Enhanced water evaporation under spatially gradient electric Fields: A molecular dynamics study

Abstract

Solar steam generation can be affected by many external factors such as applied electric fields. The evaporation of water under uniform and time-varying electric fields have been widely investigated in both experimental and theoretical work. However, the effect of spatially gradient electric fields on water evaporation remains unknown. In this work, molecular dynamics simulations are conducted to investigate the mechanisms of enhanced water evaporation under spatially gradient electric fields. Results show that under spatially gradient electric fields, unbalanced electric forces acting on the two hydrogen atoms in a water molecule lead to a torque on the molecule with respect to its center of mass and thus accelerate the rotational motion. The accelerated rotational motion leads to a significant temperature rise of water and thus enhances the evaporation rate. Moreover, the performance of water evaporation is highly dependent on the type of applied spatially gradient electric fields. Fundamentally understanding the underlying mechanisms governing the effect of spatially gradient electric fields on the enhanced evaporation of water may be quite attractive to many applications such as plasmon-enhanced solar steam generation and electronics cooling.