Investigating interfacial thermal conductance of graphene/epoxy nanocomposites

The functionalization of graphene on interfacial thermal conductance (ITC) of graphene/epoxy nanocomposites was investigated using non-equilibrium molecular dynamics (NEMD) simulation. Moreover, the ITC for a single graphene and a few-layer graphene embedded within epoxy matrix were also examined. The influences of the surface modifications on the ITC were elaborated using the vibration density of state (VDOS) and the interaction energy. It was found that the graphene grafted with functional group demonstrates superior ITC than pristine graphene. The enhanced interaction energy between graphene and surrounding epoxy caused by the functionalization may be responsible for the improvement of ITC. In addition, the VDOS spectrums obtained from the functionalized graphene and epoxy matrix are more compatible and thus the functional group can effectively facilitate the energy transport with less phonon scattering in the interface. With regard to the few layer graphene, it was found that the ITC decreases when the layer number in few-layer graphene increases and eventually attains a certain value. Generally, increasing the number of graphene layer would increase the opportunity of the phonon scattering between each graphene layer as well as the outmost graphene layer and epoxy, which leads to the reduction of phonon transport intensity.