Role of wetting and nanoscale roughness on thermal conductance at liquid-solid interface

Using non-equilibrium molecular dynamics simulations in which a temperature gradient is imposed, we determine the thermal resistance of a model liquid-solid interface with and without nanoscale roughness. Our simulations reveal that in both cases the key factor controlling interfacial thermal conductance is the strength of the bonding between liquid and solid atoms. In addition, we show that in the case of rough surfaces, the nanoscopic wetting-dewetting transition has a strong signature in the interfacial thermal conductance. Interestingly, the smooth and rough interfaces, despite distinct geometry, show quantitatively the same dependence of the interfacial conductance on the value of the interfacial adhesion.