Effect of Salt on the Micellization Kinetics of pH-Responsive ABC Triblock Copolymers
Effect of Salt on the Micellization Kinetics of pH-Responsive ABC Triblock Copolymers
复制标题
DOI：
10.1021/ma070978h
复制
发表时间：
2007-07
期刊：
影响因子：
5.5
通讯作者：
Zhiyuan Zhu;Jian Xu;Yueming Zhou;X. Jiang;S. Armes;Shiyong Liu
中科院分区：
文献类型：
--
作者：
Zhiyuan Zhu;Jian Xu;Yueming Zhou;X. Jiang;S. Armes;Shiyong Liu
采用停流光散射和荧光光谱法研究了聚（单甲基丙烯酸甘油酯）-b-聚（甲基丙烯酸二甲氨基乙酯）-b-聚（甲基丙烯酸二乙氨基乙酯）（PGMA-b-PDMA-b-PDEA）在盐（NaCl）存在下的pH诱导胶束化动力学，并与无盐溶液的结果进行了比较.在从pH 4跳到12时，该三嵌段共聚物形成由中心PDEA核组成的胶束，其由PDMA内壳和PGMA外冠屏蔽。对于胶束的形成，在存在或不存在盐的情况下，通过停流光散射记录的所有弛豫曲线可以很好地拟合双指数函数，导致快弛豫时间常数（τ1）和慢弛豫时间常数（τ2）。快速过程（τ1）与准平衡胶束的形成有关，而缓慢过程（τ2）与胶束形成-破裂有关，接近最终平衡状态。这两个过程发生得更慢…
The pH-induced micellization kinetics of poly(glycerol monomethacrylate)-b-poly(2-(dimethylamino)ethyl methacrylate)-b-poly(2-(diethylamino)ethyl methacrylate) (PGMA-b-PDMA-b-PDEA) in the presence of salt (NaCl) was investigated by stopped-flow light scattering and fluorescence, and the results were compared to those obtained with salt-free solutions. Upon jumping from pH 4 to 12, this triblock copolymer forms micelles that consist of a central PDEA core, shielded by a PDMA inner shell and a PGMA outer corona. For micelle formation in the presence or absence of salt, all relaxation curves recorded by stopped-flow light scattering can be well fitted with a double-exponential function, leading to a fast relaxation time constant (τ1) and a slow relaxation time constant (τ2). The fast process (τ1) is associated with the formation of quasi-equilibrium micelles, while the slow process (τ2) is associated with micelle formation−breakup, approaching the final equilibrium state. Both processes occur much more slowl...