具有各向异性结构的纳米复合水凝胶纤维宏量制备及其结构性能研究

Hydrogel fiber is a promising 1D material with particular spatiotemporal properties as fiber materials and functional properties as hydrogel, which are suitable for applications in biomaterial, signal transmission media and etc. However, fabricating hydrogel fiber based on monomer conveniently in large scale with uniform structure is always a difficulty. Here we develop a novel “polymerization with spinning” platform to achieve the large scale production of hydrogel fiber. Spinnability of nano-composite pre-gel solution, which is formed by mixing nanoparticles (clay or cellulose nanocrystal) with monomers homogeneously, will be analyzed based on the deeply research of rheology property and polymerization kinetics. Furthermore, the dynamic-crosslinking-spinning will be introduced to realize one-step fabrication of novel nano-composite hydrogel fibers with anisotropic structure continuously. In this project, we will systematically study the physical and chemical properties of fibers. In-situ online monitor the forming process of fibers will be achieved to reveal the revolution process of their condensed structures under complex external fields. In addition, the relationship between properties and condensed structures of fiber will be explored to provide new mechanisms and techniques for the construction of hydrogel fiber with integrated structure and functions.

水凝胶纤维材料兼具水凝胶功能特点及纤维结构优势，在生物材料、信号传输等领域有良好应用前景。然而以凝胶单体（大分子、齐聚物等）为纺丝原料，连续均匀地宏量构筑水凝胶纤维仍是难点。本项目针对水凝胶纤维制备过程中，纤维成形与交联网络构筑难以匹配的难题，拟以“纺丝过程中同步进行单体聚合”为研究思路，以纤维素纳米晶及纳米粘土为物理交联点，以可自由基聚合的凝胶单体为结构单元，系统分析纺丝流变学及聚合反应动力学对单体纺丝液可纺性的影响，建立并优化动态聚合纺丝新方法，实现凝胶化过程与纤维成形过程有机统一，连续制备具有各向异性结构的纳米复合水凝胶纤维，跟踪纤维成形过程，揭示纤维凝聚态结构及纳米粒子分布在复杂外场下演变规律，阐明纤维微结构与宏观性能的构效关系，为水凝胶纤维的宏量构筑提供新原理、新方法。

针对低分子量凝胶单体难以连续成纤的难题，围绕项目研究内容及年度计划，项目负责人组织实施开展研究，顺利完成项目计划。首先针对凝胶预聚液的可纺性，系统分析了其组分、温度、反应时间对纺丝液粘弹性的影响，创新性地提出了适合于低粘度牛顿流体的挤出方式，获得了连续的纺丝液细流；系统分析了成纤过程中的聚合反应动力学与体系粘弹性增长规律，获得了聚合反应动力学回归方程；揭示了纺丝液流变行为及聚合反应动力学协同作用对遥爪聚合物、单官能度聚合物、纳米复合凝胶预聚液可纺性的影响，建立了动态聚合纺丝新方法，实现了纳米复合水凝胶纤维连续成形。随后，阐明了纺丝过程中拉伸应力场诱导纤维各向异性结构演变的趋势，获得了强度媲美韧带与软骨的水凝胶纤维材料；进一步通过组分调控，实现光信号、电信号在纤维中的有效传导，构筑了基于凝胶纤维的水凝胶光纤及传感纤维材料，并探索了凝胶纤维材料在光医学、传感等领域的领用。在此基础上，通过纤维组分调控与宏观组装，构筑了宏观有序的高强各向异性凝胶纤维膜、纤维增强凝胶薄膜、抗冻耐挥发温敏凝胶膜、阻燃凝胶/织物复合材料等凝胶器件，为水凝胶材料的应用提供了新思路新方法。项目执行期间，共发表论文13篇（SCI论文12篇）；授权国家发明专利7项；培养博士后1人、博士1人、硕士2人、本科生1人；获省部级学生科创竞赛奖励1项；组织项目组参加国内外学术会议10余人次，项目负责人作口头报告4次。本项目研究成果具有一定的创新性和自主知识产权，在凝胶材料的新加工技术、多维度构建、新应用等方面具有基础创新性和应用示范性，有望推动水凝胶材料的技术进步和应用推广。