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

Abstract

The interfacial thermal conductance (ITC) quantifies the heat transport across material-fluid interfaces. It is a property of crucial importance to study heat transfer processes both at 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's vibrational modes that gives 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/(m2 K) for the water-gold interface. This magnitude is comparable to that reported recently for gold-water interfaces (279+-16 MW/(m2 K)), using atomic fluctuating charges to account for the polarization contribution.

Impact of the Interfacial Thermal Conductance on the Thermoplasmonic Response of Metal/Polymer Hybrid Nanoparticles under Nanosecond Pulsed Illumination

“…We used these parameters for our analysis along with an ITC of G K = 150 MW/(K m 2 ), as reported in ref . Recently, the ITC of gold–water interface was computed using molecular dynamics simulations and polarizable metallic surfaces, predicting values of G K = 200 MW/(K m 2 ) for gold temperatures of the order of 60 °C. We also performed calculations with this ITC.…”

“…Transient thermal response of a 20 nm radius ( R ) gold sphere illuminated by a temporal Gaussian pulse with F = 38 J/m 2 , τ = 1 ns, and t 0 = 2 ns. Time evolution of the temperature profiles along the x axis (radial distance) for (a) gold–water ITC of G K = 150 .25em normalM normalW normalm 2 .25em normalK and gold and water thermal conductivities independent of temperature ( k normalw = 0.6 .25em normalW normalm normalK .25em , .25em k normalA normalu = 307.2 .25em normalW normalm .25em normalK ), (b) G K = 150 .25em normalM normalW normalm 2 .25em normalK and temperature dependent thermal conductivities (see Figure S2 in the SI), and (c) G K = 200 .25em normalM normalW normalm 2 .25em normalK taken from ref and temperature dependent thermal conductivities. The red curve represents the time evolution of the temperature inside the gold, and the yellow one is the interfacial temperature corresponding to the temperature of the solvent at a radial distance of 0.1 nm from the gold surface ( T Au/w ).…”

“…Figure a shows the temperature profiles as a function of time. For our calculations we considered the gold/PMMA and PMMA/water ITCs, 59 and 50 normalM normalW normalm 2 .25em normalK , , respectively, while the value for gold/water ITC was 200 normalM normalW normalm 2 .25em normalK . The maximum temperature is reached at t = 2.4 ns, followed by a rapid temperature relaxation over time.…”

“…For our calculations we considered the gold/PMMA and PMMA/water ITCs, 59 and 50 MW m K 2 , 43,44 respectively, while the value for gold/water ITC was 200 MW m K 2 . 21 The maximum temperature is reached at t = 2.4 ns, followed by a rapid temperature relaxation over time. Also, notice that the gold nanocap is heated first upon illumination, an event that is followed by internal heat transfer to the polymer core and external heat transfer to the solvent.…”

Thermal Conductivity of a Fluid-Filled Nanoporous Material: Underlying Molecular Mechanisms and the Rattle Effect

“…At the molecular scale, many works have focused on Kapitza effects, which characterize heat transfers and temperature jumps at fluid/solid − or fluid/soft matter , interfaces. In this context, molecular simulation is a powerful tool as it allows probing nanoscale effects such as the impact of surface patterning, curvature/interactions, and polarization on thermal interfacial resistance. Attempts to upscale results from molecular methods have been reported using analytical , or finite element/discrete methods .…”