title: Micellization of St/MMA gradient copolymers: a general picture of structural transitions in gradient copolymer micelles.
abstract: In this work, a gradient copolymer of styrene (St) and methyl methacrylate (MMA) is synthesized via reversible addition-fragmentation chain transfer living radical polymerization and its micellization behaviors in an acetone and water mixture are investigated by transmission electron microscopy, light scattering, and NMR spectroscopy. Three different kinds of transitions were found to coexist in a single system for the first time: a unimers to micelles transition, a star-like micelles to crew-cut micelles transition resulting from the shrinkage of micelles, and morphological transitions from spherical micelles to cylindrical micelles to vesicles. Our findings provide a general picture of structural transitions and relaxation processes in gradient copolymer micelles, which can lead to the development of novel materials and applications based on gradient copolymers.
authors.affiliation: State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Changchun, 130022, P. R. China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zheng
authors.forename: Haiying
authors.initials: H
authors.lastname: Huang
authors.forename: Tianbai
authors.initials: T
authors.lastname: He
mesh_terms: D008027:Light; D009682:Magnetic Resonance Spectroscopy; D008768:Methylmethacrylates / Q000737:chemistry*; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D012542:Scattering, Radiation
chemical_list: D008768:Methylmethacrylates; D008823:Micelles; D011108:Polymers; D011137:Polystyrenes; C032043:styrene-methylmethacrylate copolymer
keywords: gradient copolymers; micelles; relaxation processes; structural transitions