Royes Jorge, Oriol Luis, Tejedor Rosa M, Piñol Milagros
Departamento de Química Orgánica, Facultad de Ciencias, Instituto de Ciencia de Materiales de Aragón (ICMA), Universidad de Zaragoza-CSIC, c/ Pedro Cerbuna 12, 50009 Zaragoza, Spain.
UMR 8640, CNRS, École Normale Superieure Département de Chimie, 24 rue Lhomond, 75005 Paris, France.
Polymers (Basel). 2019 May 15;11(5):885. doi: 10.3390/polym11050885.
This paper describes the synthesis, thermal characterization and optical properties of liquid crystalline homopolymers and block copolymers with a repeating unit consisting of two functional units, with at least one of them being an azobenzene. Films of these polymers have been irradiated with circularly polarized light at room temperature, evaluating the intensity of the photoinduced chiral signal and its temporal stability upon storage. The paper also explores two different strategies to restrict the relaxation of the photoinduced order. Firstly, block copolymers have been prepared to confine the photoaddressable segments into nanoscopic domains where relaxation should be restricted. Secondly, an alternative homopolymer has been synthesized where the repeating unit combines two chromophores that can be separately photoaddressed, an azobenzene unit to efficiently photoinduce chirality and a cinnamate to fix the chiral signal by photocrosslinking.
本文描述了具有由两个功能单元组成的重复单元的液晶均聚物和嵌段共聚物的合成、热表征和光学性质，其中至少有一个功能单元是偶氮苯。这些聚合物的薄膜在室温下用圆偏振光照射，评估光诱导手性信号的强度及其储存时的时间稳定性。本文还探索了两种不同的策略来限制光诱导有序的弛豫。首先，制备嵌段共聚物将可光寻址段限制在纳米级域中，在该域中弛豫应受到限制。其次，合成了一种替代均聚物，其重复单元结合了两个可分别进行光寻址的发色团，一个偶氮苯单元以有效光诱导手性，一个肉桂酸酯通过光交联固定手性信号。
