基于二维单层功能纳米片的取向性水凝胶的原位构筑及其性能研究

Inorganic–organic hydrogel is one of the most active and rapid developing research fronts in materials science and engineering, and the important research results in this field have been frequently published in Nature in recent years. Among many research sub-branches, the study on fabricating functional and anisotropic hydrogels is one key research direction for the future development of hydrogels. The functionalization can give hydrogels new features, while the anisotropy in hydrogels can endow the hydrogels with significant changes in properties and behaviors. In 2013, the applicant reported a novel gigantic monolithic crystalline swelling of layered materials on Nature Communication, whose sheet-to-sheet gallery spacing can be instantly increased 100-fold in one direction from 0.9 nm to 90 nm. The finding provides an excellent material platform for the design of functionalized, anisotropic hydrogels. In this project, we will replace traditional organic crosslinking agent or disordered inorganic crosslinking agent with the gigantic monolithic crystalline swollen layered phase for the fabrication of anisotropic and functional hydrogels. This modification could bring unprecedented physical and chemical properties to the hydrogels. The study provides a new and simple route to the design and application exploration of new types of hydrogels and brings numerous new possibilities.

有机/无机纳米复合水凝胶是目前材料科学与工程领域发展最为活跃的研究前沿之一，《自然》杂志近几年连续发表此领域的重要研究成果。复合水凝胶的功能化、取向化将是此领域内下一步的重点研究方向之一，功能化可赋予水凝胶特殊的新性能，取向化可使水凝胶的物理化学性质发生显著变化。申请者于2013年在国际顶尖学术杂志《自然—通讯》报道了一种奇特的可吸水并体积膨胀的层状氧化钛纳米单晶，膨胀量可达100倍，含水量高达97%，这为构筑功能性、取向性的复合水凝胶提供了一个非常理想的起点。本项目基于申请者前期的研究成果，拟将这种可超大体积膨胀的氧化钛纳米单晶引入到有机/无机纳米复合水凝胶的结构设计中,代替传统的有机交联剂，设计合成基于无机二维纳米片的、取向性的新型功能纳米复合水凝胶，从而赋予水凝胶前所未有的各向异性的物理化学性能和功能特性。该项研究对于水凝胶材料的设计及应用探索提供了一种新的思路和途径。

将水凝胶功能化具有重要意义，无机二维纳米片材料具有厚度小、水溶性好等优点，可以作为无机交联剂引入到水凝胶的结构设计中，赋予水凝胶丰富的功能特性及各向异性等物理化学特性。本项目控制合成了多种二维单层纳米片材料，包括过渡金属氧化物、碳化物等；利用无机纳米片与有机聚合物之间的特定相互作用力，设计各种复合结构，包括氧化锰纳米片/聚苯胺，氧化钛纳米片/壳聚糖，碳化钛-氧化锰纳米片/四甲基氢氧化铵等；研究有机/无机成分界面对性能的增强作用；为了适应现代电子器件飞速发展的需求，将这些复合结构加工成一维纤维或二维纸状，探索了将这些复合结构进一步应用于智能柔性可穿戴器件的可能性。