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。本课题以制备可自修复高强度水凝胶为目的，从凝胶的网络结构设计入手，提出一种结构新颖、制备便捷的“多重键合交联网络凝胶”新概念。从共价、氢键、配位（离子）键、疏水作用等键合中，将多种键合组合起来在聚合物凝胶网络中构筑具有不同强度的多重多层级交联点，尤其是引入动态交联键。由此获得的凝胶体系同时拥有多种不同层级键，在外力作用下多层级键的逐次破坏可以有效地耗散能量，动态键的破坏—重组又实现了凝胶网络的均匀化。这种多级能量耗散机制已经被证明能够有效地提高凝胶材料的力学性能。本项目着重探讨和阐明该凝胶的强韧化机理，多层级键的协同作用对凝胶强韧化的贡献。通过改变、调整纳米结构（维数和尺度）和网络分子结构，如接枝和嵌段共聚物的相分离结构来构筑金属离子的传输通道，用以加强离子键合，有针对性地制备超高强水凝胶，开拓水凝胶功能应用的新途径

Many researchers have shown great interest in fabricating hydrogels with ultrahigh mechanical strength recently, which is beneficial to broadening the application fields of hydrogels. In this research, we aim to greatly improve the mechanical strength of hydrogels. From the viewpoint of gel network structure, we propose a facile, novel strategy to design and build “single network gel with hierarchical cross-linkings” by a combination of covalent bonds, hydrogen bonds, ionic bonds and hydrophobic interactions. First, we prepare and modify nanoparticles with different dimensions and sizes and then graft a large quantity of water-soluble polymer chains from their surfaces to form gelators. By introducing a combination of covalent bonds, hydrogen bonds, ionic bonds and hydrophobic interactions to form hierarchical cross-linkings, super tough hydrogels will be obtained. Under tension, the physical cross-linkings in the resulting hydrogels can dynamically break-recombine to dissipate energy and the network chains will be rearranged and homogenized during the break-recombination process. So the stress will be shared and homogenized by hierarchical cross-linkings. Therefore, hydrogels with ultrahigh strength and reversible stretchability can be attained. Our preliminary research results indicate that the hierarchically cross-linked hydrogels have superior strength and toughness. In this project, the study will focus on how to effectively introduce hierarchical cross-linkings and the toughening mechanism of the hydrogels. As a result, we expect to develop their applications in biomedical, drug delivery, sensors and energy materials fields.