Ash’s paper, “Spectral analysis of thermal boundary conductance across solid/classical liquid interfaces: a molecular dynamics study,” has been published in Applied Physics Letters (Appl. Phys. Lett. 105, 033106 (2014)). In this work, we use molecular dynamics simulations to show that the adhesion between a solid and a liquid (macroscopically referred to as the degree of wetting) has a pronounced spectral effect on phonon transmission, drastically affecting the transmission of low frequency modes across solid liquid interfaces. This quantifies, from an atomistic perspective, how wetting affects thermal boundary conductance across solid/liquid interfaces. Congrats Ash!!!
Abstract
We investigate the fundamental mechanisms driving thermal transport across solid/classical-liquid interfaces via non-equilibrium molecular dynamics simulations. We show that the increase in thermal boundary conductance across strongly bonded solid/liquid interfaces compared to weakly bonded interfaces is due to increased coupling of low-frequency modes when the solidis better wetted by the liquid. Local phonon density of states and spectral temperature calculations confirm this finding. Specifically, we show that highly wetted solids couple low frequency phonon energies more efficiently, where the interface of a poorly wetted solid acts like free surfaces. The spectral temperature calculations provide further evidence of low frequency phonon mode coupling under non equilibrium conditions. These results quantitatively explain the influence of wetting on thermal boundary conductance across solid/liquid interfaces.
We appreciate support from the Office of Naval Research Young Investigator Program (Grant No. N00014-13-4-0528).
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