Effect of photoisomerization of azobenzene dopants on the flexoelectric properties of short-pitch cholesteric liquid crystals

被引：0

作者：

Komitov, Lachezar ^{[1
]}

Ruslim, Christian ^{[2
]}

Ichimura, Kunihiro ^{[2
]}

机构：

[1] Department of Microelectronics and Nanoscience, Chalmers University of Technology, Göteborg University, Göteborg,S-41296, Sweden

[2] Research Laboratory of Resources Utilization, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama,226-8503, Japan

来源：

Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | 2000年 / 61卷 / 05期

关键词：

Cholesterics - Flexoelectric - Flexoelectric coefficients - Flexoelectro-optics - Liquid crystal materials - Molecular shapes - Uniform lying helix - UV illuminations;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

The flexoelectric properties of short-pitch cholesteric mixtures doped with three different azobenzenes, 4,4′-dihexyloxyazobenzene (4,4′-azo), 3,38 -dihexyloxy-2,2′-dimethylazobenzene (3,3′-azol), and 3,3′- dihexanoyloxy-2,2′-dimethylazobenzene (3,3′-azo2), respectively, were studied upon illumination with uv light. Their effective flexoelectric coefficients were derived from the flexoelectro-optic response of the mixtures aligned in uniform lying helix texture. Considering the fact that the pitch of the mixtures became shorter upon uv illumination, an increase of their effective flexoelectric coefficients was found to take place due to the photoisomerization of the dyes. The largest change was found for the coefficient of the guest-host mixture containing 4,4′-azo dye, most probably due to the bent shape of the dye cis-isomer. This observation is in good agreement with our previous studies on the influence of the molecular shape on the liquid-crystal flexoelectric properties and it suggests a possible way for enhancement of the amplitude of flexoelectro-optic response in cholesterics by using liquid-crystal materials with pronounced molecular shape dissymmetry. ©2000 The American Physical Society.

引用

页码：5379 / 5384