侧链型偶氮聚合物液晶在不同波长激发条件下的光致取向

合成了聚甲基丙烯酸 (6 [4 (4 氰基偶氮苯 )苯氧基 ]己酯 ) (Poly(6 [4 (4 cyanophenylazo)phenoxy]hexylmethacrylate) (PM6ABCN) ) ,采用溶液挥发法在玻璃载片上成膜 ,研究了薄膜样品在Tg 温度以下的光致取向 .用波长分别为 36 6、40 0和 436nm的偏振光照射 ,发现PM6ABCN薄膜的光致取向过程不仅依赖于光的强度 ,还依赖所使用的偏振光的波长 .在低于Tg 的温度下 ,用波长为 40 0nm ,功率为 2 0mW cm2 的光照射 10 0s可以使样品的取向达到饱和 ,而用 36 6nm的光导致的取向程度要小于 40 0nm和 436nm的光 ,因为 36 6nm的光会在稳态时产生更多数目的cis异构体

PHOTOINDUCED ORIENTATION OF AZOBENZENE LIQUID CRYSTAL POLYMER UNDER IRRADIATION OF DIFFERENT LIGHT

Poly {6 [4 (4 cyanophenylazo)phenoxy]hexyl methacrylate} (PM6ABCN) was synthesized by the method reported before.After a simple casting film was made by removing the solvent on glass substrate,its photoinduced orientation behavior under temperature below T g was studied.After studying the photoinduced orientation behavior of PM6ABCN film under irradiation of light at 366?nm,400?nm,and 436?nm,it is found that the photoinduced orientation process not only depends on the light intensity,but also on the temperature and the wavelength of polarized light used.The maximum degree of orientation below T g can be obtained within 100 s under irradiation of polarized light of 20?mW/cm 2 at 400?nm,and irradiation at 366?nm causes a lower degree of orientation than that by irradiation at 400?nm and 436?nm because relatively more cis isomer was produced in the steady state.