Thermal rectification induced by Wenzel–Cassie wetting state transition on nano-structured solid–liquid interfaces

Abstract

Thermal rectification refers to the phenomenon by which the magnitude of the heat flux in one direction is much larger than that in the opposite direction. In this study, we propose to implement the thermal rectification phenomenon in an asymmetric solid-liquid-solid sandwiched system with a nano-structured interface. By using the non-equilibrium molecular dynamics simulations, the thermal transport through the solid-liquid-solid system is examined, and the thermal rectification phenomenon can be observed. It is revealed that the thermal rectification effect can be attributed to the significant difference in the interfacial thermal resistance between Cassie and Wenzel states when reversing the temperature bias. In addition, the effect of the liquid density, solid-liquid bonding strength and nanostructure size on the thermal rectification is also examined. The findings in this paper provide a new way for the design of certain thermal devices.

Thermal control devices and thermal circuits

“…Li et al [21] numerically analysed the thermal diode based on the change in interfacial thermal resistance caused by the temperature-dependent transition between Cassie and Wenzel wetting states. For a solid-liquid interface with nanostructured grooves on the surface, its wettability state can be in the Cassie state (no liquid molecules enter the nanogrooves) and in the Wenzel state (all grooves are filled with liquid molecules).…”