Influence of Adsorbed Liquid Monolayer Ordering on the Kapitza Resistance at Solid/Liquid Interfaces

Applications ranging from small scale avionics control to AI computing platforms are ever more reliant on high density integrated chips prone to thermal runaway. Thermal extraction is now the limiting factor in information processing and so conventional air cooling is being displaced by microscale liquid cooling systems, which are more efficient due to the higher heat capacity of liquids. In this work, we use non-equilibrium MD simulations to examine thermal transport across solid/liquid (S/L) interfaces in quiescent fluids, as quantified by the Kapitza resistance. While previous studies have focused on interfacial behavior mediated by liquid density stratification, wettability and solid crystalline symmetry, we instead examine the influence of in-plane ordering within the first few liquid monolayers adsorbed at the solid surface. The characteristics of these proximal layers are tuned by varying the depth and repulsive distance characterizing the intermolecular potential. Our results, some intuitive and some not, yield general correlations between the Kapitza jump and measures of interfacial commensurability influenced by the structure and collective response of such monolayers.