生物大分子多尺度结构和动力学表征及仿生材料研究

Spider silk and silkworm silk are the most attractive biomaterials with extraordinary mechanical properties created by nature. Besides, chitin, cellulose and polysaccharides are the most abundant natural biomaterials have been widely used by human. Elucidating the precise control of the multi-scale structure and dynamics in biomacromolecules, and furthermore, developing biopolymer materials with high performance through multi-scale biomimetic methods, and achieving the high-performance for traditional synthetic polymers are important research topics in polymer science. In this project, multi-scale solid-state NMR in combination with other characterization techniques will be adopted to reveal the micro-phase separation structure and interface in high-performance natural biomaterials, the hydrogen bond interaction between water and biomacromolecules, the complex chain motion of the biomacromolecules, evolution of multi-scale structure and dynamics during the stretching process as well as its influence on the mechanical properties in different length and time scales, thus to establish the in-depth understanding of the structure-property relationships of high-performance biomaterials. On the basis of the above work and through multi-scale biomimetic molecular design, we will prepare a series of high-performance biomimetic polymer materials based on biopolymers and synthetic polymer with high density of hydrogen bonds, such as chitosan and multi-block polyurethanes. Our work will promote the fundamental research and industrial applications of high-performance biopolymer and polymer materials of our country.

蜘蛛丝和蚕丝等是自然创造的具有非凡力学性质的生物大分子材料，而甲壳素、纤维素和多糖等是自然界最丰富和被人类广为应用的天然高分子，阐明生物大分子中精确控制的多尺度结构与动力学，进而通过多尺度仿生来制备高性能生物基高分子材料、并实现传统合成聚合物的高性能化是高分子科学重要课题。本项目拟采用多尺度固体NMR并结合其它表征手段，在不同时空尺度上揭示高性能天然生物大分子中的微相分离结构与界面、水与生物大分子的氢键相互作用、大分子的复杂链运动、以及拉伸过程中多尺度结构与动力学的演化规律其对力学性能的影响，由此建立对高性能生物材料结构-性能关系的深入认识。在此基础上，通过多尺度的仿生分子设计来制备系列基于壳聚糖和多嵌段聚氨酯的高性能仿生高分子材料，推动我国生物基高分子与合成聚合物材料高性能化领域的基础与应用研究。

本项目围绕阐明生物大分子中分子间相互作用及多尺度结构与动力学、通过仿生分子设计制备高性能的生物基与合成高分子以实现传统合成聚合物的高性能化等方面开展了系列研究。通过异核相关等固体NMR技术揭示了纤维素/蚕丝共混物中生物大分子间相互作用，发展了动力学编辑的氘固体NMR新技术揭示了壳聚糖中微量水分子与生物大分子间复杂相互作用和微相分离结构对材料力学性能的影响，采用超高速质子双量子固体NMR技术实现了动态可逆交联高分子中互补多重氢键结构的精确检测，多核与多尺度固体NMR技术揭示了pH调控的高分子共混物中大分子间氢键及离子键相互作用及演化规律、阐明了嵌段聚氨酯中的拉伸硬化增强力学性质的微观起源和形状记忆聚合物结构-性能调控的微观机制。发展了系列多尺度仿生分子设计新方法构筑自愈合与可再加工的仿生高分子材料，制备了改性纤维素增强的嵌段聚氨酯、多重氢键与离子键协同构筑动态交联结构的高性能聚合物、以及多重刺激响应性的自修复和再加工聚氨酯和环氧树脂等新型高分子材料，实现了传统合成聚合物材料高性能化。针对高分子水凝胶发展了系列仿生分子设计策略，利用氢键、金属配位和疏水缔合等多重协同相互作用、以及自组装多级纳米结构构筑仿生高分子水凝胶，进而制备了系列基于全物理交联协同增强的多种智能水凝胶及其驱动器。