Application of Infrared ATR Spectroscopy to Liquid Crystals. II. Surface-induced Orientation of Nematic MBBA and Reorientation in Electric Fields

Autor: Hatta, Aritada, Nohara, Hideaki, Suëtaka, Wataru
Zdroj: Bulletin of the Chemical Society of Japan; April 1978, Vol. 51 Issue: 4 p967-973, 7p
Abstrakt: A polarized infrared ATR technique was used to demonstrate the orientation of a nematic liquid crystal, N-(p-methoxybenzylidene)-p-butylaniline (MBBA), due to the walls of the electrode and an externally applied DC electric field. Polarized ATR spectra were obtained as a function of the field strength on liquid films 15 (μm thick between a silicon ATR prism and a brass plate serving as electrodes. The observed infrared dichroism revealed the average orientation of molecules in boundary layers about 1 μm thick on the Si electrode surface. The ordering or packing of molecules before application of the field affects the response of molecules to the electric field in a striking manner. Molecular orientations on the Si electrode are discussed in some detail.
Databáze: Supplemental Index