文献类型：期刊文献

英文题名：Synthesis and self-assembly behaviors of four-arm star block copolymers poly(Ε-caprolactone)-b-poly(2-(diethylamino) ethyl methacrylate)) in aqueous solution

作者：Zhang, Xi[1]; Xiao, Yan[1]; Lang, Meidong[1]

机构：[1] Key Laboratory for Ultrafine Materials, Ministry of Education, East China University of Science and Technology, 130 Meilong Road, Shanghai 200-237, China

年份：2012

卷号：49

期号：2

起止页码：124

外文期刊名：Journal of Macromolecular Science, Part A: Pure and Applied Chemistry

收录：EI(收录号：20120514737154)

语种：英文

外文关键词：Self assembly - Atom transfer radical polymerization - Hydrophilicity - Ring opening polymerization - Dynamic light scattering - Solutions - Block copolymers - Critical micelle concentration

摘要：Four-arm star block polymers consisting of hydrophobic poly(Ε- caprolactone) (PCL) block and hydrophilic poly(2-(diethylamino) ethyl methacrylate)) (PDEAEMA) block were successfully synthesized by ring opening polymerization (ROP) and atom transfer radical polymerization (ATRP). Chain lengths of PDEAEMA segments were varied to obtain a series of star copolymers with different hydrophilic/hydrophobic ratio, which were desired for self-assembly study. Dynamic light scattering (DLS) and transmission electron microscopic (TEM) were used to study their self-assembly behavior. In the PBS solution with different pH value, the star polymers formed micelles or nanoparticles. Furthermore, the morphologies of the micelles were also pH-dependent. Critical micelle concentrations of star copolymers changed from 5.0 to 17.5 mg/L with the increase of hydrophilic block length or the pH decrease. Moreover, a steady increase was found on the micelles diameters when the pH decreased from 7.0 to 3.0. The low CMC value and slight changes on micelle diameter indicated that the micelle remained stable under the changing external stimulus. ? 2012 Taylor and Francis Group, LLC.