Molecular Dynamics Simulation Of Dewetting Of Water In Nanoscavities Induced By Electric Field

The study of the physicochemical properties of water in the nanocavities is of great significance in the fields of nanomaterials dewetting,oil recovery,soil remediation,energy conversion,storage applications and protein folding.Over the past decades,scientists have been studying the dry-wet transition of water in nano-pores and the effects of various factors on nanolimited water,such as electric field,hydrophobicity,lateral pressure,interface size,etc.Because the positive and negative charge center of the water molecule does not coincide,the water molecule has polarity,and the hydrogen bond network of the molecule under the action of electric field will be destroyed and recombined.Therefore,electric field may be a powerful way to dry nanomaterials.In this paper,the effect of electric field on the properties of water in nanocavities at ambient temperature is studied by molecular dynamics simulation based on classical Newtonian mechanical method.We remove water molecules confined to two parallel graphene plates(one of which has a certain size of pores)into the vacuum chamber by increasing the temperature and applying an electric field.At ambient temperature,the rate of dewetting induced by electric field is very large.Whereas,it is a very low rate of dewetting induced by high temperature(423 K)due to the strong interaction of the hydrogen-bonding networks of water droplets in nanocavities.Simulation results show that when the temperature is 423 k,the number of water molecules escaping into the vacuum chamber is very small.But under the action of electric field of certain intensity,the escape rate is large,and the number of water molecules escaping to vacuum chamber is many.In addition,the electric filed induced water column formation has been found in vacuum chamber(extension of the water column in the direction of the electric field).When the electric field is turned off,the water column will transform into a water droplet.Importantly,the results demonstrate that the rate of electric field-induced dewetting increases with growth of the electric field.That is to say,compared with the traditional thermal drying method,the electro-induced drying method is very efficient.Overall,our results suggest that electric field may have a great potential application for nanomaterial dewetting.