摘要
选用侧链含有双元光敏基团的梯形聚硅氧烷材料作为光取向材料,采用偏光显微镜(POM)及晶体旋转法,研究了梯形聚硅氧烷光取向层的制备条件,包括取向剂浓度、紫外光辐照度及光照时间对光取向层的取向行为的影响.结果表明,取向剂浓度越大,光敏基团更易于组装成垂直取向状态,进而诱导液晶分子形成垂直取向的分子排列方式.在一定的紫外光辐照度范围内可以有效地引起偶氮苯光敏基团的面内、面外异构化及再取向,有利于取向层诱导液晶分子形成平面取向的分子排列方式.紫外光光照时间的增加有利于取向层诱导液晶分子形成平面取向的分子排列方式.
Photo-alignment materials were prepared from ladder-like polysiloxane materials containing dual photo-reactive groups. The effects of solution concentration, irradiance and irradiation time on the photo-alignment behavior of the ladder-like polysiloxane film were investigated by polarized optical microscopy （POM） and the crystal rotation method. It was found that photo-reactive groups were prone to form homeotropic alignment with the increase of the solution concentration, and then it could induce liquid crystal molecules to form homeotropic alignment. The isomerization and reorientation both in and out of plane of azobenzene groups could be achieved within a suitable irradiance range, and then it was beneficial to the formation of in-plane alignment of liquid crystal molecules. Increasing the irradiation time availed the formation of in-plane alignment of liquid crystals molecules.
出处
《北京科技大学学报》
EI
CAS
CSCD
北大核心
2008年第7期786-790,共5页
Journal of University of Science and Technology Beijing
基金
教育部重点资助项目(No.104187)
北京市科委科技计划资助项目(No.Y0405004040121)
高等学校博士点基金资助项目(No.20050008036)
关键词
梯形聚硅氧烷
光取向
平面取向
垂直取向
光敏基团
ladder-like polysiloxane
photo-alignment
in-plane alignment
homeotropic alignment
photo-reactive group
