Polymers typically have very low thermal conductivity (~0.1-0.5W/mK). However, thermally conductive polymers have been pursued in recent years, this pursuit driven by important applications such as electronics cooling and energy storage. One approach to improve thermal conductivity has been to synthesize polymeric composites with high thermal conductivity nanoparticles, such as graphene and carbon nanotubes, which have thermal conductivities over 3000W/mK.
The overall increases in polymer thermal conductivity, however, have been very small (usually less than a factor of 3), mainly due to the large thermal resistance at the polymer-nanoparticle interfaces. Now, in a recent publication, and using molecular dynamics simulations, Luo and Lloyd have investigated the mechanism of heat transfer between polymer matrices and their filling particles (graphene and graphite).
Based on their study, they proposed three practical approaches to enhance the interfacial thermal conductance. These include the optimization of graphene size, increases in polymer density, and chemical modification of the graphene edges to promote strong covalent bonds between graphene and polymer molecules. Stronger interfacial interactions at the atomic level can enhance the heat transfer at the interface by almost an order of magnitude. These results offer valuable guidance to enhance thermal energy transport properties of polymeric nanocomposites.