Communication: Is a coarse-grained model for water sufficient to compute Kapitza conductance on non-polar surfaces?

Abstract

Coarse-grained models have increasingly been used in large-scale particle-based simulations. However, due to their lack of degrees of freedom, it is a priori unlikely that they straightforwardly represent thermal properties with the same accuracy as their atomistic counterparts. We take a first step in addressing the impact of liquid coarse-graining on interfacial heat conduction by showing that an atomistic and a coarse-grained model of water may yield similar values of the Kapitza conductance on few-layer graphene with interactions ranging from hydrophobic to mildly hydrophilic. By design the water models employed yield similar liquid layer structures on the graphene surfaces. Moreover, they share common vibration properties close to the surfaces and thus couple with the vibrations of graphene in a similar way. These common properties explain why they yield similar Kapitza conductance values despite their bulk thermal conductivity differing by more than a factor of two.

DosCalc: a parallelized tool to compute degree of freedom-separated density of states

“…We do not report an application for cross spectra in this paper. However, we believe them to be helpful in areas such as interfacial heat transfer, which is proportional to the velocity force cross-correlations [42] and connected to the magnitude of the DoS [20]. An extension of DosCalc to calculate the velocity force cross-correlations would be easy to implement.…”

“…[19] Changes in the spectra of all-atom and coarse-grained water on a graphite surface are connected to heat transfer through the phase boundary. [20] For the quantification of rotational dynamics, autocorrelation functions of the angular velocity vector or orientational vectors are typically used. The latter are related to the rotational correlation time, which can be determined e.g.…”

Effect of Defects on the Interfacial Thermal Conductance between n-Heneicosane in Solid and Liquid Phases and a Graphene Monolayer

“…Experimental investigation of molecular level heat transfer characteristics across the interfaces is challenging. Molecular dynamics (MD) simulation is one of the computer simulation techniques that is well suited to study the mechanism of nanoscale interfacial heat transfer as well as for evaluating the magnitude of thermal conductance. − In our recent article, we observed that the thermal conductance at the interface between edge-on ideal crystal and single-layer graphene is two times higher than that for the interface between liquid heneicosane and graphene.…”

Solid-like Behaviors Govern Evaporative Transport in Adsorbed Water Nanofilms

“…While there have been extensive studies to investigate thermal resistances at different types of interfaces by employing experimental analysis, analytical modeling, and numerical simulations, , traditional experimental approaches become impractical at nanometer scales. Instead, molecular dynamics (MD) simulations can provide a sufficient means to investigate nanoscale interfacial physics from an atomistic perspective. , The use of MD simulations enables the detailed calculations of thermophysical characteristics across individual phases and interfaces. − The solid–liquid interfaces are reported with the focus on the surface morphological information, − chemistry and roughness, nanofilm thickness, molecule packing levels, or their wettability, − while the solid–liquid interfaces are influenced by phonon scattering mismatches. − It has been reported that thermal resistances at solid–liquid interfaces for thin liquid films in the range of nanometers are comparable to those at solid–solid interfaces. , The majority of the previous studies has merely focused on the thermal transport between a solid and liquid without phase change. ,− …”

“…47−50 It has been reported that thermal resistances at solid−liquid interfaces for thin liquid films in the range of nanometers are comparable to those at solid−solid interfaces. 51,52 The majority of the previous studies has merely focused on the thermal transport between a solid and liquid without phase change. 49,53−55 The solid−liquid interfacial resistances have drawn attention during phase change phenomena.…”