Interfacial layer effects on surface capacitances and electro-osmosis in electrolytes

Abstract

Many properties of the interfacial layer of water at surfaces differ significantly from those of bulk water. The consequences are most significant for the doublelayer capacitance and the electrokinetic properties. We model the interfacial hydration layer by a modified dielectric constant and a modified local viscosity over a single interfacial width. Analytic expressions in the low-charge Debye-Hückel approximation are derived and shown to describe experimental surface capacitance and electro-osmotic data in a unified framework.