Thermal transport across nanoparticle–fluid interfaces: the interplay of interfacial curvature and nanoparticle–fluid interactions

We investigate the general dependence of the thermal transport across nanoparticle–fluid interfaces using molecular dynamics computations. We show that the thermal conductance depends strongly both on the wetting characteristics of the nanoparticle–fluid interface and on the nanoparticle size. Strong nanoparticle–fluid interactions, leading to full wetting states in the host fluid, result in high thermal conductances and efficient interfacial transport of heat. Weak interactions result in partial drying or full drying states, and consistently low thermal conductances. The variation of the thermal conductance with particle size is found to depend on the fluid–nanoparticle interactions. Strong interactions coupled with large interfacial curvatures lead to optimum interfacial heat transport. This complex dependence can be modelled using an equation that includes the interfacial curvature as a parameter. In this way, we rationalise the existing experimental and computer simulation results and show that the thermal transport across nanoscale interfaces is determined by the correlations of both interfacial curvature and nanoparticle-fluid interactions.