文献类型：期刊文献

英文题名：Synthesis via RAFT Polymerization of Tadpole-Shaped Organic/Inorganic Hybrid Poly(acrylic acid) Containing Polyhedral Oligomeric Silsesquioxane (POSS) and Their Self-assembly in Water

作者：Zhang, Weian[1,2];Fang, Bing[1];Walther, Andreas[1];Mueller, Axel H. E.[1]

机构：[1]Univ Bayreuth, D-95440 Bayreuth, Germany;[2]E China Univ Sci & Technol, Dept Chem, Adv Mat Lab, Shanghai 200237, Peoples R China

年份：2009

卷号：42

期号：7

起止页码：2563

外文期刊名：MACROMOLECULES

收录：;EI(收录号：20092412130264);WOS:【SCI-EXPANDED(收录号:WOS:000264992300037)】；

基金：This work was supported by the Alexander von Humboldt Foundation. W.Z. also acknowledges support by the National Natural Science Foundation of China (No. 50503013). We thank Ms. Anja Goldmann for the MALDI-TOF NIS measurements and Mr. Ezzat Khan (Inorganic Chemistry) for performing the ²⁹Si NMR measurements. W.Z. acknowledges Mr. Youyong Xu and Mr. Jiayin Yuan for help and discussions.

语种：英文

外文关键词：Chains - Free radical polymerization - Polydispersity - Aggregates - Self assembly - Living polymerization - High resolution transmission electron microscopy - Dynamic light scattering - Carboxylic acids

摘要：Tadpole-shaped inorganic/organic hybrid poly(tert-butyl acrylate) was prepared by RAFT polymerization of tert-butyl acrylate (tBA) using a POSS-containing chain transfer agent (CTA). The polymerization kinetics showed a pseudofirst-order behavior with a short induction period; the number-average molecular weights linearly increase with conversion. In conjunction with low polydispersity (PDI < 1.3), this confirms a controlled polymerization. POSS-PtBA was further hydrolyzed into amphiphilic, tadpole-shaped poly(acrylic acid) (POSS-PAA). The self-assembly behavior of POSS-PAA in aqueous Solution at pH = 8.5 was investigated by transmission electron microscopy (TEM) as well as static and dynamic light scattering (SLS and DLS). The results show that POSS-PAA self-assembles in water into rather large aggregates where the POSS moieties are dispersed in the particle. The size (average radius approximate to 60 nm by DLS) is nearly independent of the chain length of PAA. The aggregates are pH-responsive, contracting when decreasing pH front 8.5 to 4.