title: Gradient structure-induced temperature responsiveness in styrene/methyl methacrylate gradient copolymers micelles.
abstract: In this work, micelles are formed by gradient copolymer of styrene and methyl methacrylate in acetone-water mixture and their temperature responsiveness is investigated in a narrow range near room temperature. Three different kinds of structural transitions could be induced by temperature: unimers to micelle transition, shrinkage/stretching of micelles, and morphological transition from spherical micelles to vesicles. In addition, a model analysis on the interface of gradient copolymer micelle is made to better understand these phenomena. It is found that both position and composition of the interface could alter in response to the change in temperature. According to the experiments and model analysis, it is proposed that temperature responsiveness might be an intrinsic and universal property of gradient copolymer micelles, which only originates from the gradient structure.
authors.affiliation: State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, 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: D008768:Methylmethacrylates / Q000737:chemistry*; D008823:Micelles; D015394:Molecular Structure; D011137:Polystyrenes / Q000737:chemistry*; D013696:Temperature
chemical_list: D008768:Methylmethacrylates; D008823:Micelles; D011137:Polystyrenes; C032043:styrene-methylmethacrylate copolymer
keywords: gradient copolymer; micelle; structural transitions; temperature responsiveness