Modeling electrical conductivities of nanocomposites with aligned carbon nanotubes

Abstract

We have developed an improved three-dimensional (3D) percolation model toinvestigate the effect of the alignment of carbon nanotubes (CNTs) on the electricalconductivity of nanocomposites. In this model, both intrinsic and contact resistancesare considered, and a new method of resistor network recognition that employsperiodically connective paths is developed. This method leads to a reduction in the sizeeffect of the representative cuboid in our Monte Carlo simulations. With this newtechnique, we were able to effectively analyze the effects of the CNT alignmentupon the electrical conductivity of nanocomposites. Our model predicted that thepeak value of the conductivity occurs for partially aligned rather than perfectlyaligned CNTs. It has also identified the value of the peak and the correspondingalignment for different volume fractions of CNTs. Our model works well for bothmulti-wall CNTs (MWCNTs) and single-wall CNTs (SWCNTs), and the numericalresults show a quantitative agreement with existing experimental observations.