Thermal conductance of the water-gold interface: The impact of the treatment of surface polarization in non-equilibrium molecular simulations

JD Olarte-Plata and F Bresme, JOURNAL OF CHEMICAL PHYSICS, 156, 204701 (2022).

DOI: 10.1063/5.0090983

Interfacial thermal conductance (ITC) quantifies heat transport across material-fluid interfaces. It is a property of crucial importance to study heat transfer processes at both macro- and nanoscales. Therefore, it is essential to accurately model the specific interactions between solids and liquids. Here, we investigate the thermal conductance of gold-water interfaces using polarizable and non-polarizable models. Both models have been fitted to reproduce the interfacial tension of the gold-water interface, but they predict significantly different ITCs. We demonstrate that the treatment of polarization using Drude-like models, widely employed in molecular simulations, leads to a coupling of the solid and liquid vibrational modes that give rise to a significant overestimation of the ITCs. We analyze the dependence of the vibrational coupling with the mass of the Drude particle and propose a solution to the artificial enhancement of the ITC, preserving at the same time the polarization response of the solid. Based on our calculations, we estimate ITCs of 200 MW/(m(2) K) for the water-gold interface. This magnitude is comparable to that reported recently for gold-water interfaces 279 +/- 16 MW/(m(2) K) using atomic fluctuating charges to account for the polarization contribution. (c) 2022 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license(http://creativecommons.org/licenses/by/4.0/).

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