自修复智能水凝胶的分子设计及机理分析

Smart hydrogels are the subject of increasing interest due to their eco-friendly, biocompatible, and ability to undergo desirable and reversible transitions in microstructure or macrostructure upon small changes in their environment. Developing self-healing smart hydrogels possessing high-performance features are expected to be a new field of research. Here, we develop a novel and simple method for introducing self-healing property into the smart hydrogels, in which, the self-immolative polymer, possessing "domino effect" when depolymerized, was designed and embedded into smart hydrogel. Such self-immolative polymer would be degraded gradually to release the matrix carried when subject to the particular stimulate. This matrix would react with the substance released by the damaged hydrogel, re-constructing the new structure of the hydrogel. The damaged hydrogel would therefore be self-healed. The innovation of the present project is to invert the environmental stimulate damaging the hydrogel into the inner force to self-heal the hydrogel. Of particular interest is that by accurate design such stimulate can be strain, pH, temperature, light and so forth. Thus we can obtain the real self-healing smart hydrogel that would be applied in the complicated environmental and living organisms.

制备绿色环保、具有良好生物相容性并能对光、热、pH、酶等外界刺激产生响应的智能型水凝胶是当今科学研究的热点，将自修复性能引入到智能型水凝胶设计之中是非常值得探索的新领域。本项目旨在发展一种制备自修复智能型水凝胶的分子设计方法，其具体思路是将经过设计的、自降解时具有多米洛骨牌效应的高分子"包埋"在智能型水凝胶中，利用该高分子在受到特定外部刺激时逐步降解释放出尾部的携带基质，与受到同样刺激导致水凝胶受到损伤时释放出的物质，进行化学反应和重组，从而对水凝胶局部结构的损伤进行自修复。本项目设计的创新之处是把导致凝胶产生损伤的外部刺激，转换为水凝胶产生自修复的内在驱动力，只要精确设计，这种刺激可以是应力、酶、pH﹑温度、光﹑超声等任何一种，从而获得真正意义上的能够在复杂环境和生物体内实际应用的自修复智能型水凝胶。

制备绿色环保、具有良好生物相容性并能对光、热、pH、酶等外界刺激产生响应的智能型水凝胶是当今科学研究的热点，将自修复性能引入到智能型水凝胶设计之中是非常值得探索的新领域。本项目通过各种不同相互作用的引入及巧妙而精确的分子设计，如引入高分子与表面活性剂、环糊精、纳米粘土和金属离子等之间相互作用，或者将功能性单体如两性离子单体，温敏单体、疏水单体和具有动态共价键或氢键相互作用单体引入到高分子设计中，或者借助于特殊的实验手段如原位聚合或者包埋技术，制备了一系列对光、热、pH、酶等外界刺激产生响应的自修复智能水凝胶。与此同时我们还特别注意将一些特殊性质如高强度、热塑性、多重刺激响应性、二氧化碳响应性、可注射性和形状记忆特性引入到自修复智能水凝胶设计之中，为自修复智能水凝胶在复杂环境和生物体内实际应用奠定了基础。