Thermal conductivity of polymer composites with close-packed structure of nano and micro fillers

Thermal conductivity of polymer composites with nano and micro fillers has been investigated numerically and experimentally. The nano fillers used were multi-walled carbon nanotubes (MWNTs) and alumina nanoparticles, and the spherical alumina particles were selected as the micro fillers. A periodic unit cell with a random close-packed structure was created using a packing algorithm that treat the micro filler as spheres. Finite element analyses were also performed to predict the potential of nano fillers to enhance thermal conductivity of the composites and to analyze the effect of microstructure of micro fillers. Additionally, the polymer composites with nano and micro fillers were made and the thermal conductivity of the composites were measured. The results showed that the addition of MWNTs to the matrix lead to a large increase in thermal conductivity of the composites. The proposed thermal model predicted a thermal conductivity in good agreement with experiment.