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 double-layer 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.