单壁纳米碳管/聚酰亚胺复合材料的制备及导电特性

Preparation and Electrical Properties of SWNTs/PI Composites

采用熔融聚合法和反复机械拉伸法,制备出定向排列单壁纳米碳管(SWNTs)/聚酰亚胺(PI)复合材料。研究了纳米碳管在复合体中的排列和分散情况。讨论了填充纳米碳管的质量分数对复合材料导电性能的影响,发现SWNTs填充质量分数很少时,复合体系呈现渗流行为,表现出良好的导电性和各向异性,其电导率随着填充纳米碳管的质量分数增加,电导率增大,而且在其拉伸方向比其垂直方向显示出较高的电导率,沿着其拉伸方向的渗流阈值比其垂直方向要低,说明单壁碳纳米管在复合物材料中呈现出良好的排列和均匀分散。

The single-walled carbon nanotubes （SWNTs） filled nanocomposites SWNTs/polyimide （PI） with good uniformity, dispersion and alignment of SWNTs and with different SWNTs concentrations were produced by melt-mixing techniques and repeated stretching method. The problems of alignment and dispersion of SWNTs in the composite matrix and the electrical properties of composites were studied. The electrical properties of composites rise with the increase of SWNT concentration, composites show higher electrical conductivities along the stretched direction than perpendicular to it. The percolation threshold value along the stretching direction is lower than the value perpendicular to the SWNTs orientation. Anymore, the well dispersion and alignment of SWNTs in the SWNT/polymer composites present a low value of percolation threshold.