Effects Of Surface Polar And Electric Field On Properties Of Nanoscale Solid-Liquid Interface

The solid-liquid interface properties at the nanoscale play a pivotal role in both industrial production and daily life.The nanoscale interface liquid,which is closed to a solid surface,has many unique properties compared to bulk liquids.In this paper,the following contents are studied by molecular dynamics simulation:1.Effects of surface polarity on nanoscale interfacial water aggregation propertiesThe properties of a nanosized water aggregation on solid surfaces with different polar atom densities（D）was investigated using molecular dynamics simulations.The results show that the evaporation rate of the nanosized water aggregation changes non-monotonically with the increase in D.The simulation results also confirm that the evaporation rate of the nano-sized water aggregation changes non-monotonically with the increase in partial charge.The minimum evaporation rate of the water aggregation,which was only 0.6%of that on the nonpolar solid surface(D=0 No.nm^-2),was obtained when the solid surface had a polar atom ratio of 66.7%(25.8 No.nm^-2).Our findings should be helpful in designing artificial surfaces with moisturizing functions.2.Effects of surface polarity on nanoscale interfacial ethanol aqueous solutions proper-tiesThe properties of a nanoscale interfacial ethanol aqueous solution on a solid surface were studied by molecular dynamics simulation.The results show that the ratio of ethanol to water molecules in the interface ethanol aqueous solution and the bulk ethanol aqueous solution is very different.When the polarity is introduced on the solid surface,the ratio of the two in the interfacial ethanol aqueous solution is further affected by the change in surface polarity.In addition,it is not that the denser the polar atoms on the solid surface,the greater the effect of surface polarity on the ratio of the two in the interface ethanol aqueous solution.The spatial arrangement of the larger proportion of molecules in the interfacial ethanol solution is more orderly,and more hydrogen bonds are generated between other molecules in the solution,which further increases the proportion of molecules in the ethanol aqueous solution at the interface.This study can provide some help in understanding the microstructure of an interfacial ethanol aqueous solution.3.Effects of electric field on nanoscale interfacial water properties in nanoslitsA nanoslit structure model was designed by introducing two parallel nanoscale graphene sheets into the bulk water environment.The changes of interfacial water properties in the nanoslit structure were studied by molecular dynamics simulation when an external elec-tric field perpendicular/parallel to the graphene sheet was applied.The results showed that the number of water molecules in the nanoslit structure remained constant throughout the simulation when the two graphene sheets formed the nanoslit structure had the appropriate size and spacing,that is,the nanoslit structure had a dry/wet self-locking property.When the external electric field is applied,the number of water molecules in the nanoslit struc-ture changes significantly,that is,from wet→dry/dry→wet state changes.Using these properties of the above nanoslits,a non-volatile storage device can be designed.