气流气泡纺制备纳米纤维及其机理研究

Electrospinning is widely used for nanofiber fabrication, however, it is difficult to produce nanofiber assembly similar to that of the dragline silk, additionally its spinnability mainly depends upon the properties of the spun solution or melt including the viscosity and dielectricity, furthermore electrostatic hazards are the cause of fires and explosion in industrial applications. It is, therefore, very necessary that the electrostatic force is replaced during the nanofiber fabrication. The blown bubble-spinning technology is to fabricate nanofibers and yarns by using the blowing air to overcome the surface tension of a polymer/melt bubble.The project gives a systemtical analysis of effects of various parameters (such as blowing air, temperture, bubble size) on fiber size and mechanical propoerty of yarns , which is size-depentent. Using the nano-effect of nanofibers, the mechanical property of yarns can be improved greatly. Additionally a mechanics model is established for the spinning process, and numerical simulation and experimental verification are carried out to optimally design a new device of blown bubble-spinning to improve spinability and increase producity.

静电纺是产生纳米纤维的主要方法之一，但很难用一步成纱法制作像蜘蛛丝一样的纳米纤维集合体， 并且其可纺性与溶液的性质（粘性系数和介电系数）有关。另外在工业化生产中，静电会引起火灾与爆炸, 因此有必要开发无静电的纺丝新方法。气流气泡纺是用气流作为动力，克服聚合物溶液或熔体气泡的表面张力而实现纺丝和纺纱过程。本项目将研究各种工艺参数（如气流场、温度、湿度和气泡直径等）对纳米纤维直径的影响，以及纳米纤维直径对纳米复合纱力学性能的影响，充分利用纳米效应，大幅增强纳米复合纱的力学性能。同时对纺丝过程进行力学和数值分析，并进行实验验证，优化各工艺参数，开发具有自主知识产权的新一代气泡纺丝装置，提高聚合物溶液或熔体的可纺性和产品产量，为工业化生产做好前期准备。

本项目系统研究了气泡纺的各个阶段的关键力学问题，研究了外力作用下气泡生产、气泡相互作用、气泡变形和气泡破裂的机理，从实验和理论分析上确认了气泡寿命和气泡的生产频率是影响纳米纤维产量的重要因素，气泡大小和气泡变形过程是影响产品形貌和性能的关键参数。本项目的研究成果有望实现纳米纤维的工业化生产。