光折变聚合物PVK∶5CB∶C_(60)中生色团动态取向的研究

考虑到聚合物基体对生色团的取向的阻尼作用 ,以及外电场对生色团的极化作用 ,在已有的生色团气体取向模型基础上 ,建立了非气体取向模型 .并利用数值计算方法求解了这一非气体取向模型方程 .讨论了外加电场、温度对生色团取向的动态过程和稳态分布的影响 ,比较了两模型的计算结果 .采用椭圆偏振法 ,测量了光折变聚合物PVK∶5CB∶C60 中的生色团 5CB在聚合物基体PVK中动态取向过程 .给出了生色团的稳态和动态取向参量随外加电场和温度的变化关系 .理论与实验的比较 ,进一步证明了非气体取向模型的合理性

Study of chromophore orientation dynamics in photorefractive polymer PVK∶5CB∶C60

Based on the gas model, a non gas model for the reorientation of chromophores in photorefractive polymers was established by considering the effect of polymer on the reorientation of chromophores and the effect of applied electric field on the chromophores. A numerical method was used to solve the model equation. The influences of the applied electric field and temperature on the dynamic and steady state reorientation of chromophores were discussed according to the computation results. Also, the results given by non gas model are compared with those by gas model. Using the transient ellipsometry techniques, we studied the dynamic orientation behaviour of chromophores 4,4' n pentylcyanobiphenyl (5CB) in the photorefractive composite consisting of the polymer (N vinylcarbazole) (PVK) doped with 5CB and C 60 . The dependencies of the orientation parameters on the applied electric field and temperature are measured. Comparisons between the theoretical and the experimental results showed that the non gas model is reasonable.