偶氮染料光致异构过程的研究

Investigations of the Process of Photoinduced Isomerization on Azobenzene

摘要:

组建了偶氮染料的光致变色测试系统．进而用该系统研究了甲基红(MR)溶液和MR／聚甲基丙烯酸甲酯(PMMA)薄膜的光致异构过程。结果表明：增大激发光的光强与延长激发时间对促进MR分子光致异构具有等效作用。而且MR分子的光致异构过程对周围的空间位阻有很强的依赖性；偶氮分子因光致异构引起的光致变色实质上有光致异构为主的快过程和偶氮分子沿激光偏振方向取向为主的慢过程，取向状态在偶氮染料掺杂聚合物薄膜中可以长时间地保持。

Abstract:

A photochromism-testing system for azo dyes which has the characteristics of visualization,real-time and high accuracy,was estabilshed.Photochromism process of methyl red(MR) and MR/polymethyl methacrylate(PMMA) film were studied by using this system.And it was found that the effect of strengthening laser energy is similar to that of prolonging the excitation time,and the photochromism process of MR strongly depends on steric hindrance around azobenzene molecule.There actually are two parts in photochromism due to photoinduced isomerization of azobenzene:a fast one mainly accompanied by photoinduced isomerization and a slow one in which azobenzene molecules parallel laser polarization direction and the oriented state can remain a long time in the film of MR/PMMA.