Revealing interfacial heating effects on water evaporation during surface distillation

Abstract

Interfacial heating is a widely adopted concept to effectively incur water evaporation in brines. Despite its wide application, namely for solar thermal and membrane distillations, there has been limited study on the criteria and efficacy of the approach. Herein, we propose a model system for evaluating surface heating effects on water evaporation using buoyant mesh Joule heaters. The buoyant mesh Joule heater was prepared by thermally oxidizing commercial Ni-Cr mesh, followed by coating with PTFE to enhance hydrophobicity. By applying voltages, the temperature of the heater can be controlled spontaneously up to 250 °C; the heater floats on water surfaces, accelerating the evaporation at the water/air interface. The setup's simplicity allows a systematic study of the interfacial heating method's depth effect, which was then further correlated with computational fluid dynamic simulations to investigate the fundamentals of accelerated water evaporation at water/air interfaces. © 2022 Elsevier B.V.