Determination of interfacial thermal resistance at the nanoscale

Using molecular dynamics simulations and model graphene layers in an organic matrix we demonstrate that interfacial thermal resistance determined via thermal relaxation method is up to an order of magnitude larger than that determined from direct simulation method of heat transfer across the matrix-graphene-matrix interface. We provide an explanation of this difference based on the spectral analysis of the frequency-dependent vibrational temperature. The importance of our finding lies in the fact that the relaxation method mimics experimental laser-based pump-probe measurements of the interfacial thermal resistance, while the direct simulation method provides information relevant to predicting and understanding thermal conductivity of nanocomposites.