基于“反应-扩散”层层自组装原理构筑仿生多层结构海藻纤维及其应用探索

Seaweed polysaccharide is a kind of natural polyelectrolyte. Alginate fibers made from it have unique and outstanding performances such as intrinsic flame-retardant and biocompatibility. Biomimetic multilayer structural materials have been widely used in optics, biomedicine and other fields, and the preparation of multilayer structure alginate fibers is of great significance on the expansion of the application field. The purpose of this proposal is to utilize the polyelectrolyte properties of alginate to realize the fabrication of multilayer alginate fibers by spontaneous layer-by-layer assembly based on "reaction-diffusion" theory. We choose alginate and chitosan as a target for this proposal. The dynamics, thermodynamic and rheology properties of spinning solution and coagulation bath will be systematically studied in order to precisely control the competition and balancing between "solidification reaction" and "diffusion" during the spinning process of alginate fibers, to achieve the construction of multilayer structure alginate fibers. The formation mechanism of multilayer fibers will be investigated and will guide us to design and prepare biomimetic fiber materials with high performance. With the achievement of this proposal, the multilayer alginate fibers will have a wider application in adsorption separation, biomedicine and nano-materials. In addition, a new layer-by-layer self-assembly method will be developed which will facilitate the rapid and automatic fabrication of multilayer structural materials (fibers, membranes and capsules) in a large scale. All of the results will make a significant effect on both of theory and practical application for designing and preparation of biomimetic materials for marine polysaccharides.

海藻多糖是一种天然聚电解质高分子，由其制得的海藻纤维具有本质自阻燃、生物相容性等优异性能。仿生多层结构材料在光学、生物医学等领域具有广泛应用，制备多层结构海藻(SA)纤维对于其应用领域的扩展具有重要意义。本项目拟利用SA的聚电解质特性，基于“反应-扩散”理论，通过自发层层组装实现多层结构SA纤维的构筑。项目将以SA/壳聚糖体系为研究对象，系统研究纺丝原液及凝固浴的动力学、热力学和流变性质，精准调控SA纤维纺丝成型过程中“凝固反应”与“扩散”之间的竞争与平衡，实现多层结构SA纤维的构筑；揭示多层结构纤维的形成机制，指导高性能纤维新材料的仿生设计与制备。本项目的开展，有望拓展SA纤维在吸附分离、生物医学及纳米材料等领域中的应用，同时发展一种新的层层自组装方法，实现宏观意义上多层结构材料（纤维、薄膜及胶囊）的快速构筑，对于海洋多糖高分子仿生材料的设计与制备具有重要的科学理论价值和实际应用意义。

仿生多层结构材料由于在光学、生物医学、催化、能源等领域的广泛应用，一直是大家强烈关注的焦点。然而，迄今为止多层结构材料主要以薄膜和胶囊为主，多层结构纤维材料的制备仍是一个需要突破的难点。本项目成功利用海藻酸钠(SA)的聚电解质特性，基于“反应-扩散”理论，构建了多层结构SA纤维。通过系统研究纺丝原液的动力学、热力学和流变性质对SA纤维纺丝成型过程中“凝固反应”与“扩散反应”的影响，实现多层结构SA纤维的可控构筑，并揭示了多层结构纤维的形成机制，此外，本项目还利用了SA优异的金属络合与还原能力，将多层结构 SA 纤维作为模板制备了不同复杂形态和结构的纳米粒子；探索了多层结构SA纤维作为生物反应器的应用。该项目的研究成果对于海洋多糖高分子仿生材料的设计与制备具有重要的科学理论价值和实际应用意义。