纳米石墨/聚乙烯复合材料电导特性模拟仿真

Simulation on Electrical Conductivity of Nano Graphite/PE Composites

为研究各因素对纳米石墨/聚乙烯复合材料电导特性的影响,在仿真计算的基础上绘制了具有不同微结构的纳米石墨/聚乙烯复合材料的电导率与外施电场强度关系曲线.通过改变纳米石墨的添加量、径厚比和取向程度设计了不同结构的纳米石墨/聚乙烯复合材料仿真模型,在其上下表面间施加直流电场后,利用COMSOL仿真软件基于有限元法模拟计算各模型内的电流密度分布,进而得到电流密度和电导率.研究结果表明:在纳米石墨的体积分数相同时,随着其径厚比和增加,在相同电场强度下复合材料的电导率显著增加;随纳米石墨沿外施电场方向取向程度的增大,复合材料的导电性明显提高.通过改变纳米石墨/聚乙烯复合材料的微结构可有效调控其电导特性.

Abstract： In order to investigate the electrical conductivity of nano graphite/polyethylene （PE） composites, the relationship curves between the external electrical filed strength and the electrical conductivity of nano graphite/ PE composites with different microstructures are generated based on numerical simulation. The simulation models of nano graphite/PE composites are designed through changing the contents, diameter to thickness ratio and orienta- tion degree of nano graphite. After a DC electrical field is applied between upper and lower surfaces of the compos- ites, the distribution of electrical current density is calculated based on the finite element method by using the COMSOL simulating software, and then the electrical current density and the electrical conductivity can be ob- tained. Research results indicate the electrical conductivity of the composites increases significantly with the in- crease of diameter to thickness ratio of nano graphite at the same nano graphite content and electrical field strength. As the orientation degree of nano graphite along external electrical field increases, the electrical conductivity of the composites obviously increases. It can therefore be concluded that change of the mierostructures of nano graphite/ PE composites is effective to control the electrical conductivity of the composites.