Reorganization of hydrogen bond network makes strong polyelectrolyte brushes pH-responsive.
Reorganization of hydrogen bond network makes strong polyelectrolyte brushes pH-responsive.
复制标题
氢键网络重组使聚电解质刷具有 pH 响应能力
DOI：
10.1126/sciadv.1600579
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发表时间：
2016-08
期刊：
影响因子：
13.6
通讯作者：
Liu G
中科院分区：
文献类型：
--
作者：
Wu B;Wang X;Yang J;Hua Z;Tian K;Kou R;Zhang J;Ye S;Luo Y;Craig VS;Zhang G;Liu G
强聚电解质刷的pH响应源于pH介导的氢键网络重组。弱聚电解质由于其丰富的pH响应特性而得到了广泛的实际应用。相比之下，强聚电解质长期以来被认为对 pH 不敏感，这是基于强聚电解质链的平均带电程度与 pH 无关这一公认事实。因此，强聚电解质在智能材料中的可能应用受到了严重限制。然而，我们证明强聚电解质刷 (SPB) 的几乎所有重要特性，如链构象、水合作用、刚度、表面润湿性、润滑性、粘附性和蛋白质吸附都对 pH 值敏感。 pH 响应源自接枝链之间链间氢键网络的重组，这是由 pH 介导的水合氢或氢氧化物与刷子的吸附-解吸平衡触发的。重组过程可以通过先进的和频产生振动光谱来确定。我们的研究结果不仅提供了对 SPB 基本特性的新认识，而且还揭示了用于构建 pH 响应材料的广泛构建模块家族。
The pH response of strong polyelectrolyte brushes originates from the pH-mediated reorganization of hydrogen bond network. Weak polyelectrolytes have found extensive practical applications owing to their rich pH-responsive properties. In contrast, strong polyelectrolytes have long been regarded as pH-insensitive based on the well-established fact that the average degree of charging of strong polyelectrolyte chains is independent of pH. The possible applications of strong polyelectrolytes in smart materials have, thus, been severely limited. However, we demonstrate that almost all important properties of strong polyelectrolyte brushes (SPBs), such as chain conformation, hydration, stiffness, surface wettability, lubricity, adhesion, and protein adsorption are sensitive to pH. The pH response originates from the reorganization of the interchain hydrogen bond network between the grafted chains, triggered by the pH-mediated adsorption-desorption equilibrium of hydronium or hydroxide with the brushes. The reorganization process is firmly identified by advanced sum-frequency generation vibrational spectroscopy. Our findings not only provide a new understanding of the fundamental properties of SPBs but also uncover an extensive family of building blocks for constructing pH-responsive materials.