Dielectric modulation of ion transport near interfaces

TL;DR

This paper reveals how dielectric mismatch at interfaces can significantly alter ion transport in nanodevices, showing that surface effects influence ionic mobility through polarization forces and ionic atmosphere modifications.

Contribution

It introduces a novel mechanism where dielectric mismatch affects ion mobility via polarization forces, expanding understanding of surface effects in nanodevice ion transport.

Findings

Dielectric mismatch can enhance or reduce ionic mobility.

Polarization forces influence ionic atmosphere near interfaces.

Salt concentration and electrostatic coupling modulate the effect.

Abstract

Ion mobility and ionic conductance in nanodevices are known to deviate from bulk behavior, a phenomenon often attributed to surface effects. We demonstrate that dielectric mismatch between the electrolyte and the surface can qualitatively alter ionic transport in a counterintuitive manner. Instead of following the polarization-induced modulation of the concentration profile, mobility is enhanced or reduced by changes in the ionic atmosphere near the interface and affected by a polarization force parallel to the surface. In addition to revealing this mechanism, we explore the effect of salt concentration and electrostatic coupling.