Unraveling the Regimes of Interfacial Thermal Conductance at a Solid/Liquid Interface

The interfacial thermal conductance at a solid/liquid interface (G) exhibits an exponential-to-linear cross-over with increasing solid/liquid interaction strength, previously attributed to the relative strength of solid/liquid to liquid/liquid interactions. Instead, using a simple Lennard-Jones setup, our molecular simulations reveal that this cross-over occurs due to the onset of solidification in the interfacial liquid at high solid/liquid interaction strengths. This solidification subsequently influences interfacial energy transport, leading to the cross-over in G. We use the overlap between the spectrally decomposed heat fluxes of the interfacial solid and liquid to pinpoint when “solid-like energy transport” within the interfacial liquid emerges. We also propose a novel decomposition of G into: i) the conductance right at the solid/liquid interface and ii) the conductance of the nanoscale interfacial liquid region. We demonstrate that the rise of solid-like energy transport within the interfacial liquid influences the relative magnitude of these conductances, which in turn dictates when the cross-over occurs. Our results can aid engineers in optimizing G at realistic interfaces, critical to designing effective cooling solutions for electronics among other applications. This data set contains the MD simulation files and post-processing codes to reproduce our results. The dataset is related to the publication by Abdullah El-Rifai, Sree Hari Perumanath Dharmapalan, Matthew K. Borg and Rohit Pillai (2024), "Unraveling the Regimes of Interfacial Thermal Conductance at a Solid/Liquid Interface", Journal of Physical Chemistry C, https://doi.org/10.1021/acs.jpcc.4c00536