纳米粒子/海藻酸盐纺丝原液的黏弹调控机理及其结构-流变-性能关系

Alginate fiber is a kind of naturally environmentally friendly multifunctional fiber material. Spinning efficiency and fiber performance are the key obstacles to application expansion, and viscosity reduction by incorporation of nanoparticles is expected to simultaneously solve the two problems. In the project, three representative carbon-based nanoparticles (fullerenes (zero dimensional balls), carbon nanotubes (one-dimensional tubes) and graphene (two-dimensional sheets)) will be incorporated into sodium alginate (SA) concentrated solutions to obtain homogeneous spinning solutions. Influences of topology structure, filler content, aspect ratio and surface chemical properties of nanoparticles on the rheological behaviors of the spinning solutions will be systematically investigated. The theory analysis based two phase model and scaling model will be carried out to reveal the contributions of dispersion and aggregation of nanoparticles, SA chain relaxation and interfacial interaction to viscoelastic behaviors of suspensions, in order to clarify the viscoelastic regulation mechanism of spinning solutions. Nanoparticle/SA composite fibers will be fabricated by wet spinning, and microstructure-viscoelasticity-performance quantitative relationship will be established, which will guide optimization of fiber properties. And the results of viscoelastic regulation will be applied to broad the spinnable concentration range of SA solutions, in order to realize the objective of spinning with higher SA concentrated solutions. Implementation of the project will help to develop the theory research method of nanoparticle/polyelectrolyte complex system, enrich the contents of spinning processing rheology, and provide theoretical guidance and technical support for the achievement of high-performance and high-efficient processing of the new type of functional alginate composite fibers.

海藻纤维是一种纯天然、绿色环保的多功能纤维新材料，纺丝效率和纤维性能是制约其应用领域拓展的关键因素，纳米粒子降黏有望同时解决这两大问题。本项目拟在海藻酸钠（SA）浓溶液区引入富勒烯（零维球状）、碳纳米管（一维管状）和石墨烯（二维层状）三种代表性碳基纳米粒子，系统研究纳米粒子拓扑结构、含量、长径比和表面化学性质等因素对纺丝原液流变行为的影响规律，通过理论分析定量揭示粒子分散与聚集状态、SA分子弛豫特性和界面相互作用对黏弹行为的贡献，阐明黏弹调控机理；制备纳米粒子/SA复合纤维，建立微观结构-黏弹行为-材料性能的关联机制，进一步优化纤维性能；将黏弹调控的结果应用于SA纤维可纺浓度区间的扩展，实现SA高浓度纺丝。本项目的开展，将有助于发展纳米粒子/聚电解质复合体系黏弹行为的理论研究方法，丰富纤维加工流变学的研究内容，为实现新型功能性海藻纤维的高性能化和高效纺丝提供理论指导和技术支撑。

海藻纤维是一种纯天然、绿色环保的多功能纤维新材料，纺丝效率低下和纤维性能不足制约了其应用领域的拓展。本项目系统研究了富勒烯（C60）/海藻酸钠（SA）、不同表面化学结构碳纳米管（CNTs）/SA和不同还原程度石墨烯(RGO)/ SA三个悬浮液体系的流变行为，探明了纳米粒子含量、拓扑形态、聚合物浓度和表面化学结构等因素的影响规律；建立了时间-浓度叠加与两相模型相结合的理论研究方法，对纺丝原液的黏弹调控机理进行理论分析，结果表明“本体相”的受限弛豫行为对于静水力学区域的增强和损耗起到决定性作用，而“粒子相”的黏弹特性对于悬浮体系的非终端流动区的动态流变行为起到主导作用。通过湿法纺丝制备了纳米粒子/SA复合纤维，建立了结构-黏弹行为-材料性能的关联机制。将黏弹调控的结果应用于SA纤维可纺浓度区间的扩展，实现了SA高浓度纺丝，制备得到的复合海藻纤维，相比于传统纺丝溶液得到的纤维，力学性能得到显著提高。本项目的开展，将有助于发展纳米粒子/聚电解质复合体系黏弹行为的理论研究方法，丰富纤维加工流变学的研究内容，为实现新型功能性海藻纤维的高性能化和高效纺丝提供了理论指导和技术支撑。