Temperature Driven Self-Assembly of a Zwitterionic Block Copolymer That Exhibits Triple Thermoresponsivity and pH Sensitivity

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• 作者：Zulma A. Jim茅nez ; Ryo Yoshida
• 刊名：Macromolecules
• 出版年：2015
• 出版时间：July 14, 2015
• 年：2015
• 卷：48
• 期：13
• 页码：4599-4606
• 全文大小：462K
• ISSN：1520-5835

文摘

We report a zwitterionic block copolymer composed of N-isopropylacrylamide and N,N-dimethyl-N-(3-(methacrylamido)propyl)ammoniopropanesulfonate monomers which self-assembles into different structures depending on the solution temperature. As the temperature is increased from 20 to 70 掳C, the solubility of the polymer switches direction from insoluble to soluble to insoluble to soluble. During this process, the polymer self-assembly changes from polymersomes to micelles. These extraordinary transitions are possible because of the hydrophilic鈥揾ydrophobic ratio of the polymer blocks and the presence of a carboxyl end group attached to the end of the poly(N-isopropylacrylamide) chain. Additionally, one of these transitions can be controlled by the pH of the solution thanks to the protonation鈥揹eprotonation of the carbonyl and the charge neutralization of the ammonium moieties. The present work opens the possibility of designing polymers with temperature driven self-assembly properties that could be used for biomedical applications.