Role of Underlying Substrates on the Interfacial Thermal Transport in Supported Graphene Nanochannels: Implications of Thermal Translucency.

We study the role of underlying substrates on interfacial heat transfer within supported graphene nanochannels. Due to graphene's translucency, the underlying substrate, apart from its known hydrodynamic impact on fluid flow, also influences heat transport. We introduce the term "thermal translucency" to describe this phenomenon in the context of interfacial heat transfer. Our findings reveal that the Kapitza resistance, R K , is dependent on the specific underlying substrate. The specific underlying substrate alters the water-graphene interface potential landscape due to graphene's translucency, leading to a breakdown in the inverse relationship between interfacial water density peaks and R K values, typically observed at water-graphene and water-graphite interfaces. Remarkably, higher interfacial water density peaks correlate with more ordered energy patterns, not necessarily tied to more hydrophilic substrates as the literature commonly suggests for lower R K values. The insights provided have implications for controlling and tuning thermal transport and heat storage in nanofluidic devices.