pH-Responsive Micellization of Amine-Containing Cationic Diblock Copolymers Prepared by Reversible Addition-Fragmentation Chain Transfer (RAFT) Radical Polymerization
pH-Responsive Micellization of Amine-Containing Cationic Diblock Copolymers Prepared by Reversible Addition-Fragmentation Chain Transfer (RAFT) Radical Polymerization
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DOI：
10.1295/polymj.37.480
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发表时间：
2005-07
期刊：
影响因子：
2.8
通讯作者：
S. Yusa;Y. Konishi;Y. Mitsukami;Tohei Yamamoto;Y. Morishima
中科院分区：
文献类型：
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作者：
S. Yusa;Y. Konishi;Y. Mitsukami;Tohei Yamamoto;Y. Morishima
采用基于可逆加成-断裂链转移（RAFT）的可控自由基聚合方法，合成了一系列不同嵌段长度的聚（[3-（甲基丙烯酰氨基）丙基]三甲基氯化铵）-聚（2-（二乙基氨基）乙基甲基丙烯酸酯）（pMAPTACm-DEAEMan）嵌段共聚物。该二嵌段共聚物具有窄的分子量分布，重均分子量与数均分子量之比（Mw/Mn）为1.04-1.05。的基础上，1H NMR，准弹性光散射（QELS），静态光散射（SLS），和荧光探针数据，这些嵌段共聚物表现出可逆的胶束形成和解离在水溶液中诱导的pH值变化。的流体动力学半径（Rh）和表观分子量的二嵌段共聚物的pH值7附近突然增加，随着pH值的增加，胶束形成在碱性pH值的指示。N-苯基-1-萘胺（PNA）探针的荧光光谱表明，疏水分子，如PNA纳入到胶束的疏水核心。当胶束在pH≤7时解离时，PNA探针释放到本体水相中。在pH>7时荧光探针的捕获和在pH≤7时荧光探针的释放可逆地发生，这是由于pH变化时胶束的形成和解离。
A series of poly([3-(methacryloylamino)propyl]trimethylammonium chloride)-block-poly(2-(diethylamino)ethyl methacrylate) (pMAPTACm–DEAEMAn) of different block lengths were prepared by controlled radical polymerization based on reversible addition-fragmentation chain transfer (RAFT). The diblock copolymers have a narrow distribution in their molecular weights, the ratios of weight- and number-average molecular weights (Mw/Mn) being in the range of 1.04–1.05. On the basis of 1H NMR, quasielastic light scattering (QELS), static light scattering (SLS), and fluorescence probe data, these diblock copolymers exhibited reversible micelle formation and dissociation in aqueous solutions induced by a pH change. The hydrodynamic radius (Rh) and apparent molecular mass for the diblock copolymer increased abruptly near pH 7 with increasing pH, indicative of the micelle formation at basic pHs. Fluorescence spectra for N-phenyl-1-naphthylamine (PNA) probes suggested that hydrophobic molecules such as PNA were incorporated into hydrophobic cores in the micelle. PNA probes were released into the bulk water phase when the micelle was dissociated at pH≤7. The capture of the fluorescence probe at pH>7 and its release at pH≤7 occur reversibly as a result of the formation and dissociation of the micelle upon pH change.