Photoresponsive behavior of two well-defined azo polymers with different electron-withdrawing groups on push–pull azo chromophores
Photoresponsive behavior of two well-defined azo polymers with different electron-withdrawing groups on push–pull azo chromophores
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DOI：
10.1016/j.dyepig.2013.05.006
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发表时间：
2013-10
影响因子：
4.5
通讯作者：
Yu Zhu;Yu-Qian Zhou;Xiaogong Wang
中科院分区：
文献类型：
--
作者：
Yu Zhu;Yu-Qian Zhou;Xiaogong Wang
通过RAFT聚合合成了两种具有强推拉偶氮发色团的甲基丙烯酸酯基偶氮聚合物。该聚合物在偶氮发色团的4位上含有氰基和羧基作为吸电子基团。聚合物表现出显着不同的光响应特性的所有光驱动的运动水平。当用532 nm的线偏振激光束照射时，含氰基偶氮苯的聚合物相对于含羧基偶氮苯的聚合物表现出快速的双折射增长。当光被切断时，与其对应物相比，观察到含羧基偶氮苯的聚合物的取向衰减低得多。在用这两种波长的干涉激光束照射时，在含氰基偶氮苯的聚合物的膜上形成表面浮雕光栅振幅，并且表面浮雕光栅振幅基本上大于羧基取代的聚合物的表面浮雕光栅振幅。当用488和532 nm的均匀激光束照射聚合物膜时，仅用532 nm的光照射检测到含氰基偶氮苯的聚合物的自结构化表面图案。
Two well-defined methacrylate-based azo polymers bearing strong push–pull azo chromophores were synthesized by RAFT polymerization. The polymers contain cyano and carboxyl as electron-withdrawing groups at 4-positions of the azo chromophores. The polymers exhibited significantly different photoresponsive properties on all light-driven motion levels. When irradiated with a linearly polarized laser beam at 532 nm, the cyanoazobenzene-containing polymer showed rapid birefringence growth relative to that of the carboxylazobenzene-containing polymer. When the light was switched off, a much lower orientation decay was observed for the carboxylazobenzene-containing polymer compared with its counterpart. Upon irradiation with the interfering laser beams at these two wavelengths, surface-relief-grating amplitude formed on the film of the cyanoazobenzene-containing polymer and was substantially larger than that for the carboxyl substituted polymer. When the polymer films were irradiated with a homogenous laser beam at 488 and 532 nm, self-structured surface pattern was only detected for the cyanoazobenzene-containing polymer with the 532 nm light irradiation.