固液界面电荷离散化对离子和水分布的影响

he surface charges developed at the solid-liquid interface are elementary charges in real world. They show discreteness on the solid surface, which is different from the mean field theory. In order to detect the effect of the surface charge discreteness on the properties at the interface, molecular dynamics simulation model taking consideration of the vibration of wall atoms was uesed to investigate the ion and water distributions under different charge distributions. Through the comparison between simulation results and theoretical prediction, it was found that with the degree of discreteness increasing, much more counterions are attracted to the surface. These ions form a denser accumulated layer which located much nearer to the surface. Then charge inversion appears which can not be explained by Poisson-Boltzmann equation. From the water density profiles obtained from different surface charge distributions, the influence of the surface charge discreteness on the water distributions can be neglected.