偶氮苯侧链液晶聚合物膜快速不饱和光致取向研究

用薄膜透射率变化研究了偶氮液晶聚合物膜不同功率光照条件下的取向速度及取向稳定性，并用锥光干涉图确定了相应介晶基元的取向方向。实验结果表明介晶基元的取向速度和取向度随光照时间和光照功率增加而增加，超过一定功率阈值时，取向变得不稳定，光照时间增加而薄膜的取向度（透射率）反而降低。介晶基元的取向方向结果表明在阈值功率以上强度光照时，介晶基元发生了面内和面外两种取向。面外取向的介晶基元不稳定，在停止光照后容易发生解取向，聚合物膜的透射率降低。而面内取向的介晶基元则能稳定维持其取向状态，不会发生解取向。采用不饱和取向的方法可缩短取向时间95％，薄膜取向度提高1．3倍。4ms的一次曝光足以使聚合物膜产生可读出、稳定的面内取向，取向的结果能保持2年不发生变化。

Fast Unsaturated Orientation of Azobenzene Containing Side-chain Liquid Crystalline Polymer

Orientation of azobenzene containing side-chain liquid crystalline polymer was studied by the transmission measurements and polarized optical microscopy （POM） observation. The results suggest that a higher power energy linearly polarized light irradiation induced an out-of-plain orientation, which showed an increase of transmission and then a decrease of the obtained transmission value. Out-of-plane orientation decreased the stability of the oriented film. Stable orientation was obtained upon a lower power density light beam irradiation. Unsaturated orientation cut down by 95% of radiation time compared those used for the saturated orientation, and it also increased the film orientation order by 1.3 times. Four mi- croseconds expose on the film generated stable orientation. This orientational image can be stably reserved for at-least two years.