碳纤维/芳纶纤维纸基复合材料电导率逾渗阈值的研究

Study on the Conductivity Percolation Threshold of Carbon Fiber / Aramid Fiber Paper-based Composites

关键词:  碳纤维  导电纸基复合材料  数值模拟  逾渗阈值

Key Words:carbon fiber  conductive paper-based composite materials  numerical simulation  percolation threshold

摘要:本研究利用碳纤维和芳纶纤维通过湿法造纸成形技术制备导电纸基复合材料（CPCMs），探讨了碳纤维含量、长度与CPCMs导电逾渗阈值的相关性；并通过数值仿真软件Geodict模拟了CPCMs的结构，用于计算其电性能及导电逾渗阈值。结果表明，3 mm碳纤维制备的CPCMs表面电导率逾渗阈值为2.25%，体积电导率逾渗阈值为2.86%；不同长度碳纤维制备的CPCMs具有不同的电导率逾渗阈值，碳纤维长度2~9 mm范围内，随着碳纤维长度的增加，CPCMs的电导率逾渗阈值逐渐下降。模拟计算结果表明，当模拟区域大小为1 mm²时，2 mm长碳纤维的CPCMs模型逾渗阈值模拟结果与实验结果有较好的对应性。

Abstract:Percolation threshold is one of the important parameters to characterize the conductive properties of conductive composites. Carbon fiber (CF) and Aramid fiber (AF) were used to prepare conductive paper-based composite materials (CPCMs). The effects of CF contents and lengths on the percolation threshold of CPCMs were discussed. The structures of CPCMs were simulated by numerical simulation software Geodict, which could be used to predict the electrical property and the conductive percolation threshold of CPCMs. The experimental results showed that the CPCMs prepared with 3 mm CF displayed the surface and volume conductivity percolation threshold were 2.25% and 2.86% respectively. The CPCMs fabricated by different lengths of carbon fiber had different electrical conductivity. The CPCMs percolation threshold gradually decreased as CF length increased in the range of 2 to 9 mm. The thresholds of CPCMs with different lengths of carbon fiber were calculated by simulation. When the simulation area was 1mm², the simulation value of the sample prepared with 2 mm CF was close to the experimental value.