A molecular dynamics study of effective thermal conductivity in nanocomposites

In this study, non-equilibrium molecular dynamics (NEMD) simulations are performed to determine the effective thermal conductivity of nanocomposites embedded with a variety of nanoparticles. The effects of orientation and arrangement of asymmetric nanoparticles, thermal property mismatch at the interface, interface density per unit volume of nanocomposite, and polydispersity of nanoparticles on the effective thermal conductivity of nanocomposites are investigated. Simulation results are compared with existing model predictions based on the effective medium approach. Results indicate that, with the same particle volume fraction, the nanocomposites that have a larger interfacial area perpendicular to heat flow or a larger interface density yield a smaller effective thermal conductivity. In addition, a larger mismatch at the interface between the host material and nanoparticle inclusions leads to a smaller effective thermal conductivity. Finally, it is found that the effective thermal conductivity of nanocomposites decreases with increasing polydispersity of embedded nanoparticles.