一种基于自组装共价单层成膜方式的新型铁电液晶光控取向膜

A Novel Photoalignment Film for Ferroelectric Liquid Crystal Based on Self-Assembled Monolayer Method

提出了一种基于自组装技术的新型光敏材料作为FLC的取向层的新方案,它为在分子尺寸上研究和控制FLC与固态基板之间的相互作用提供了新的途径。光敏材料是通过共价键作用与基板相连接的。线性偏振紫外光的辐照后,即得到了光学各向异性的自组装膜;以该膜作为取向膜能够很好地取向FLC,且所制备的器件的静态对比度可以达到350。其效果已经可以与传统的摩擦聚酰亚胺类薄膜相媲美。

A novel strategy based on self-assembly technology was provided for design of photosensitive material as ferroelectric liquid crystal alignment layer. This development offered new tools for the study and control at molecular level of the interaction of ferroelectric liquid crystal with solid surfaces. The photoreactive material was self-assembled to the substrate by covalent bond linkage due to special chemical adsorption reaction. Through ester bond linkage, cyano group with strong polarity was introduced to be terminus of the film. Under irradiation of linearly polarized ultraviolet light, an optical anisotropic self-assembled film was easily obtained. The irradiated film was demonstrated to result in homogenous alignment of ferroelectric liquid crystal by optical transmittance plot and polarizing microscopy images of ferroelectric liquid crystal cell with different rotation angles. The alignment quality of ferroelectric liquid crystal on this self-assembled monolayer film is comparable to that of commercial rubbed polyimide film with a CR （contrast ratio） of 350.