FIBERS AND POLYMER MATERIALS (ICAFPM 2005), VOL 1 AND 2   655 - 659   2005

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    Dispersion and exfoliation of single wall carbon nanotubes (SWNTs) have been studied in poly(acrylonitrile) (PAN), poly(p-phenylene benzobisoxazole) (PBO) solutions, and composite fibers using transmission electron microscopy. Close observation of the SWNT/PAN (5/95) composite fibers revealed that as a result of polymer assisted dispersion and exfoliation, the average SWNT bundle diameter in SWNT/PAN (5/95) was 11 nm, while the average diameter for the pristine SWNT bundles was about 30 nm. In addition, high resolution TEM of SWNT/PBO (10/90) composite fibers did not reveal the presence of SWNT aggregates or bundles, suggesting SWNT exfoliation as individuals. On the other hand, both oriented and unoriented nanotube bundles have been observed in SWNT/PBO samples containing 15 wt % nanotubes.

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  • Morohology Control of Poly(p-mercaptobenzoil)by Modification of Ologomer End-group

    K.Kimura, D.Nakajima, K.Kobashi, S.Kohama, T.Uchida, Y.Yamashita

    Polymer Preprints   46 ( 1 )   694 - 695   2005

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  • Polymer/carbon nanotube composites: Challenges and opportunities.

    S Kumar

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   227   U475 - U475   2004.3

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  • POLYMER/CARBON NANO FIBER COMPOSITE FIBERS

    Satish Kumar, Tetsuya Uchida, Thuy Dang, Xiefei Zhang, Young-Bin Park

    Society for the Advancement of Material and Process Engineering Symposium Proceedings, Vol.49 “Materials and Processing Technology” (2004)   49   1229 - 1240   2004

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  • Electrooxidation of alcohols in an n-oxyl immobilized rigid polymer particles disperse water system.

    Tanaka, Hideo, Ido, Toru, Kubota, Jun, Kuroboshi, Manabu, Uchida, Tetsuya, Shimamura, Kaoru

    Proceedings - Electrochemical Society   12   65 - 68   2003

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  • REFINED STRUCTURE OF PHENAZINE-IODINE MOLECULAR-COMPLEX, C12H8N2.I2 Reviewed

    T UCHIDA, K KIMURA

    ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS   40 ( JAN )   139 - 140   1984

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    Language:English   Publisher:MUNKSGAARD INT PUBL LTD  

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Presentations

  • Preparation of Cellulose Nanofibers Coated with Poly(vinyl alcohol) Crystals and their Application to Composite Films

    Risa Yanai, Fumiaki Iwaguro, Haruka Dodo, Ryota Yabune, Tetsuya Uchida

    5th Asian Textile Conference (ATC-15)  2019.9 

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    Language:English   Presentation type:Oral presentation (general)  

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  • 高性能高分子ナノ材料の作製と複合体への応用-新手法での構造制御による極限材料の開発- Invited

    内田哲也

    ファインケミカルジャパン2018  2018.4.19 

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    Language:Japanese   Presentation type:Oral presentation (invited, special)  

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  • Preparation of Rigid Polymer Nanofiber and Nanosheet by using Crystallization from Dilute Solution and its application to composite films (Keynote Lecture) Invited

    T.Uchida

    14th Asian Textile Conference (ATC-14)  2017.6 

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  • 高性能高分子ナノ材料 -新手法での構造制御による極限材料の開発-

    nanotech2015  2015 

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  • Preparation of Helical Crystals of Poly(ester-imide) by Crystallization during Polymerization - Influence of Oligomer Structure on Helical Morphology

    13th ASIAN TEXTILE CONFRENCE  2015 

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  • Preparation of rigid polymer nanofiber by using crystallized from dilute solution and its application

    13th ASIAN TEXTILE CONFRENCE  2015 

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  • 単層カーボンナノチューブを核材として利用した剛直高分子の結晶化および結晶形態

    高分子学会中国四国支部若手研究会  2012 

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  • 希薄溶液からの結晶化を利用したSWNTの凝集構造制御およびその微細構造電子顕微鏡観察

    平成24年度高分子学会  2012 

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  • 重合相変化を利用したポリイミダゾピロロン微粒子の調製

    平成24年度高分子学会  2012 

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  • 共重合を利用したポリエステルイミド結晶のらせん構造制御

    平成24年度高分子学会  2012 

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  • 光電変換色素固定ポリエチレン薄膜の人工網膜への応用と表面電位光応答性に関する研究

    平成24年度繊維学会年次大会  2012 

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  • 剛直高分子三次元架橋体フィルムの作製

    平成24年度繊維学会年次大会  2012 

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  • 単層カーボンナノチューブナノフィラーの作製とポリビニルアルコールとの複合体への応用

    平成24年度繊維学会秋季研究発表会  2012 

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  • 希薄溶液からの結晶化により作製した単層カーボンナノチューブ結晶の微細構造電子顕微鏡観察

    平成24年度繊維学会秋季研究発表会  2012 

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  • 光電変換色素固定ポリエチレン薄膜の表面電位光応答性

    平成24年度繊維学会秋季研究発表会  2012 

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  • 重合相変化を利用したポリ(p-オキシベンゾイル)ネットワーク構造体の創製-非紡糸調製法による高性能不織布の開発-

    平成24年度繊維学会年次大会  2012 

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  • 単層カーボンナノチューブを用いたナノフィラーの作製と複合体への応用

    平成24年度繊維学会年次大会  2012 

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  • 重合相変化を利用した芳香族ポリエステルイミド結晶のらせん形態制御

    平成24年度繊維学会夏季セミナー  2012 

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  • 重合相変化を利用した芳香族ポリエステルの不織布の調製

    平成24年度繊維学会夏季セミナー  2012 

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  • 単層カーボンナノチューブを核材として利用した剛直高分子の結晶化および結晶形態

    H24年度高分子学会高分子討論会  2012 

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  • 重合相変化を利用したアラミド中空微粒子の調製

    平成24年度繊維学会夏季セミナー  2012 

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  • 単層カーボンナノチューブ(SWNT)をナノフィラーとして用いたPVA/SWNTフィルムの作製

    H24年度高分子学会高分子討論会  2012 

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  • 剛直高分子三次元架橋体の合成とフィルムの作製

    H24年度高分子学会高分子討論会  2012 

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  • 単層カーボンナノチューブナノフィラーの作製とポリビニルアルコールとの複合体への応用

    高分子学会中国四国支部若手研究会  2012 

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  • 前駆体を経由した剛直高分子三次元架橋体の合成

    平成24年度繊維学会秋季研究発表会  2012 

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  • 光電変換色素固定ポリエチレン薄膜の人工網膜への応用と表面電位光応答性に関する研究

    高分子学会中国四国支部若手研究会  2012 

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  • 前駆体を経由した剛直高分子三次元架橋体フィルムの作製

    高分子学会中国四国支部若手研究会  2012 

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  • 電子顕微鏡でみる単層カーボンナノチューブ(SWNT)/高分子複合体繊維およびSWNT単結晶の微細構造とその構造制御

    岡山新材料技術融合フォーラム 招待講演  2012 

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  • 単層カーボンナノチューブの結晶化による固体構造制御およびその微細構造電子顕微鏡観察

    平成23年度繊維学会秋季研究発表会  2011 

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  • 単層カーボンナノチューブの結晶化と固体構造解析

    H23高分子学会年次大会  2011 

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  • 剛直高分子および単層カーボンナノチューブの固体構造の解明と高性能高分子材料への応用

    日本材料学会中国支部材料研究交流会 招待講演  2011 

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  • ポリパラフェニレンテレフタルアミドの単結晶

    H23高分子学会年次大会  2011 

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  • カーボンナノチューブを核材として利用した剛直高分子の結晶化・結晶形態

    H23高分子学会年次大会  2011 

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  • 重合結晶化を利用した芳香族ポリウレアの高次構造形成

    H23高分子学会年次大会  2011 

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  • 重合結晶化により調製したポリ[4-(1,4-フェニレン)オキシフタルイミド]のモルホロジーと共重合がモルホロジーに与える影響

    H23高分子学会年次大会  2011 

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  • ポリパラフェニレンテレフタルアミド単結晶の熱処理による構造安定化

    平成23年度繊維学会年次大会  2011 

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  • 希薄溶液からの結晶化を利用した単層カーボンナノチューブの凝集構造制御

    平成23年度繊維学会年次大会  2011 

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  • 単層カーボンナノチューブ(SWCNT)/高分子複合体およびSWCNT単結晶 ~構造制御と微細構造電子顕微鏡観察~

    関西H&I研究会 第28回研究会 招待講演  2011 

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  • 電子顕微鏡観察による単層カーボンナノチューブ(SWNT)/高分子複合体繊維およびSWNT単結晶の構造制御

    第34回関西繊維科学講座 招待講演  2011 

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  • カーボンナノチューブを核材として利用した剛直高分子の結晶化および結晶形態の制御

    高分子学会中国四国支部若手研究会  2011 

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  • Preparation of Helical Poly(ester-imide) Fibers by Crystallization during Polymerization

    11th Asian Textile Conference  2011 

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  • 剛直高分子三次元架橋体フィルムの作製とその応用

    高分子学会中国四国支部若手研究会  2011 

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  • Preparation of Polybenzimidazole Nanofibers

    11th Asian Textile Conference  2011 

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  • Morphology and Structure of Single-Walled Carbon Nanotube Bundles, Single Crystals and Composite fibers

    11th Asian Textile Conference  2011 

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  • バイオマス材料を用いた磁性ゲル繊維の作製と高機能複合材料への応用

    八雲財団研究発表会  2011 

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  • ナフタレン環を含む自己縮合型ポリイミドの合成と重合相変化を利用した高次構造形成

    H23年度高分子学会高分子討論会  2011 

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  • 化学変換を利用したポリエチレンの再資源化-新規高分子材料の開発

    H23年度高分子学会高分子討論会  2011 

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  • 光電変換色素固定ポリエチレン薄膜の人工網膜への応用と表面電位光応答性に関する研究

    高分子学会中国四国支部若手研究会  2011 

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  • 単層カーボンナノチューブの希薄溶液からの結晶化およびその凝集構造制御

    高分子学会中国四国支部若手研究会  2011 

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  • RtoR(ロール トゥー ロール)方式による球状シリコン太陽電池製造プロセス・装置の開発

    環境学習センターアスエコ平成23年第二回かんきょうひろば全体交流会 招待講演  2011 

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  • Fabrication of High-Performance Nanofibers without Spinning

    6th International Conference on Advanced Fiber/Textile Materials  2011 

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  • カーボンナノチューブを核材として利用した剛直高分子の結晶化および形態制御

    H23年度高分子学会高分子討論会  2011 

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  • 希薄溶液からの結晶化を利用したSWNTの凝集構造制御およびその微細構造電子顕微鏡観察

    H23年度高分子学会高分子討論会  2011 

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  • 重合結晶化を利用したらせん形態ブロックを有するポリエステルイミドの繊維状結晶の調製

    H23年度高分子学会高分子討論会  2011 

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  • カーボンナノチューブを核材として利用した剛直高分子の結晶化および結晶形態の制御

    平成23年度繊維学会秋季研究発表会  2011 

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  • 単層カーボンナノチューブを用いた高性能・高機能高分子複合体の開発

    岡山工学振興会講演会 招待講演  2010 

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  • ポリパラフェニレンテレフタルアミドの希薄溶液からの結晶化

    平成22年度繊維学会年次大会  2010 

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  • ポリベンズイミダゾールナノファイバーネットワークの調製

    H23年度高分子学会討論会  2010 

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  • 単層カーボンナノチューブの結晶化、結晶形態

    H23年度高分子学会討論会  2010 

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  • 希薄溶液から結晶化した単層カーボンナノチューブの結晶形態

    H22高分子学会年次大会  2010 

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  • 希薄溶液から作製したポリパラフェニレンテレフタルアミド単結晶の結晶形態

    H22高分子学会年次大会  2010 

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  • フラロデンドロン/単層カーボンナノチューブ超分子複合体を利用した光水素発生

    高分子学会中国四国支部若手研究会  2010 

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  • 重合結晶化を利用したアラミドパルプの調製と精密重合法への展開

    平成22年度繊維学会年次大会  2010 

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  • ポリパラフェニレンテレフタルアミド単結晶の結晶形態

    H23年度高分子学会討論会  2010 

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  • らせん状ポリエステルイミド繊維の調製

    平成22年度繊維学会年次大会  2010 

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  • ポリパラフェニレンテレフタルアミド単結晶の結晶形態

    高分子学会中国四国支部若手研究会  2010 

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  • 単層カーボンナノチューブ(SWCNT)/高分子複合体およびSWCNT単結晶-構造制御と微細構造電子顕微鏡観察-

    山陽技術振興会交流会 招待講演  2010 

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  • 単層カーボンナノチューブの結晶化と固体構造解析

    高分子学会中国四国支部若手研究会  2010 

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  • 単層カーボンナノチューブを核材とした剛直高分子の結晶化・結晶形態

    高分子学会中国四国支部若手研究会  2010 

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  • 重合結晶化を利用したらせん状ポリエステルイミド結晶の調製

    H22高分子学会年次大会  2010 

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  • 単層カーボンナノチューブを核材とした剛直高分子ポリパラフェニレンベンゾビスチアゾールの結晶化

    H22高分子学会年次大会  2010 

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  • 単層カーボンナノチューブの希薄溶液からの結晶化

    平成22年度繊維学会年次大会  2010 

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  • 単層カーボンナノチューブを核材とした剛直高分子の結晶化・結晶形態

    平成22年度繊維学会年次大会  2010 

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  • 天然多糖類を利用した有機無機複合材料の作製と機能探索

    高分子学会中国四国支部若手研究会  2009 

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  • Poly(1,4-phenylene terephthalamide) (PPTA)の希薄溶液からの結晶化

    高分子学会中国四国支部若手研究会  2009 

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  • オリゴメチレン部位をコアに持つPAMAMデンドリマーを利用した単層カーボンナノチューブ超分子複合体形成

    高分子学会中国四国支部若手研究会  2009 

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  • フラロデンドロン/単層カーボンナノチューブ超分子複合体を利用した水素発生

    高分子学会中国四国支部若手研究会  2009 

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  • 単層カーボンナノチューブ(SWCNT)/高分子複合体およびSWCNT単結晶の作製とその微細構造電子顕微鏡観察

    ミニシンポジウム カーボンナノチューブで切り拓く先端材料化学  2009 

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  • Preparation of Poly(p-phenylene pyromelliteimide) Needle-like Crystal

    The 10th Asian Textile Conference  2009 

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  • Morphology and Structure of Single-walled Carbon Nanotube Bundles, Single Crystals and Composite Fibers

    2009 Japanese-Sino Fiber symposium  2009 

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  • Poly(2,5-benzimidazole) Nanofibers prepared by Reaction-induced Crystyallization

    The 10th Asian Textile Conference  2009 

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  • 重合相変化を利用したポリ(p-フェニレンピロメリットイミド)のモルホロジー制御

    H21高分子討論会  2009 

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  • ポリ[4-(1,4-フェニレン)オキシフタルイミド]の繊維状結晶の調製と共重合が形態に及ぼす影響

    H21高分子討論会  2009 

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  • リサイクル発砲ポリスチレンを用いた自動車用クッション部材の軽量化

    第7回発泡スチロール再資源化協会技術発表会  2009 

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  • Poly(1,4-phenylene terephthalamide) (PPTA)単結晶の作製

    平成21年度繊維学会年次大会  2009 

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  • 希薄溶液から結晶化した単層カーボンナノチューブ

    平成21年度繊維学会年次大会  2009 

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  • Dispersion of Single-Walled Carbon Nanotubes Using Poly(amidoamine) Dendrimer Having Alkyl Chain at the Core

    第37回フラーレン・ナノチューブ総合シンポジウム  2009 

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  • 繊維状ポリ(p-フェニレンピロメリットイミド)の調製

    平成21年度繊維学会年次大会  2009 

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  • 重合誘起型オリゴマー相分離を利用した[4-(1,4-フェニレン)オキシフタルイミド]の高次構造制御

    第23回中国四国地区高分子若手研究会  2008 

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  • 剛直高分子ポリパラフェニレンベンゾビスチアゾールフィブリル状結晶の熱処理による構造再形成

    第57回高分子学会年次大会  2008 

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  • Fabrication of nanoribbon of high-performance polyamide

    ACS National meeting  2008 

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  • 重合相変化を利用したポリ[2,6-(1,4-フェニレン)-ジイミダゾベンゼンのモルフォロジー制御

    第39回繊維学会夏季セミナー  2008 

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  • リサイクル発泡ポリスチレンを用いた自動車用クッション部材の軽量化

    第6回発泡スチロール再資源化協会技術発表会  2008 

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  • 重合結晶化を利用した芳香族ポリイミド材料の開発

    第57回高分子討論会  2008 

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  • 重合誘起型オリゴマー結晶化を利用した芳香族ポリアミドの調製と連鎖的重合様式への変換

    第57回高分子討論会  2008 

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  • 重合結晶化を利用したポリ(p-フェニレンピロメリットイミド)の結晶性微粒子の調製とその結晶構造解析

    第23回中国四国地区高分子若手研究会  2008 

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  • アルキル鎖をコアに持つポリアミドアミンデンドリマーを用いた単層カーボンナノチューブの可分散化

    第57回高分子討論会  2008 

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  • 二重自己組織化重合を利用した共重合ポリエステルのモルホロジー制御

    高分子討論会  2007 

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  • 分子鎖長を揃えた剛直高分子ポリパラフェニレンベンゾビスチアゾールの急冷結晶化物の溶液熱処理による構造再形成

    第22回中国四国地区高分子若手研究会  2007 

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  • 剛直性ポリイミドの高次構造制御―繊維状結晶の調製

    高分子討論会  2007 

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  • 分子鎖長を揃えた剛直高分子ポリパラフェニレンベンゾビスチアゾールのフィブリル状結晶の熱処理による構造再形成

    H19繊維学会秋季研究発表会  2007 

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  • 非等モル環境下でのポリイミドの合成

    高分子討論会  2007 

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  • 繊維状ポリ(4-フタルイミド)結晶の調製

    高分子学会年次大会  2007 

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  • 単層カーボンナノチューブ/高分子複合体繊維の微細構造電子顕微鏡観察

    高分子学会中国四国地区高分子研究会  2007 

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  • 重合相変化を利用したポリベンズイミダゾールの高次構造形成

    高分子学会年次大会  2007 

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  • 芳香族ポリエステルの二重自己組織化重縮合

    高分子学会年次大会  2007 

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  • ポリ(4-フタルイミド)繊維状結晶の調製

    繊維学会年次大会  2007 

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  • ポリベンズイミダゾールの重合相変化を利用した繊維状集合体の調製

    繊維学会年次大会  2007 

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  • 剛直高分子三次元架橋体/ナイロン6複合体の作製とその力学的性質

    高分子討論会  2007 

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  • 重合結晶化を利用した共重合ポリエステルのモルフォロジー形成

    H19繊維学会秋季研究発表会  2007 

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  • 分子鎖長を揃えた剛直高分子ポリパラフェニレンベンゾビスチアゾール結晶の熱処理による構造再形成

    日本化学会西日本大会  2007 

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  • Atomic Force Microscopic Observation of Trehalose?Treated and Dried Corneal Surface

    Invest. Ophthalmol. Vis. Sci.  2006 

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  • Synthesis of Poly(ethylene-block-vinyl alcohol) for use as Amphiphilic Film Surface at High Temperature.

    16th International Conference on Organic Synthesis  2006 

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  • ポリエチレンフィルム表面の構造と細胞増殖性

    繊維学会年次大会  2006 

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  • 重合誘起オリゴマー結晶化を利用したポリベンズイミダゾールナノファイバーの調製

    高分子学会年次大会  2006 

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  • カーボンナノチューブ/高分子複合体の構造と力学的性質

    高分子学会中国四国支部高分子研究会  2006 

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  • Mixed Neuronal and Glial Colony Formation on the Surface of Photoelectric Dye-Coupled Polyethylene (Okayama University Type Retinal Prosthesis)

    Invest. Ophthalmol. Vis. Sci.  2006 

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  • Fabrication of Poly[2,2’-(p-phenylene)-5,5’-bibenzimidazolke] Nanofibers by Using Reaction-induced Crystallization of Oligomers

    Polychar 14  2006 

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  • 剛直高分子の分子量分別2

    高分子学会年次大会  2006 

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  • カーボンナノチューブ/ポリアクリロニトリル複合体繊維の微細構造電子顕微鏡観察ーカーボンナノチューブの種類と分散性ー

    第16 回繊維連合研究発表会、講演番号1B03 、要旨集p34  2005 

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  • Morphology control of poly(p-mercaptobenzoyl) by modifcation of oligomer end-group.

    229th ACS National Meeting  2005 

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  • カーボンナノチューブ/高分子複合体の微細構造と力学的性質

    第6 回理研シンポジウム「高分子結晶の構造と機能」 講演要旨集, 6 , 9-14  2005 

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  • フラロデンドロン/SWNT超分子複合体形成

    日本化学会第85春季年会、講演予稿集、3F7-29 (2005)  2005 

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  • Morphology of poly(p-oxycinnamoyl) formed by hydrodynamically induced crystallization during solution polymerization.

    229th ACS National Meeting  2005 

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  • カーボンナノチューブ/高分子複合体繊維の構造と力学的性質

    第51 回高分子研究発表会、講演番号 C-20  2005 

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  • フラロデンドロン/単層カーボンナノチューブ(SWNT)超分子複合体形成

    第54 回高分子学会年次大会、Polymer Preprints, Japan, 54(1), 902 (2005)  2005 

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  • Supramolecular Wrapping around Single-Walled Carbon Nanotubes with Fullerodendrons

    The 8th SPSJ International Polymer Conference, Abstracts, p.609 (2005).  2005 

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  • Transmission Electron Microscopy Studies in SingleWall Carbon Nanotube/Polymer composite fbers

    2005 International Conference on Advanced Fibers and Polymer Materials, proceeding p655-659  2005 

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  • オリゴマー相分離を利用した重縮合によるポリアゾメチンエステルの高次構造制御

    高分子討論会、講演番号1U04  2005 

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  • Supramolecular Wrapping around Single-Walled Carbon Nanotubes with Fullerodendrons

    2005 International Chemical Congress of Pacific Basin Societies (PACIFICHEM2005), Abstracts, p.681 (2005).  2005 

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  • 重合結晶化法により調整したPoly(pphenylene pyromelliteimide) 菱形 結晶の構造

    第53 回高分子学会年次大会, 講演番号ⅠPg159  2004 

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  • 単層カーボンナノチューブ/PBO複合体繊維の微細構造電子顕微鏡観察

    平成16 年度繊維学会年次大会、講演番号 2L03  2004 

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  • Polymer/Carbon Nanotube Composite: Challenges and Opportunites

    American Society for Composites, Technical Conference  2004 

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  • 剛直高分子(PBZT,PBZO) 単結晶の成長機構

    平成16 年度繊維学会秋季研究発表会、講演番号 1B07  2004 

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  • POLYMER/CARBON NANO FIBER COMPOSITE FIBERS

    International SAMPE Symposium and Exhibition, 5F5  2004 

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  • POLYMER/CARBON NANOTUBE COMPOSITES:CHALLENGES AND OPPORTUNITIES

    International SAMPE Symposium and Exhibition, 7F1  2004 

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  • ブロック組成を有するポリマーウイスカー の調製

    第53 回高分子学会年次大会, 講演番号ⅠPa049  2004 

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  • 単層カーボンナノチューブ/PAN複合体 繊維の微細構造電子顕微鏡観察

    第53 回高分子学会年次大会, 講演要旨 集, 53(1) 932 講演番号 Ⅰ Pg065  2004 

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  • Preparation of Whisker comprised of p-Oxybenzoyl and p-Mercaptobenzoyl in a Block Manner

    Japan-China-Korea Joint Symposium on Textile  2004 

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  • 剛直高分子3次元架橋体の構造制御

    高分子討論会  2003 

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  • 「Rigid Polymer Crystals」

    韓国高分子学会年次大会(招待講演)  2003 

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  • PBZT結晶の形態・構造の分子量分布依存性

    繊維学会年次大会  2003 

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  • PBZT三次元架橋体の構造制御

    繊維学会年次大会  2003 

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  • Studies on poly(ethylene terethphalate-co-4,4' bibenzoate) fibers.

    55th Southeast Regional Meeting of the American Chemical Society  2003 

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  • Structure, processing, and properties of polymer/SWNT composite fibers.

    55th Southeast Regional Meeting of the American Chemical Society  2003 

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  • 剛直高分子ポリパラフェニレンベンゾビスチアゾールの単結晶の形態と結晶欠陥

    第18回中国四国地区高分子若手研究会  2003 

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  • 剛直高分子の結晶形態と結晶欠陥分子量分布依存性

    高分子討論会  2003 

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  • Crystallization Mechanism of Rigid Polymer from Dilute Solution

    International Symposium on Polymer Crystallization,  2002 

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  • 多孔性剛直高分子3次元架橋体膜の作製

    繊維学会年次大会  2002 

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  • Defects and Chain Disorientation in a Rigid Polymer Crystal

    International Conference on Materials for Advanced Technologies  2001 

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  • 片末端が固定されたポリエチレン結晶化物の形態

    繊維学会 平成13年度秋季研究発表会  2001 

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  • 剛直高分子板状晶の成長機構

    繊維学会 平成13年度秋季研究発表会  2001 

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  • 板状晶表面から突出した剛直高分子鎖末端の走査プローブ顕微鏡による直接観察(依頼講演)

    日本化学会 九州支部・同中国四国支部合同大会  2001 

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  • ポリエチレン/ポリビニルアルコールブロック共重合体の結晶化

    日本化学会九州支部・同中国四国支部合同大会  2000 

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  • ナイロン6/剛直高分子ブロック共重合体の結晶形態

    日本化学会九州支部・同中国四国支部合同大会  2000 

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  • 熱処理による剛直高分子の結晶欠陥構造変化

    日本化学会九州支部・同中国四国支部合同大会  2000 

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  • Preparation and Mechanical Properties of PBZT Network/Nylon6 Molecular Composite

    Polycondensation 2000  2000 

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  • 剛直高分子の分子量分別と結晶形態

    繊維学会年次大会  2000 

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  • 剛直高分子の分子量分別

    繊維学会秋季研究発表会  2000 

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  • Poly(ethylene-block-vinyl alcohol) film with amphiphilic surface at high temperature

    The 10th International Symposium on Fine Chemistry and Functional Polymers,  2000 

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  • スキャニングプローブ顕微鏡による剛直高分子結晶表面構造の解析

    日本化学会九州支部・同中国四国支部合同大会  2000 

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  • ポリエチレンインフレーションフィルムの延伸による構造変化と力学物性

    高分子学会年次大会  1999 

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  • 剛直高分子単結晶のSPM観察

    繊維学会年次大会  1999 

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  • Scanning Probe Microscopy of Polymer Chain Ends Distribution on a Rigid Polymer Crystal

    2nd International Symposium on HITECH Polymers and Polymeric Complexes (HPPC-Ⅱ),  1999 

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  • Super Structure Formation in Wholly Aromatic Copolyester Fiber

    2nd International Symposium on HITECH Polymers and Polymeric Complexes (HPPC-Ⅱ)  1999 

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  • ポリエチレン単結晶の固体構造を利用した両親媒性ブロック共重合体

    高分子学会年次大会  1999 

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  • PBZT/Nylon6ブロック共重合体の結晶化

    高分子学会年次大会  1999 

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Awards

  • 岡山工学振興会 科学技術賞

    2021.7   岡山工学振興会   「剛直高分子三次元架橋体を用いた固体高分子形燃料電池用プロトン伝導膜の作製」

    内田哲也

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  • 繊維学会賞

    2018.6   繊維学会   「希薄溶液からの結晶化を利用した高性能ナノファイバーの創製と複合体への応用」

    内田哲也

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  • ポリマー材料フォーラム 優秀発表賞

    2017  

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    Country:Japan

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  • 平成26年度内山勇三科学技術賞

    2014  

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    Country:Japan

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  • 日本材料学会中国支部学術奨励賞

    2011  

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    Country:Japan

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  • 繊維学会関西繊維科学研究奨励賞

    2011  

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    Country:Japan

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  • 岡山工学振興会科学技術賞

    2011  

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    Country:Japan

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  • 岡山工学振興会科学技術賞

    2005  

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    Country:Japan

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  • 繊維学会論文賞

    2004  

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    Country:Japan

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  • 高分子学会「高分子研究奨励賞」

    2003  

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    Country:Japan

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  • 岡山工学振興会科学技術賞

    2000  

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Research Projects

  • 環-鎖平衡を利用した芳香族高分子材料のケミカルリサイクル技術の開発

    Grant number:18K19877  2018.06 - 2021.03

    日本学術振興会  科学研究費助成事業 挑戦的研究(萌芽)  挑戦的研究(萌芽)

    木村 邦生, 山崎 慎一, 新 史紀, 内田 哲也

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    Grant amount:\4290000 ( Direct expense: \3300000 、 Indirect expense:\990000 )

    芳香族ポリイミド,芳香族ポリアミド,液晶性全芳香族ポリエステル,芳香族ポリエーテルスルホンなどのスーパーエンジニアリングプラスチックは,自動車材料,航空宇宙材料や電気電子材料などに広く使用されている.しかし,プラスチックの使用量が増すにつれ,廃プラスチックによる環境問題が顕在化してきており,スーパーエンプラにおいても廃棄後の再利用や再生が求められる.マテリアルリサイクルとケミカルリサイクルを効率的に組み合わせることで資源としてのリサイクル性を向上できるが,高性能なスーパーエンプラでも使用環境下での分解に伴う性能劣化は避けられず,マテリアルリサイクルには限界がある.よって,ケミカルリサイクルが重要となってくる.しかし,原料モノマーまで分解する従来のケミカルリサイクルでは,工程数の多さと煩雑さから経済的に機能していないのが現状である.そこで,スーパーエンプラの環-鎖平衡を利用して廃スーパーエンプラを環状オリゴマーに変換し,必要に応じて開環重合によりポリマーを再生するという新しい省エネルギー型ケミカルリサイクル技術の開発を目指す.平成30年度は対象を芳香族芳香族ポリエステルとし,環状オリゴマーへの変換効率が高いと考えられるカルド型ジオールと2,5-フランジカルボン酸系ポリエステルを検討した.ポリエステルの重合条件を検討し,構造の異なる5種類のポリエステルを合成することができた.重合過程で生成するオリゴマーをTOF-MASSにて測定したところ,環状エステルの生成は明確には観察されなかった.環-鎖平衡の可能性はあるが,環化しやすいと考えられるカルド型ポリエステルでも重合過程で環状オリゴマーの生成を経由する可能性は低いことが分かった.ポリエステルにおいては,求核性の高い水酸基末端が自己環化反応には有効であると考え,水酸基末端ポリエステルの調製を行っている.

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  • 高強度高弾性率、高耐熱性、高熱伝導性剛直高分子ナノファイバーの高性能材料への応用

    Grant number:18K05237  2018.04 - 2021.03

    日本学術振興会  科学研究費助成事業 基盤研究(C)  基盤研究(C)

    内田 哲也

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    Grant amount:\4420000 ( Direct expense: \3400000 、 Indirect expense:\1020000 )

    希薄溶液からの結晶化を利用して、剛直高分子Poly(p-phenylenebenzobisoxazole) (PBO)のナノファイバーを作製し、形成機構の解明と高性能材料への応用を検討した。剛直高分子PBOは、究極的に優れた性能(高強度、高弾性率、高耐熱性、高熱伝導性、化学安定性、電気絶縁性等)が期待されている。しかしながら分子鎖の剛直性ゆえに融解せず、強酸にしか溶解しないため、PBOナノファイバーの作製は困難であった。そこで希薄溶液からの結晶化を利用してPBOナノファイバーを作製する全く新しい方法を確立し、PBOナノファイバーの構造の特徴と形成機構を明らかにした。得られたPBOナノファイバーを用いて高分子との複合体を作製し、その構造制御と物性評価を行った。検討内容は以下のとおりである。
    ①PBOナノファイバーの結晶性、微結晶配向、微細構造と形成機構の解明:作製条件(PBO分子量、急冷温度、PBO濃度、溶媒種類等)の異なるナノファイバーの構造をX線回折、透過型電子顕微鏡観察等により検討した。結晶化初期の構造を検討した。
    ②PBOナノファイバーシートの高熱伝導性、熱伝導異方性および複合体への応用:PBOナノファイバーで積層シートを作製し、PBOナノファイバーの配向と熱物性を検討した。
    ③PBOナノファイバー/高分子複合体の構造と力学特性、熱伝導性の解明:PBOナノファイバーと高分子の複合体を作製し、構造(NF配向をX線回折で測定)、力学特性、熱伝導性、高熱伝導性フィラー間に充填される高分子成分の熱伝導性向上について検討した。

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  • Development of built-up synthesis of high-performance polymer hollow spheres and their usages

    Grant number:16H04205  2016.04 - 2019.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)  Grant-in-Aid for Scientific Research (B)

    KIMURA KUNIO

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    Grant amount:\15210000 ( Direct expense: \11700000 、 Indirect expense:\3510000 )

    Poly(p-phenylene-5-isophtalamide)(PPHIA) hollow spheres were prepared by the direct polycondensation in aromatic solvent. In order to use these spheres as industrial materials, the methods for size control and porosity control are required. Temperature jump during polymerization and polymerization in poorer solvent were efficient to control the size and it could be changed from 0.7 to 4.3 micrometer by these methods. Further, it was found that the polymerization at 280 degree C at the beginning of the polymerization and then at 320 degree C increased the porosity. Poly(imidazole-amide) did not provide the hollow spheres, even though the microspheres having dimples on the surface were formed.

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  • Preparation of Rigid Polymer Nanofiber by using Crystallization from Dilute Solution and its application to composite films

    Grant number:15K05630  2015.04 - 2018.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)  Grant-in-Aid for Scientific Research (C)

    UCHIDA Tetsuya

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    Grant amount:\5070000 ( Direct expense: \3900000 、 Indirect expense:\1170000 )

    Poly(p-phenylene benzobisoxazole) (PBO) has excellent thermal stability and mechanical properties because of its rod-like rigid structure. Preparing nanofibers of PBO using ordinary methods is difficult (e.g., electrospinning) because PBO is not soluble in organic solvents. Herein, we report the preparation of PBO nanofibers via crystallization from a dilute solution in sulfuric acid. In addition, a PBO nanofiber mat was prepared that exhibited extremely high thermal stability and high thermal diffusivity, etc.

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  • Development of Optical Resolution Polymerization of Polylactide

    Grant number:15K12245  2015.04 - 2017.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research  Grant-in-Aid for Challenging Exploratory Research

    KIMURA Kunio

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    Grant amount:\2600000 ( Direct expense: \2000000 、 Indirect expense:\600000 )

    Poly(L-lactide) (PLLA) is a top runner of biodegradable plastics and the properties iss highly related to the content of unit off D-lactic acid (D-unit) in PLLA. Therefore, the content of D-unit should be strictly controlled. In this study, the new control method of D-unit in PLA was examined by the crystallization during ring-opening cationic polymerization of partial racemic lactide in solution under shearing. The content of D-unit of the precipitated polymer crystals was much lower than the content of D-unit in feed. Further, it was found that the shearing rate influenced on the content of D-unit and higher rate made the content of D-unit lower.

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  • Development of eco-preparation procedure of aramide from wasted PET

    Grant number:25550070  2013.04 - 2015.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research  Grant-in-Aid for Challenging Exploratory Research

    KIMURA Kunio, YAMAZAKI Shinichi, UCHIDA Tetsuya

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    Grant amount:\2860000 ( Direct expense: \2200000 、 Indirect expense:\660000 )

    In order to develop the sustainable society, aramides were prepared by reaction-induced crystallization during ester-amide exchange reaction between PET and aromatic diamines. Further, aromatic polybenzimidazoles were also obtained by the similar procedure between PET and aromatic tetramines. This procedure provides a novel upgrade recycle of PET.

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  • Crystallization control of topological blend polymer which consists of cyclic polymer as a component

    Grant number:24550256  2012.04 - 2015.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)  Grant-in-Aid for Scientific Research (C)

    YAMAZAKI Shinichi, KIMURA Kunio, UCHIDA Tetsuya, OKIHARA Takumi, KOBAYASHI Keiko

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    Grant amount:\5590000 ( Direct expense: \4300000 、 Indirect expense:\1290000 )

    The purpose of this work is to clarify the role of entanglement species on the crystallization of polymers through observation of crystallization of a topological blend polymer which consists of cyclic polymer. Topological blend polymer means the mixing of cyclic and linear polymers. The following issues were investigated. (1) Several kinds of cyclic and linear polyethylene with different molecular weight were prepared. Crystallization at the quiescent state and under the flow were observed by means of polarizing optical microscope. The degree of supercooling, flow rate and strain dependence of the crystallization behavior were made clear. (2) Observation by a scanning electron microscope and crystal structure analysis by wide angle X-ray diffraction measurement were performed for various blends samples.

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  • Preparation of SWNT single crystals by using crystallization from dilute solution and its application to the high-performance material

    Grant number:23550244  2011 - 2013

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)  Grant-in-Aid for Scientific Research (C)

    UCHIDA Tetsuya

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    Grant amount:\5330000 ( Direct expense: \4100000 、 Indirect expense:\1230000 )

    In this study, we crystallized the single-walled carbon nanotube (SWNT) from dilute solution. The crystal growth model of SWNT was proposed by transmission electronmicroscopy (TEM) observation. Electron diffraction spots of SWNT crystals were observed more clearly than that of SWNT bundles. Morphology of SWNT crystal can be controlled by crystallization condition.
    Water-dispersible SWNT have been prepared by ultrasonication in H2SO4/HNO3 mixture. SWNT nanofiller have been prepared by crystallization. Poly (vinyl alcohol) (PVA)/SWNT nanofiller composite films were prepared. Dispersion of SWNT nanofiller in the composite films were observed by transmission electron microscope. Significant improvement in the mechanical property was observed for these composite films.

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  • Preparation of super-engineering plastics from cellulose

    Grant number:23651084  2011 - 2012

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research  Grant-in-Aid for Challenging Exploratory Research

    KIMURA Kunio, YAMAZAKI Shinichi, UCHIDA Tetsuya

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    Grant amount:\2730000 ( Direct expense: \2100000 、 Indirect expense:\630000 )

    Aromatic polyesters and poly(ether-ketone)s were successfully prepared by the polymerization of 2,5-furanedicarboxylic acid which was derived from biomass. They exhibited excellent thermal stability and chemical resistance comparable with conventional super-engineering plastics derived from the monomers synthesized from petroleum. They possess a great potential to replace the super-engineering plastics.

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  • Built-up synthesis of nanofiber networks of high-performance polymers

    Grant number:21350127  2009 - 2011

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)  Grant-in-Aid for Scientific Research (B)

    KIMURA Kunio, YAMAZAKI Shinichi, UCHIDA Tetsuya

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    Grant amount:\12740000 ( Direct expense: \9800000 、 Indirect expense:\2940000 )

    Rigid-rod aromatic polymers are expected to possess many excellent properties. However, many of them do not exhibit processability such as solubility and fusibility because of their rigid-rod structure and they had been given up to use as materials. We examined the reaction-induced phase separation during polymerization in order to overcome the antagonistic problem between the high performance and the less processability. The network structures of polyester, polyimides, polybenzimidazoles and poly(ether ketone) were successfully prepared. And further, helical ribbon of poly(ester-imide) and nanofibers of polyazomethine and polyimidazopyrrolone which is a perfect ladder polymer were also obtained.

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  • 回収ポリエチレンを原料とした易リサイクル性・自己修復性樹脂の開発

    Grant number:21651041  2009 - 2010

    日本学術振興会  科学研究費助成事業 挑戦的萌芽研究  挑戦的萌芽研究

    木村 邦生, 山崎 慎一, 内田 哲也

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    Grant amount:\2200000 ( Direct expense: \2200000 )

    ポリエチレン(PE)に代表される汎用プラスチックは石油を原料としており、石油資源の枯渇化ならびに資源循環型社会構築への対応としてリサイクル性の付与が希求されている。しかし、PEはケミカルリサイクル性を有しておらず、PEを原料とて利用することが困難である。本研究では、回収したPEのリサイクル性の向上を目的として、長鎖PEセグメント化ナイロンの調製を検討した。
    PEをキシレン希薄溶液中、85-70℃で結晶化し単結晶を調製した。調製した単結晶を発煙硝酸処理により、結晶の折りたたみ鎖部位を選択的に酸化切断して末端にカルボキシル基を有するテレケリックPE(PEC)を調製した。カルボキシル基/ニトロ基の比率の最も高い条件で酸化処理を行なった。PECを五塩化リンで処理し末端を酸塩化物で封鎖したテレケリックPE(PECC)を調製した。ヘキサメチレンジアミンとPECCを反応させ、PE由来の長鎖ナイロンを調製した。
    PEの単結晶を調製する際の等温結晶化温度を種々変えることで、厚みの異なる4種類の単結晶を調製し、それらを硝酸酸化させることで、炭素数が56、58、65、ならびに70と分子鎖長の異なるテレケリックPEを得た。PEでは吸水がほとんど認められなかったのに対して、長鎖ナイロンでは、いずれも約1~2%の吸水率であり、アミド結合の特徴が現れた。このことより長鎖ナイロンも親水性であること分かった。次に結晶化の条件を揃えて処理したナイロンの結晶性を評価した。全てのサンプルが結晶性を示し、ポリエチレンの斜方晶に特有な二つのピークと同じ面間隔のピークが見られた。示差走査型熱量計測定では、反応前のPECでは融解時にシングルの吸熱ピークが観察されたが、長鎖ナイロンでは複数の吸熱ピークが観察された。これは二重融解挙動であると考えられる。PEセグメントの鎖長の変化に伴う融点の大きな変化は観察されなかった。以上より、結晶化と選択的硝酸酸化を利用することによって、PEとナイロンの特徴を併せ持った材料を調製することができた。

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  • Biocompatibility of dye-coupled polyethylene film-Application to the retinal prostheses-

    Grant number:19750184  2007 - 2009

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)  Grant-in-Aid for Young Scientists (B)

    UCHIDA Tetsuya

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    Grant amount:\3760000 ( Direct expense: \3400000 、 Indirect expense:\360000 )

    我々はこれまでに、網膜中の視細胞と同等の機能を有する膜の作製を目的とし、光を吸収し電気的信号に変換する光電変換色素をポリエチレンフィルム表面に化学固定する方法を確立している。さらに作製した色素固定フィルムが視細胞未発達のニワトリ受精卵(ヒヨコ)の網膜を刺激し、人工網膜としての機能を有することを明らかにしてきた。人工網膜は眼球の奥に挿入して使用するため、代謝の激しい体内で長期間安定に機能を果たすことが求められる。それに加えて、好ましくない生体反応を起こさず、双極細胞などの神経細胞との親和性に優れ、生体適合性を有することも必須条件である。そこで以下に示す2つの点に着目し、生体内で安定して機能する生体適合性の優れた人工網膜の作製を検討した。
    1)色素固定基板として用いるポリエチレンフィルム表面の物性と生体適合性の検討 2)ポリエチレンフィルム表面の反応性末端基を利用した化学修飾による生体適合性の向上

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  • Safety and efficacy of photoelectric dye-coupled polyethylene films (Okayama University-type retinal prostheses)

    Grant number:18591922  2006 - 2008

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)  Grant-in-Aid for Scientific Research (C)

    MATSUO Toshihiko, UCHIDA Tetuya

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    Grant amount:\3880000 ( Direct expense: \3400000 、 Indirect expense:\480000 )

    光電変換色素をポリエチレン・フィルムに結合した人工網膜(岡山大学方式人工網膜)の試作品は、網膜神経細胞や網膜組織を刺激し、人工網膜として機能することを示してきた。この研究では、人工網膜の機能と安全性について検討した。人工網膜表面に培養した網膜神経細胞は、光刺激に反応して、細胞内カルシウムイオンの上昇をきたすことを明らかにした。また、素材として、ポリエチレン・フィルムの結晶状態を変えると、グリア細胞が付着しにくい人工網膜を作成することが可能になった。安全性としては、人工網膜の素材として使っている光電変換色素は、光照射下でも網膜神経細胞や網膜色素上皮細胞に対して毒性がないことを証明した。また、人工網膜をラット眼球の網膜下へ埋め込む手術方法を開発し、その組織反応を調べた。その結果、グリアの増殖反応はみられるが、網膜神経細胞に対しては悪影響を及ぼさないことが判明した。網膜色素変性症のモデルラット(RCSラット)の眼球内の網膜下に人工網膜を埋め込むと、失明状態から視覚を回復させることを、ラットの行動実験から明らかにした。

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  • Immobilization of Photoelectric Dye on the Polyethylene Film Surface -A Prototype Retinal Prosthesis-

    Grant number:17560605  2005 - 2006

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)  Grant-in-Aid for Scientific Research (C)

    UCHIDA Tetsuya, SHIMAMURA Kaoru, MATSUO Toshihiko

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    Grant amount:\3600000 ( Direct expense: \3600000 )

    Polyethylene (PE) film was treated with fuming nitric acid at 80°C for 20 min, resulting in introduction of COOH moieties on the film surface. The COOH's were reacted with ethylenediamine, whose amino groups were used for linking with (2-[4-(dibutylamino)phenyl]ethenyl)-3-carboxy-methylbenzo-thiazolium, photoelectric dye (NK-5962), which absorbs visible light and converts the photon energy to electric potentials. The dye molecules were immobilized on the PE film surface and they were able to stimulate chick retinal tissues on incidence of visible light. These facts hopefully lead to development of an artificial retinal prosthesis.

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  • Fractionation and crystallization of wholly aromatic rigid polymer

    Grant number:16550177  2004 - 2005

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)  Grant-in-Aid for Scientific Research (C)

    SHIMAMURA Kaoru, UCHIDA Tetsuya, KIMURA Kunio

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    Grant amount:\3200000 ( Direct expense: \3200000 )

    Fractionation of the rigid polymer, poly(p-phenylene benzobisthiazole) (PBZT) was carried out in dilute solution in conc. methane sulfuric acid using silica gels as packing material of a column. Several combinations of the average chain length of the fractionating materials and the average pore diameter of the gels were examined to improve fractionation resolution. The gels with the average pore diameter near to the average chain length resulted in high fractionation resolution. Single crystals of the fractionated and unfractionated PBZT's were observed by TEM. Both single crystals were fundamentally composed of rod crystals with the chain orienting normal to the rods. The unfractionated PBZT made a cluster of parallel rod crystals, where longer chains penetrated a few rod crystals leaving their chain ends within the crystalline core. On the contrary, with the fractionated polymer, extended- chain rod-like crystals were dispersed isolated from each other. This morphology enables us to estimate the chain length visibly by TEM, for which a few milligrams of the material is enough for the observation.

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  • 導電性プラスチック製アプリケータを用いた癌温熱治療装置の開発と性能評価

    Grant number:13877141  2001 - 2002

    日本学術振興会  科学研究費助成事業 萌芽研究  萌芽研究

    黒田 昌宏, 内田 哲也, 島村 薫, 加藤 博和, 平木 祥夫

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    Grant amount:\1300000 ( Direct expense: \1300000 )

    1)アプリケータの素材として、導電性プラスチックであるポリピロールやポリアニリンの特性を検討した。これらの導電性プラスチックには導電率の程度が低めで経時的に導電率が低下してゆく欠点が見つかった。MRI画像に影響を与えないこと、放射線透過性が高いという性能がアプリケータ素材として要求されるため、導電率が高く、経時的な劣化がない導電性プラスチック素材であるカーボンファイバーを用いて、以降の実験を行った。
    2)アプリケータとしての能力の検討:高周波発信装置、今回新開発した三次元温度分布表示が可能な固形ファントムを用いて、カーボンファイバー製アプリケータの加温特性を、従来の金属製アプリケータの加温特性と比較した。カーボンファイバー製アプリケータの加温能力と加温範囲は従来の金属製アプリケータと同等であった。
    3)放射線透過性の検討:放射線治療用高エネルギーX線および診断用X線に対して、カーボンファイバーの放射線透過性は高く、カーボンファイバーによる放射線透過性の優位な減衰はなかった。
    4)MRI撮像に対する影響の検討:従来の金属製アプリケータと比較して、カーボンファイバーを用いたアプリケータではMRI画像の乱れは低下した。しかし、カーボンファイバーを平面状に成形したアプリケータでは、誘導電流によると思われるわずかなMRI画像の乱れが生じた。このためカーボンファイバーを特殊な形状に成形して改良して検討したところ、画像の乱れを消失できた。
    5)特殊形状カーボンファイバー製アプリケータの加温能力の検討:特殊形状カーボンファイバー製アプリケータの加温能力は、10センチ径までのアプリケータでは従来の金属製アプリケータの加温特性と同等であったが、アプリケータが大きくなると加温分布は不均一になる。
    6)結論:現状では、表在性の比較的小さな腫瘍に対して、今回開発した新型アプリケータは臨床応用可能である。

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  • Rigid Polymer Network with Nano pores and its Application for High Performance Materials

    Grant number:13650748  2001 - 2002

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)  Grant-in-Aid for Scientific Research (C)

    SHIMAMURA Kaoru, MURAKAMI Syozo, UCHIDA Tetsuya, KIMURA Kunio

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    Grant amount:\4000000 ( Direct expense: \4000000 )

    Rigid polymer networks were prepared by polycondensation of 2, 5-diamino-1, 4-benzene-dithiol with a mixture of terephthalic acid (TPA) and trimesic acid (TMA). The apparent density was dependent on TPA/TMA ratio and much less than that of linear PBZT (1.57 g/cm^3), showing existence of many nano voids within the network. As the segment was so rigid, many COOH's were left around the voids. The network swelled twice in weight with ε-caprolactam, which was polymerized into a composite form of nylon6 impregnated rigid polymer network. Extraction of free nylon6 from the composite with formic acid showed that a quarter of nylon6 grafted directly to rigid polymer network. The grafted nylon6 could not crystallize evidenced by DSC measurements. On the other hand, particles of PBZT network (several hundred nm in diameter) were prepared by stopping the polycondensation just before gelation. A composite film was prepared with the particles swollen with ε-caprolactam. The ratio of PBZT network/nylon6 was 1/3 and the apparent density of the composite film was 1.23 g/cm^3 which is higher than that of a pure nylon6 film (1.16 g/cm^3). Significant improvement in the mechanical property was observed for this composite.

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  • 板状晶表面から突出した剛直高分子鎖末端の走査プローブ顕微鏡による直接観察

    Grant number:12750801  2000 - 2001

    日本学術振興会  科学研究費助成事業 奨励研究(A)  奨励研究(A)

    内田 哲也

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    Grant amount:\2400000 ( Direct expense: \2400000 )

    1.剛直高分子板状結晶の成長機構
    剛直高分子板状晶の走査プローブ顕微鏡による表面観察により,比較的長い分子鎖により形成された一次核を起点としてフィブリルが成長し,続いての結晶化によりフィブリル間が埋められ菱形の外形となることがわかった。実際,結晶化途中の試料をろ過し,成長途中を観察するとフィブリル間に孔が観察された。
    2.剛直性分子鎖末端の直接観察
    剛直高分子板状晶を通常の方法でSPM観察しても,表面形態は径約30〜50nmの凹凸が観察されるのみであり,分子鎖一本の姿はどこにも観察されない。そこで本研究では一本の分子鎖末端に探針が接触して生じたカンチレバーの変位を電圧値として検出することにより分子鎖末端の直接観察を行った。カンチレバー先端にレーザー光を照射し,カンチレバーの変位にともなう反射光の変化を光検出器で検知,電圧変換した後,電圧値として検出した。カンチレバーと分子鎖末端の接触により生じるカンチレバーの変位は微小であるため,水の吸着層が試料表面に存在すると分子鎖末端をとらえにくくなる。そこで乾燥窒素雰囲気下で観察できる装置を作製した。更に,使用するプローブと走査速度などの条件を最適化することにより,再現性のある安定した像が得られるようになった。
    3.板状晶表面から突出した剛直高分子鎖末端の空間分布
    同一視野を試料表面とカンチレバーの距離を段階的に変化させて走査し,数十の像を撮影した。これらの像から板状晶表面から突出した分子鎖末端の空間分布をとらえることができ、板状晶表面には長さ数nm以上の孤立した分子鎖末端が存在することがわかった。
    4.分子鎖末端の分子運動
    分子鎖末端と探針の接触により生じた像を詳細に検討した結果、板状晶表面から孤立して突出した分子鎖末端の運動性は室温では小さいことがわかった。

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  • foldできない高分子鎖の結晶化・結晶欠陥

    Grant number:08455457  1996 - 1997

    日本学術振興会  科学研究費助成事業 基盤研究(B)  基盤研究(B)

    島村 薫, 内田 哲也, 山下 祐彦, 沖原 巧

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    Grant amount:\7400000 ( Direct expense: \7400000 )

    1.剛直高分子の分子量分別
    剛直高分子の結晶化では、結晶から突出した配向ciliaを利用した結晶成長が進むため分子量分布が結晶形態に大きな影響を及ぼす。そのため、まず剛直高分子の分子量分別法を開発した。約40nmより短い分子鎖長領域においてPBZT、PBZOの分別に成功した。
    2.分子量分布と結晶形態
    分子量分別した試料では分子鎖長が揃えられているため、ciliaを利用した結晶化は起こらず結果的には板状晶となった。未分別試料では長いciliaを利用して多層板状晶、あるいは多数の棒状晶が並列した形態を示した。
    3.剛直高分子結晶の表面観察
    剛直高分子が板面に対して垂直に配向した板状晶の表面観察を原子間力顕微鏡(AFM)を用いて行った。AFMによる表面観察の結果から、長い分子鎖により形成された一次核を起点として枝状晶が成長し、続いての結晶化により枝状晶間が埋められ菱形の外形となることがわかった。
    4.構造異性の結晶化・結晶欠陥に与える影響
    従来合成できなかったcis-PBZTを合成し、構造異性体であるtrans-PBZTの固体構造と比較することにより、構造異性が結晶化、結晶欠陥に与える影響を検討した。分子鎖に規則的な湾曲が存在するcis-PBZTでは、分子鎖が分子鎖軸方向に沿って互いにずれた結晶欠陥(axial shift)が減少した。
    5.化学構造の結晶化・結晶欠陥に与える影響
    化学構造の異なるcis-PBZOの合成、結晶化を行い、化学構造の結晶化・結晶欠陥に与える影響を検討した。

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    PRTIMES  https://prtimes.jp/main/html/rd/p/000000186.000072793.html  2021.7

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