Photophysical properties and self-assembly of triblock copolymer with complexes of positively charged PDMAEMA and oppositely charged chromophores

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• 作者：Xueming Lian ; Fei Zhao ; Yuan Li ; Jun Wang ; Siming Li ; Hanying Zhao ; ^{hyzhao@nankai.edu.cn}
• 关键词：Triblock copolymer complex ; Self-assembly ; Photophysical properties
• 刊名：Polymer
• 出版年：2012
• 出版时间：17 April, 2012
• 年：2012
• 卷：53
• 期：9
• 页码：1906-1914
• 全文大小：1716 K

文摘

The self-assembly and photophysical properties of a triblock copolymer with complex mid-block in THF and aqueous solution were investigated in this research. Poly(poly(ethylene glycol) methyl ether methacrylate)-block-poly(2-(dimethylamino ethyl methacrylate)-block- poly(poly(ethylene glycol) methyl ether methacrylate) (PPEGMA-b-PDMAEMA-b-PPEGMA) triblock copolymer was synthesized by subsequent atom transfer radical polymerizations (ATRP) of DMAEMA and PEGMA. The PDMAEMA blocks were quaternized by a reaction with iodomethane. The complex of the positively charged PDMAEMA chain unit and sodium salt of 1-pyrenebutyric acid was prepared by mixing equimolar amount of the two components in THF/water mixture. Transmission electron microscopy and fluorescence technique results show that the triblock copolymer chains self-assemble into micelles in THF at high concentration. The critical aggregation concentration (CAC) of the triblock copolymer in THF determined by fluorescence technique is 6.8?¡Á?10^??M. The triblock copolymer was also able to self-assemble into micelles in water. The value of CAC of the triblock copolymer in water is 2.0?¡Á?10^??M. The photophysical properties and self-assembly structures of the triblock copolymer in aqueous solutions were influenced by added sodium chloride. After salt addition, a transition of the assembled structures from micelles to hollow structures was observed.