两种侧链偶氮聚电解质自组装膜中生色团取向研究

用偏振紫外光谱研究了两种侧链偶氮聚电解质静电逐层自组装膜中偶氮生色团的初始取向 .讨论了不同的组装条件对自组装膜中偶氮生色团取向的影响 .进一步探讨了偶氮聚电解质自组装膜的结构特点 .研究表明 ,侧链偶氮聚电解质自组装膜中的偶氮生色团存在一定程度的面内取向 ,自组装的各种影响条件和聚合物结构等 (pH值、侧链柔性间隔基团长度、以及偶氮生色团官能度等 )与自组装膜中偶氮生色团的面内取向程度存在一定的相关性 .通过研究偶氮生色团的取向和影响因素 ,可以深入认识侧链偶氮聚电解质的自组装行为

ORIENTATION OF AZOBENZENES IN AZO POLYELECTROLYTE SELF-ASSEMBLED MULTILAYERS

Orientation of azobenzene units in self assembled multilayer films of two side chain azo polyelectrolytes was investigated by using polarized UV Vis absorption spectroscopy.Several factors,such as the pH value of dipping soluti o n,the length of flexible spacers and the functional degree of azo chromophores, on the orientation of chromophores in films were investigated.The results sho w ed that the azo chromophores are prior to an in plane orientation.The factors i nfluencing polyelectrolyte conformation in the self assembly solutions have sig nificant influences on the orientation degree of azobenzene groups.Increasing th e pH value or the length of flexible spacers and decreasing the degree of functi onalization can cause an increase of the orientation degree of azobenzene chromo phores in the multilayers.Among the three factors,the results showed that the pH v alue of dipping solution has the most important influence on the orientation of azo chromo phores in self assembled films because it can directly affect the constellation of azo polyelectrolytes in solution.By adjusting the pH value,the orientation degree of azo chromophores in self assembled films can be controlled in a large scale range.