Autocatalytic Self-Sorting in Biomimetic Polymer

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• 作者：Kaiyi Zhou ; Hui Cao ; Pan Gao ; Zhigang Cui ; Yi Ding ; Yuanli Cai
• 刊名：Macromolecules
• 出版年：2016
• 出版时间：March 22, 2016
• 年：2016
• 卷：49
• 期：6
• 页码：2189-2196
• 全文大小：759K
• ISSN：1520-5835

文摘

Autocatalytic self-sorting in the biomimetic poly(cystamine methacrylamide hydrochloride) (PCysMA) is presented, whose units comprise lysine-mimetic alkylammonium ions and cystine-mimetic alkyl disulfide spacers. The block copolymer with poly(2-hydroxypropylmethacrylamide) was synthesized directly by RAFT in acidic water under visible light irradiation at 25 °C. Disulfide exchange can be initiated by the terminal thiolates as generated by alkalization-induced aminolysis. 65–67% CysMA units sort into hydrophobic polymer disulfides and water-soluble cystamine at pH 10.5. Moreover, intermediate reactions occur in the presence of copper ions, i.e., Cu(II)–NH₂ coordination, aminolysis, NH₂-to-SH substitution, and cupric-to-cuprous reduction in metal centers, thus autocatalytic self-sorting with essentially 100% conversion at pH 8.8. UV–vis spectroscopy, ¹H NMR, atomic absorption spectroscopy, and elemental analysis confirmed this ideal self-sorting. Dynamic light scattering and atomic force microscopy identified supramolecular-to-supracolloidal self-assembly with concomitant release of cystamine molecules and intermediate cuprous complexes. Such a self-sorting underlines an amazing prospect for the use of a single polymer to achieve artificial reaction complexity, hierarchy, and metabolic process, with minimal synthetic efforts.