Aggregation Behavior of Doubly Thermoresponsive Polysulfobetaine-b-poly(N-isopropylacrylamide) Diblock Copolymers
Aggregation Behavior of Doubly Thermoresponsive Polysulfobetaine-b-poly(N-isopropylacrylamide) Diblock Copolymers
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DOI：
10.1021/acs.macromol.6b01186
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发表时间：
2016-08
期刊：
影响因子：
5.5
通讯作者：
N. Vishnevetskaya;Viet Hildebrand;Bart‐Jan Niebuur;Isabelle Grillo;Sergey K. Filippov;A. Laschewsky;P. Müller‐Buschbaum;C. Papadakis
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文献类型：
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作者：
N. Vishnevetskaya;Viet Hildebrand;Bart‐Jan Niebuur;Isabelle Grillo;Sergey K. Filippov;A. Laschewsky;P. Müller‐Buschbaum;C. Papadakis
采用RAFT聚合法制备了两性离子聚磺基甜菜碱（PSPP）嵌段和非离子聚n -异丙基丙烯酰胺（PNIPAM）嵌段的2重热敏二嵌段共聚物PSPP430-b-PNIPAM200。在水溶液中，相应的均聚物PSPP和PNIPAM分别具有较高和较低的临界溶液温度（UCST和LCST）行为。双嵌段共聚物在水溶液中表现出热诱导的“精神分裂”聚集行为。此外，两性离子PSPP块的云点对离子强度和盐的性质的离子敏感性提供了创建可切换系统的可能性，该系统对温度、电解质类型和浓度的变化都有敏感的响应。用浊度法和小角中子散射（SANS）研究了D2O中二嵌段共聚物溶液的相行为和自组装结构对温度和电流的依赖。
A 2-fold thermoresponsive diblock copolymer PSPP430-b-PNIPAM200 consisting of a zwitterionic polysulfobetaine (PSPP) block and a nonionic poly(N-isopropylacrylamide) (PNIPAM) block is prepared by successive RAFT polymerizations. In aqueous solution, the corresponding homopolymers PSPP and PNIPAM feature both upper and lower critical solution temperature (UCST and LCST) behavior, respectively. The diblock copolymer exhibits thermally induced “schizophrenic” aggregation behavior in aqueous solutions. Moreover, the ion sensitivity of the cloud point of the zwitterionic PSPP block to both the ionic strength and the nature of the salt offers the possibility to create switchable systems which respond sensitively to changes of the temperature and of the electrolyte type and concentration. The diblock copolymer solutions in D2O are investigated by means of turbidimetry and small-angle neutron scattering (SANS) with respect to the phase behavior and the self-assembled structures in dependence on temperature and el...