155296-41-6Relevant academic research and scientific papers
Photoresponsive behavior of two well-defined azo polymers with different electron-withdrawing groups on push-pull azo chromophores
Zhu, Yu,Zhou, Yuqi,Wang, Xiaogong
, p. 209 - 219 (2013/10/21)
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
Photoresponsive diblock copolymers bearing strong push-pull azo chromophores and cholesteryl groups
Zhu, Yu,Zhou, Yuqi,Chen, Zhen,Lin, Ran,Wang, Xiaogong
scheme or table, p. 3566 - 3576 (2012/09/07)
A series of diblock copolymers bearing strong push-pull azo chromophores and cholesteryl groups on the respective blocks was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization. The liquid crystal phase structure, microphase-separated morphology, and photoresponsive properties of the block copolymers were investigated by using DSC, POM, AFM, XRD and laser irradiation. The results show that the cholesteryl block (PChEMA) forms smectic-A mesophase and the morphology depends on the length of the azo block (PAzoCN). When the azo block is short, such as PChEMA50-b-PAzoCN 7, no microphase separation can be identified. For PChEMA 50-b-PAzoCN28, PAzoCN appears as the hexagonal-packed nanocylinders embedded in the PChEMA matrix. When the azo block length further increases, the block copolymer PChEMA50-b-PAzoCN73 forms microphase-separated lamellae. The microphase separation shows no obvious restraint on the photoinduced orientation of the azo chromophores, but micron-scale mass transport of the photoresponsive PAzoCN block is inhibited by the phase confinement.
