| Co-Investigator(Kenkyū-buntansha) |
YONEDA Katsumi Nippon Laser&Electronics Lab., Director, 主任研究員
MIZUKAMI Masashi Tohoku University・Institute for Chemical Reaction Science, Post Doctor Fellow, 反応化学研究所, 講師(研究機関研究員)
HARASZTI Tamas Tohoku University・Institute for Chemical Reaction Science, Research Associate, 反応化学研究所, 助手 (40312681)
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| Research Abstract |
The orientation and structuring of thin liquid(of liquid crystal)films confined between two solid surfaces becomes more pronounced than that of bulk liquids. Therefore liquids show different properties in the nanospace from those in the bulk. Their orientation is affected by interactions between solid surfaces and liquid molecules or between liquid molecules, but the detail mechanisms are not well-understood. Under this research program, we developed novel methods for characterizing thin liquid films confined between two solid surfaces of at the solid-liquid interfaces.
The system simultaneously determines the shear and surface as a function of the suface separation was developed. The resonance method was used for the shear measurement. By using this method, we studied the behaviors of variously oriented liquid crystals.
Multiple beam interferometry, the fringes of equal chromatic order(FECO), was used to investigate the absorption properties of aqueous dye(Rhodamine B)films confined between mica surfaces. A new normalization method for the data analysis, using the transmitted intensities of both odd and even order FECO, was developed to obtain the thickness dependence of the absorption of the film. We found that the Rhodamine B molecules were trapped between the mica surfaces below 15 nm separation distance, and only water was expelled out upon compression from the confined space.
The surface forces measurement is a powerful tool to detect structural changes at the solid-liquid interface. Recently, we have found novel cluster formation of alcohol(methanol, ethanol, propanol)adsorbed on silica surface in cyclohexane. FTIR-ATR spectra indicated that the cluster formation involved hydrogen-bonding interactions between surface silanol groups and ethanol hydroxyl groups in addition to those between ethanol hydroxyl groups.
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