制备高强度水凝胶对于拓展其功能应用十分重要，近来深受国内外研究者的关注。本申请就是以提高水凝胶的强度为目的，从凝胶的网络结构入手，以新的策略设计并制备一种结构新颖的动态物理键和化学键耦合的物理纳米复合凝胶。本项目首先通过制备单分散的纳米粒子，再在其表面接枝上大量高分子链，形成凝胶因子，通过凝胶因子间分子链之间的氢键结合，形成物理凝胶。此时凝胶因子中的纳米粒子就自然地成为了化学交联点。由此形成的凝胶网络结构在拉伸条件下，可发生物理交联点的动态重排，耗散能量，同时导致网链的调整和均化，应力转由纳米粒子的化学交联点承载和分散，最终形成可重复高拉伸的超强凝胶。初步研究表明所制备的物理纳米复合凝胶，其强韧度均衡优异，是目前世界同类凝胶的最好结果之一。本课题拟通过改变纳米粒子含量、粒径、聚合物分子链长度等研究凝胶高强度实现的物理机制，制备具有多种功能的高强度凝胶，并开掘其应用。

Many researchers have showed great interest in fabricating hydrogels with ultrahigh mechanical strength recently, which is beneficial to broad the application field of them. In this research, we are aimed at improving greatly the mechanical strength of hydrogel. From the point of gel network structure, we design and build physcical nanocomposite hydrogels by coupling covalent bond and dynamic physical bond. First, we prepare monodispersed nanoparticles and graft a large quantity of water-soluble polymer chains from their surfaces to form gelators. Intermolecular hydrogen bonds could be formed between the polymer chains in gelators, which would result in the formation of physical gel. Thus, the nanoparticle in the gelator could spontaneously work as multifunctional chemical crosslinking point in the hydrogel. Under the condition of tension, the physical crosslinking points in gel network can dynamically disassociate-associate to dissipate energy and the disassociation-association of the physical crosslinking points could make the network chains rearranged and homogenized. So the stress will be shared and homogenized further by nanoparticles. Thus a physical hydrogel with ultrahigh strength and reversible high stretchability could be attained. Our priliminary research results indicated the prepared physical nanocomposite hydrogel with superior strength and toughness. In this research, the study will focus on the toughening mechanism of physical nanocomposite hydrogel and develop its application via tailoring the dosage and the diameter of nanoparticles and the length of polymer chains.