Royes Jorge, Provenzano Clementina, Pagliusi Pasquale, Tejedor Rosa M, Piñol Milagros, Oriol Luis
Institute of Materials Science of Aragon (ICMA), University of Zaragoza-CSIC, Faculty of Science, Pedro Cerbuna 12, 50009, Zaragoza, Spain.
Macromol Rapid Commun. 2014 Nov;35(21):1890-5. doi: 10.1002/marc.201400355. Epub 2014 Sep 25.
The large and reversible photoinduced linear and circular birefringences in azo-compounds are at the basis of the interest in these materials, which are potentially useful for several applications. Since the onset of the linear and circular anisotropies relies on orientational processes, which typically occur on the molecular and supramolecular length scale, respectively, a circular birefringence at least one order of magnitude lower than the linear one is usually observed. Here, the synthesis and characterization of an amorphous polymer with a dimeric repeating unit containing a cyanoazobenzene and a cyanobiphenyl moiety are reported, in which identical optical linear and circular birefringences are induced for proper light dose and ellipticity. A pump-probe technique and an analytical method based on the Stokes-Mueller formalism are used to investigate the photoinduced effects and to evaluate the anisotropies. The peculiar photoresponse of the polymer makes it a good candidate for applications in smart functional devices.
偶氮化合物中存在的大的且可逆的光致线性和圆双折射现象是人们对这些材料感兴趣的基础，这些材料在多个应用领域具有潜在用途。由于线性和圆各向异性的产生依赖于取向过程，这通常分别发生在分子和超分子长度尺度上，因此通常观察到的圆双折射比线性双折射至少低一个数量级。在此，报道了一种具有含氰基偶氮苯和氰基联苯部分的二聚重复单元的非晶态聚合物的合成与表征，其中对于适当的光剂量和椭圆率会诱导出相同的光学线性和圆双折射。采用泵浦 - 探测技术和基于斯托克斯 - 穆勒形式主义的分析方法来研究光致效应并评估各向异性。该聚合物独特的光响应使其成为智能功能器件应用的良好候选材料。
