Effect of percolation on thermal transport in nanotube composites

The effective thermal conductivity of two-dimensional (2D) nanocomposites composed of carbon nanotubes (CNTs) dispersed in a host substrate is simulated to quantify the role of tube percolation on the thermal transport. The model is in excellent agreement with a 2D effective medium theory for low tube densities, but departs significantly from it when tube-tube interaction becomes significant. It is found that percolation effects may play a role for tube-tube and tube-substrate thermal resistance parameters typical of CNT composites. They are quantified in terms of a conductivity exponent for a range of governing parameters.