文献类型：期刊文献

英文题名：Tuning self-assembly and photo-responsive behavior of azobenzene-containing triblock copolymers by combining homopolymers

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

机构：[1]E China Univ Sci & Technol, Shanghai Key Lab Adv Polymer Mat, Key Lab Ultrafine Mat, Minist Educ,Sch Mat Sci & Engn, Shanghai 200237, Peoples R China;[2]E China Normal Univ, Dept Chem, Shanghai 200241, Peoples R China

年份：2013

卷号：24

期号：8

外文期刊名：NANOTECHNOLOGY

收录：;EI(收录号：20130716018705);WOS:【SCI-EXPANDED(收录号:WOS:000314818300008)】；

基金：This work was supported by National Natural Science Foundation of China (51103044, 21174038 and 50925308). Support from Projects of Shanghai Municipality (11QA1401600, 13ZZ041 and 12JC1403102) and Fundamental Research Funds for the Central Universities (20100074120001, NCET-12-0857 and WD1213002) is also appreciated.

语种：英文

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

摘要：The self-assembly behavior of azobenzene-based triblock copolymers poly(ethylene oxide)-block-polystyrene-block-poly[6-(4-methoxy-4'-oxy-azobenzene) hexyl methacrylate] (PEO-b-PS-b-PMMAZO) and their mixtures with PS or PMMAZO homopolymers was studied by means of transmission electron microscopy, scanning electron microscopy, laser light scattering and UV-vis spectrophotometry. It was found that pure block copolymers self-assembled into spherical micelles with core-shell structures. The addition of PS or PMMAZO homopolymers can not only increase the aggregate size but also have a significant influence on the photo-isomerization behavior and photo-deformation behavior of the aggregate. The photo-isomerization study revealed that a complete trans-cis or cis-trans isomerization of azobenzene chromophores can be acquired when irradiated with UV or visible light for polymers both in organic solutions and in micelles. The photo-isomerization rate of azobenzene chromophores increases when PS homopolymers were incorporated into micelles, while with the addition of PMMAZO homopolymers, it decreases. The photo-induced elongation of the aggregates by irradiation of a linearly polarized laser was observed for all the samples, and the deformation degree increases with the weight fraction of azobenzene groups in the parent copolymers, as well as the PMMAZO content for the mixture micelles.