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

Sum frequency generation (SFG) vibrational spectroscopy was employed to investigate the surface structures of polyelectrolyte multilayers (PEMs) constructed by sequentially alternating adsorption of poly(diallyldimethylammonium chloride) (PDDA) and poly(styrenesulfonate) (PSS). It was found that the surface structures and surface charge density of the as-deposited PEMs of PDDA/PSS significantly depend on the concentration of sodium chloride (NaCl) present in the polyelectrolyte solutions. Furthermore, it was found that the surface structure of the as-deposited PEMs is in a metastable state and will reach the equilibrium state by diffusion of the polyelectrolyte chain after an aging process, resulting in a polyelectrolyte mixture on the PEM surfaces.

DOI： 10.1021/acs.langmuir.5b04765

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

添付ファイル： 2015_J Phys Chem B_Qiao.pdf

DOI： 10.1021/acs.jpcb.5b08985

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

Polyrotaxanes, such as supramolecular assemblies with methylated alpha-cyclodextrins (alpha-CDs) as host molecules noncovalently threaded on the linear polymer backbone, are promising materials for biomedical applications because they allow adsorbed proteins possessing a high surface flexibility as well as control of the cellular morphology and adhesion. To provide a general design principle for biomedical materials, we examined the surface reorganization behaviors and adsorption conformations of fibrinogen on the polyrotaxane surfaces with comparison to several random copolymers by sum frequency generation (SFG) vibrational spectroscopy. We showed that the polyrotaxane (OMe-PRX-PMB) with methylated alpha-CDs as the host molecule exhibited unique surface structures in an aqueous environment. The hydrophobic interaction between the methoxy groups of the methylated alpha-CD molecules and methyl groups of the n-butyl methacrylate (BMA) side chains may dominate the surface restructuring behavior of the OMe-PRX-PMB. The orientation analysis revealed that the orientation of the fibrinogen adsorbed on the OMe-PRX-PMB surface is close to a single distribution, which is different from the adsorption behaviors of fibrinogen on other polyrotaxane or random copolymer surfaces.

DOI： 10.1021/acsami.5b07760

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Polyrotaxanes, such as supramolecular assemblies with methylated α-cyclodextrins (α-CDs) as host molecules noncovalently threaded on the linear polymer backbone, are promising materials for biomedical applications because they allow adsorbed proteins possessing a high surface flexibility as well as control of the cellular morphology and adhesion. To provide a general design principle for biomedical materials, we examined the surface reorganization behaviors and adsorption conformations of fibrinogen on the polyrotaxane surfaces with comparison to several random copolymers by sum frequency generation (SFG) vibrational spectroscopy. We showed that the polyrotaxane (OMe-PRX-PMB) with methylated α-CDs as the host molecule exhibited unique surface structures in an aqueous environment. The hydrophobic interaction between the methoxy groups of the methylated α-CD molecules and methyl groups of the n-butyl methacrylate (BMA) side chains may dominate the surface restructuring behavior of the OMe-PRX-PMB. The orientation analysis revealed that the orientation of the fibrinogen adsorbed on the OMe-PRX-PMB surface is close to a single distribution, which is different from the adsorption be

DOI： 10.1021/acsami.5b07760

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

Broadband phase-sensitive vibrational sum frequency generation (SFG) spectroscopy was utilized to study the molecular orientation of molecules adsorbed on dielectric solid substrates. A gold thin film was employed to generate a SFG signal as a local oscillator (LO). To simplify the phase measurement, a self-assembled monolayer (SAM) of octadecyltrichlorosilane (OTS) was used as a standard sample for phase correction of the phase-sensitive SFG measurements on the solid/air interface. It was demonstrated that the absolute orientation of molecules in the LB films on a fused quartz surface can be clearly distinguished by phase-sensitive SFG measurement. In addition, the observation on the SAM of d(35)-OTS reveals that the two C-H stretching modes for alpha-CH2 group are in opposite phase. Furthermore, by using the present phase-sensitive SFG setup, the orientation flipping of water molecules on positively and negatively charged solid/liquid interface can be distinguished.

DOI： 10.1039/c5cp02702k

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-V C H VERLAG GMBH  

Sum frequency generation (SFG) vibrational spectroscopy, an interface-specific technique in contrast to, for example, attenuated total reflectance spectroscopy, which is only interface sensitive, has been employed to investigate the surface and interface structure of soft matter on a molecular scale. The experimental arrangement required to carry out SFG spectroscopy, with particular reference to soft matter, and the analytical methods developed to interpret the spectra are described. The elucidation of the interfacial structure of soft matter systems is an essential prerequisite in order to understand and eventually control the surface properties of these important functional materials.

DOI： 10.1002/tcr.201402039

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

In the present study, stability and structure of single and binary mixed monolayers of an unsaturated phospholipid, DOPC, and a saturated phospholipid, DPPC-d75, on the water surface, were explored using the π-A isotherm, atomic force microscopy (AFM) and sum frequency generation (SFG) vibrational spectroscopy in various environments. Our results demonstrated that DOPC in the monolayers becomes unstable after the exposure to a low concentration of ozone (20 ± 10 ppb) or even to ambient laboratory air, which has a similar ozone level, but is stable in nitrogen or oxygen. DOPC can be selectively oxidized by a trace amount of ozone in the ambient environment but can be partially inhibited by the presence of DPPC in the monolayer. The present study provides useful information for understanding the physicochemical properties of the cell membranes. © 2013 the Owner Societies.

添付ファイル： 2013 - Physical Chemistry Chemical Physics - Structure and stability studies of mixed monolayers of saturated and unsaturated phospholipids under low-.pdf

DOI： 10.1039/c3cp52484a

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記述言語：英語   出版者・発行元：(一社)日本医用マススペクトル学会  

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