Effects of Contact Behavior and Electric Field on Electrohydrodynamics of Nanodroplets

We systematically investigated the coupling effects of the water-surface interactions and electric field on electrohydrodynamics behaviors of nanodroplets based on molecular dynamics simulations. The coupling effects have been not addressed in previous works. Our results indicate that the combination of the water–surface interactions with the electric field influences significantly the contact characteristics of droplets on the surface and their shape evolution. The droplets negligibly deform at weak electric field. The enhancement of the water-surface interactions remarkably increases the critical electric field to induce large deformation of droplets. The deflection of dipole orientation of the interfacial water molecules owing to the electric field is suppressed by improving the water-surface interactions. The average number of hydrogen bonds per interfacial water molecule increases with the surface-water interactions at fixed electric field. Additionally, the critical field strength inducing the decrease of the number of hydrogen bonds also increases due to the enhancement of the water–surface interactions. It can be related to the proportion of water molecules close to three phase boundary to the number of interfacial water molecules and the water density in the interfacial region.