Counterions and water molecules in charged silicon nanochannels: the influence of surface charge discreteness

Abstract

In order to detect the effect of the surface charge discreteness on the properties at the solid-liquid interface, molecular dynamics simulation model taking consideration of the vibration of wall atoms was used to investigate the ion and water performance under different charge distributions. Through the comparison between simulation results and the theoretical prediction, it was found that, with the degree of discreteness increasing, much more counterions were attracted to the surface. These ions formed a denser accumulating layer which located much nearer to the surface and caused charge inversion. The ions in this layer were non-hydrated or partially hydrated. When a voltage was applied across the nanochannel, this dense accumulating layer did not move unlike the ions near uniformly charged surface. From the water density profiles obtained in nanochannels with different surface charge distributions, the influence of the surface charge discreteness on the water distributions could be neglected.

References in corpus (5)

• The Charge of Glass and Silica Surfaces
• Direct observation of charge inversion by multivalent ions as a universal electrostatic phenomenon
• Charge inversion in DNA-amphiphile complexes: Possible application to gene therapy
• Distribution of counterions and interaction between two similarly charged dielectric slabs: Roles of charge discreteness and dielectric inhomogeneity
• Long-range correlations of the surface charge density between electrical media with flat and spherical interfaces

Cited by in corpus (5)

• Ionic Behavior in Highly Concentrated Aqueous Solutions Nanoconfined between Discretely Charged Silicon Surfaces
• Dynamic Response of Ionic Current in Conical Nanopores
• Capacitance Performance of Sub-2-nm Graphene Nanochannels in Aqueous Electrolyte
• Modulation Mechanism of Ionic Transport through Short Nanopores by Charged Exterior Surfaces
• Ionic current rectification under concentration gradients and its application in evaluating surface charge properties of micropores