Thermoresponsive Triblock Copolymer Aggregates Investigated by Laser Light Scattering

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• 作者：Xuechang Zhou ; Xiaodong Ye ; Guangzhao Zhang
• 刊名：Journal of Physical Chemistry B
• 出版年：2007
• 出版时间：May 17, 2007
• 年：2007
• 卷：111
• 期：19
• 页码：5111 - 5115
• 全文大小：98K
• 年卷期：v.111,no.19(May 17, 2007)
• ISSN：1520-5207

文摘

Narrowly distributed polystyrene-b-poly(N-isopropylacrylamide)-b-polystyrene (PS-b-PNIPAM-b-PS)triblock copolymer with trithiocarbonate group in the middle of PNIPAM block was synthesized by usingreversible addition fragmentation chain transfer (RAFT) polymerization. Such copolymer chains form a micelle-like aggregate with PNIPAM interlocking rings and associating PS blocks as the core and PNIPAM rings asthe corona. The hydrolysis of the trithiocarbonate group leads the rings in the corona to be cut into openlinear coils. Using laser light scattering, we have investigated the temperature-induced collapse of the aggregateswith the rings and coils in the corona. Our results reveal that the former shrink much less than the latter dueto the topological effect of PNIPAM blocks in the corona. On the other hand, the aggregates with long coilsexhibit a sharper collapse transition than those with shorter coils.