文献类型：期刊文献

英文题名：Self-assembly and photo-responsive behavior of novel ABC2-type block copolymers containing azobenzene moieties

作者：Wang, Yingying[1]; Lin, Shaoliang[1]; Zang, Minghui[1]; Xing, Yaohui[1]; He, Xiaohua[2]; Lin, Jiaping[1]; Chen, Tao[1]

机构：[1] Shanghai Key Laboratory of Advanced Polymeric Materials, East China University of Science and Technology, Ministry of Education, Shanghai 200237, China; [2] Department of Chemistry, East China Normal University, Shanghai 200062, China

年份：2012

卷号：8

期号：11

起止页码：3131

外文期刊名：Soft Matter

收录：EI(收录号：20121014836062)

语种：英文

外文关键词：Ethylene - Light scattering - Scanning electron microscopy - Azobenzene - High resolution transmission electron microscopy - Block copolymers - Polyethylene oxides - Self assembly

摘要：The self-assembly behavior and photo-responsive properties of novel azobenzene based copolymers poly(ethylene oxide) monomethyl ether-block- polystyrene-block-{poly[6-(4-methoxy-azobenzene-4′-oxy) hexylmethacrylate]}2 [MPEO-b-PS-b-(PMMAZO)2] with various block lengths of PMMAZO segments in aqueous media were studied by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM), laser light scattering (LLS) and UV-Vis spectrophotometry. It was found that the critical water content for the aggregate formation increases with the PMMAZO weight fraction. By tailoring the molecular structure and copolymer concentration, various self-assembled aggregates were obtained. At a lower concentration, all the copolymers self-assembled into simple vesicles. With increasing the polymer concentration, large compound vesicles were formed. The photo-sensitive properties of the formed aggregates were also studied. Upon irradiation with a polarized light, the aggregates were elongated. Large compound vesicles were found to deform into compact spindles with a very large axial ratio. ? 2012 The Royal Society of Chemistry.