Lecture Theatre C, JCMB, King's Buildings
The interfacial thermal conductance at solid/liquid interfaces (G) has been studied extensively, specifically for its application in designing liquid-based cooling solutions for electronic devices. G plays a crucial role as the limiting factor in achieving optimal performance of such cooling devices. It has been long argued that G exhibits two distinct regimes: exponential dependence on wettability for weakly-bonded, or nonwetting liquids, and linear dependence for strongly-bonded, or wetting liquids. The transition between these regimes has been attributed to the relative importance of interfacial interactions, i.e., the switch occurs once the magnitude of solid/liquid interactions exceeds liquid/liquid interactions. In this work, we employ non-equilibrium molecular dynamics simulations to apply a temperature gradient at a Lennard-Jones solid/liquid interface and use this setup to determine the interfacial conductance for a wide range of surface wettabilities. By spectrally decomposing the heat flux within both the interfacial solid and liquid, we instead show for the first time that the regime transition occurs due to changes in the structural and thermal properties of the interfacial layers.
Abdullah El-Rifai is a 3rd year PhD student in the Institute for Multiscale Thermofluids in the University of Edinburgh. He obtained his MEng in mechanical engineering from the University of Edinburgh, where he used molecular dynamics (MD) to study the effect of solid-liquid wettability and heat-flux magnitude on the evaporative cooling capabilities of nanoporous membranes. In his PhD research, Abdullah employs MD simulations to investigate the influence of surface properties on interfacial thermal conductance at solid-liquid interfaces (G). His objective is to gain valuable insights into the mechanisms of energy transport between solids and liquids, with the goal of maximising G, consequently enhancing the performance of two-phase cooling devices.