title: Synthesis of poly(N-isopropylacrylamide)-b-poly(2-vinylpyridine) block copolymers via RAFT polymerization and micellization behavior in aqueous solution.
abstract: Poly(N-isopropylacrylamide)-b-poly(2-vinylpyridine) (PNIPAM-b-P2VP) block copolymers were synthesized for the first time via reversible addition-fragmentation chain transfer (RAFT) polymerization in the presence of S-1-dodecyl-S(')-(a,a(')-dimethyl-a('')-acetic acid)trithiocarbonate as chain transfer agent (CTA) and 2,2(')-azobis(isobutyronitrile) as initiator. Both pH- and thermo-induced micellization behavior of the PNIPAM(59)-b-P2VP(102) block copolymer in dilute aqueous solution was investigated by pyrene fluorescence, dynamic and static light scattering, transmission electron microscopy and (1)H NMR. The results show that the critical aggregation pH value of the block copolymer is around 5 and the critical aggregation temperature of the block copolymer is around 42 degrees C. A reversible transition between P2VP-core and PNIPAM-core micelles can be observed through an intermediate unimer state in aqueous solution.
authors.affiliation: Key Laboratory of Functional Polymer Materials of Ministry Education, Department of Chemistry, Nankai University, Tianjin 300071, China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Zeng
authors.forename: Keyu
authors.initials: K
authors.lastname: Shi
authors.forename: Yuying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xuehui
authors.initials: X
authors.lastname: Sun
authors.forename: Lin
authors.initials: L
authors.lastname: Deng
authors.forename: Xianzhi
authors.initials: X
authors.lastname: Guo
authors.forename: Zongjie
authors.initials: Z
authors.lastname: Du
authors.forename: Baolong
authors.initials: B
authors.lastname: Zhang