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

在这个研究项目中，我的目标是创造新的光反应性聚合物液晶，它可以产生高阶的光诱导重定向。例如，在用4-甲氧基肉桂酰氧基联苯取代的新型聚甲基丙烯酸酯液晶（PLC）薄膜中，首次观察到介晶基平面内取向的逆转。通过线偏振紫外线（LPUV）光照射和随后的退火产生逆转。由于侧基的轴向选择性光反应，LPUV光照射引起薄膜的负光学各向异性。热增强取向的方向与光反应的程度和光产物的分布有关，两个方向的诱导取向顺序S均大于0.5。此外，还可以实现三维定向，所制备的薄膜对lcd双折射薄膜具有良好的适用性。

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.