Application of Infrared ATR Spectroscopy to Liquid Crystals. III |
| |
Authors: | Kazuaki Wagatsuma Aritada Hatta Wataru Suëtaka |
| |
Institution: | Laboratory of Interface Science of Metals, Faculty of Engineering, Tohoku University , Aramaki Aoba, Sendai, 980, Japan |
| |
Abstract: | Infrared absorption measurements of nematic N-(p-ethoxybenzylidene)-p'-cyanoaniline (EBCA) under a DC electric field were performed by means of our previously reported ATR method. DC voltages up to 15V were applied to the nematic liquid crystal 15 μm thick between a silicon ATR prism (probing electrode) and an In2O3-coated glass electrode (opposite electrode). By using this method the orientational behavior of molecules in boundary layers about 1 μm thick at the Si electrode was investigated. The threshold voltage for the dielectric orientation varied from 2 to 6 V depending upon the boundary conditions at the opposite electrode, and the maximum degree of order of homeotropic orientation was found to be 0.6–0.7. A storage effect, in which a homeotropic texture induced by the electric field remains unaltered even if the field is removed or reversed, was observed. |
| |
Keywords: | liquid crystals x-ray diffraction polymers polysiloxanes |
|
|