High performance photomanipulation in photo-cross-linkable polymer liquid crystals

在这个研究项目中，我的目标是创造出能够产生高阶光致重定向的新型光反应聚合物液晶。例如，首次观察到由4-甲氧基肉桂氧基联苯侧基取代的新型聚甲基丙烯酸酯液晶(PLC)薄膜中介晶基团的面内重定向方向发生逆转。反转是由线偏振紫外光(LPUV)照射和随后的退火热处理产生的。由于侧基的轴向选择性光反应，LPUV光照射导致薄膜的负光学各向异性。热增强重定向的方向取决于光反应的程度和光产物的分布，而诱导取向级数S大于0.5。此外，可以实现三维重取向，所得的薄膜对LCD的双折射薄膜具有很好的适用性。

In this research project, I aimed to create new photoreactive polymer liquid crystals which generate high order of photoinduced reorientation. For example, reversion of the in-plane reorientation direction of mesogenic groups has been observed for the first time in novel polymethacrylate liquid crystal (PLC) films substituted with a 4-methoxycinnamoyloxybiphenyl side group. The reversion was generated by irradiation with linearly polarized ultraviolet (LPUV) light and a subsequent annealing. Irradiation with LPUV light induces negative optical anisotropy of the films as a result of an axis-selective photoreaction of the side groups. The direction of the thermally enhanced reorientation is dependent on the degree of photoreaction and the distribution of photoproducts, while the induced orientational order in both directions, S, was larger than 0.5. Additionally, three-dimensional reorientation cane be realized and the resultant film showed good applicability to birefringent film for LCDs.