Au/聚4-乙烯基吡啶-b-聚乙二醇嵌段聚合物刷的合成及其pH响应行为

doi:10.11944/j.issn.1000-0518.2019.04.180360

摘要/Abstract

摘要：

作为受限高分子体系的一个经典模型,高分子刷在胶体稳定、聚合物链的自组装以及摩擦学等方面具有潜在的应用价值。本文通过原子转移自由基聚合(ATRP)和点击化学(Click Chemistry)方法在金(Au)基底表面制备了pH响应性聚4-乙烯基吡啶-b-聚乙二醇(P4VP-b-PEG)嵌段聚合物刷。通过频率-耗散型石英微天平(QCM-D)、X射线光电子能谱(XPS)和原子力显微镜(AFM)等技术手段分别对Au/P4VP-b-PEG聚合物刷经不同pH值溶液处理后的形态变化、表面组成和表面形貌进行了进一步深入研究。结果表明,用不同pH值溶液处理P4VP-b-PEG嵌段聚合物刷后,该聚合物刷呈现刺激响应规律。当pH=1.5时,P4VP链段质子化,由于静电排斥作用使P4VP-b-PEG链段呈伸展构象;当pH=11.5时,P4VP链段去质子化,并且由于失去部分结合水,P4VP-b-PEG链段呈塌缩构象。

关键词: 聚合物刷, 刺激响应性, 原子转移自由基聚合, 点击化学

Abstract:

As a classical model of confined polymer systems, polymer brushes have potential applications in colloid stability, polymer self-assembly, tribology, and so on. We present herein a combination of atom transfer radical polymerization(ATRP) and click chemistry method to synthesize pH-responsive poly(4-vinylpyridine-b-polyethylene glycol)(P4VP-b-PEG) block polymer brushes on gold(Au) substrates. The changes of the morphologies, surface chemical composition and surface roughness of the as-prepared Au/P4VP-b-PEG polymer brushes treated by different pH solutions were further studied by frequency-dissipation quartz microbalance(QCM-D), X-ray photoelectron spectroscopy(XPS) and atomic force microscopy(AFM), respectively. The results showed that P4VP-b-PEG block polymer brushes treated with different pH solutions exhibited stimuli-response behaviors. At pH=1.5, the P4VP segment was protonated, and the P4VP-b-PEG chain exhibited stretching conformation due to electrostatic repulsion. At pH=11.5, the P4VP segment was deprotonated, and the P4VP-b-PEG segment collapsed due to the loss of partial binding water.

Key words: polymer brush, stimuli responsive, atom transfer radical polymerization, click chemistry

杨木泉, 肖凌宇, 张旋, 颜悦. Au/聚4-乙烯基吡啶-b-聚乙二醇嵌段聚合物刷的合成及其pH响应行为[J]. 应用化学, 2019, 36(4): 431-439.

YANG Muquan, XIAO Lingyu, ZHANG Xuan, YAN Yue. Fabrication of Poly(4-Vinylpyridine-b-Polyethylene Glycol) Diblock Copolymer Brushes from Au Surfaces and Their pH Responsive Behavior[J]. Chinese Journal of Applied Chemistry, 2019, 36(4): 431-439.

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