Oscillations in incident electric field enhances interfacial water evaporation†

Abstract

The observed superthermal evaporation rate of water from porous hydrogels has been attributed to different reasons, such as the formation of intermediate water state with reduced latent heat, and the emission of water clusters cleaved off by photons. However, it remains unclear how the electromagnetic field interacts with the liquid–vapor interface and enhances evaporation at the molecular level. Here, we employed non-equilibrium molecular dynamics simulations to investigate interfacial evaporation from pure water and polyvinyl alcohol hydrogels. Our results show that the evaporation rate remains consistent for a given interfacial heat input, regardless of hydrogel presence, suggesting that forming different water states alone does not enhance evaporation. When an alternating electric field is applied, we observed enhanced evaporation due to the cleavage of water molecules and clusters formed in the interface region, particularly when water was confined within hydrogels.