具有导电纳米纤维网络结构的高分子复合材料的制备及其气敏行为研究

How to improve the dispersion of conductive nanofillers in polymer and obtain conductive polymer composite (CPC) possessing a low conductive percolation threshold and excellent comprehensive performance are the key issues in the theory study and practical application of CPC. In this project, conductive nanofiber network is constructed in the polymer matrix, in order to fabricate CPC with a low percolation threshold, and the prepared CPC is expected to have superior mechanical and electrical properties. The fabrication process is described below: Carbon nanotubes (CNTs) are first anchored onto the nylon 66/thermoplastic polyurethane(PA66/TPU) nanofiber with a core-shell structure under ultrasonication, followed by a hot press of the nanofiber composite at a proper temperature, which is lower than the melting point of PA66 while higher than the flowing temperature of TPU. CNTs are finally distributed on the PA66 nanofiber surface, forming a conductive network in the continuous TPU matrix. The construction of conductive network, the relation between the microstructure and the mechanical and electrical properties, the response of the resistivity to external field and the gas sensing performance of the conductive nanofiber based composite will be systematically investigated, based on which the mechanism of the conduction and gas sensing will be revealed. This project will open a new way to the fabrication of CPC with superior comprehensive properties, and provide both theoretic and experimental basis for developing this CPC to multifunctional materials.

如何改善导电粒子在高分子基体中的分散性、降低体系导电逾渗值及提高材料的综合性能是当前导电高分子复合材料理论研究与实际应用所亟需解决的关键问题。本项目拟通过在高分子基体中构建导电纳米纤维网络而制备具有低导电逾渗值和优异电学、机械性能的高分子复合材料，即：碳纳米管（CNTs）通过超声作用锚定到核壳PA66/TPU(尼龙66/热塑性聚氨酯)纤维中，经过热压成型（温度低于PA66熔点而高于TPU熔融流动温度）后，CNTs分布于PA66纳米纤维表面，在TPU连续相基体中形成导电网络。本课题将对导电纳米纤维网络的构建、结构与电学、机械性能之间的关系、复合材料电阻在外场作用下的响应规律、气敏行为进行系统研究,揭示材料的导电机理及气敏效应机理。本项目的重要意义在于为开发具有优异综合性能的导电高分子复合材料提供新的思路和方法，并为发展由此方法而制得的导电复合材料成为一种新型功能化材料提供理论基础和实验依据。

如何改善导电粒子在高分子基体中的分散性、降低体系导电逾渗值及提高材料的综合性能并拓展其功能化应用是当前导电高分子复合材料理论研究与实际应用所亟需解决的关键问题。本项目利用超声驱动碳纳米填料（碳纳米管、碳纳米纤维）在热塑性聚氨酯弹性体（TPU）的共混物纳米纤维表面组装，制备了具有导电纳米纤维网络结构的高分子复合材料，获得的纤维复合材料具有良好导电和力学性能、优异的气敏响应行为，揭示了材料的结构和性能之间的关系，探究了基于纤维网络结构的导电机理，阐明了其气敏效应机理。并通过对吸附于纤维表面的导电填料的进一步化学改性，实现纤维膜的超疏水，拓展了其在恶劣环境（如酸、碱、盐）条件下的应用。本项目为开发具有优异综合性能的导电高分子复合材料提供新的思路和方法，并为发展由此方法而制得的导电复合材料成为一种新型功能化材料提供理论基础和实验依据。项目执行过程中，在Journal of Materials Chemistry A、Chemical Engineering Journal、 Composites Science and Technology等本领域权威SCI期刊上发表学术论文11篇（均为第一或通讯作者），申请中国发明专利2项。协助培养博士生2名，培养硕士生2名，本科生2名。