Electrophoresis of colloidal dispersions in the low-salt regime

TL;DR

This paper investigates how the electrophoretic mobility of charged colloids varies with concentration in low-salt conditions, unifying experimental and simulation data into a single framework.

Contribution

It introduces a mapping using effective charge and screening parameters to unify diverse data sets on colloidal electrophoresis in low-salt regimes.

Findings

Identification of two distinct mobility regimes dependent on volume fraction.

Unified description of experimental and simulation data on colloidal electrophoresis.

Explanation of mobility behavior based on ionic double layer properties.

Abstract

We study the electrophoretic mobility of spherical charged colloids in a low-salt suspension as a function of the colloidal concentration. Using an effective particle charge and a reduced screening parameter, we map the data for systems with different particle charges and sizes, including numerical simulation data with full electrostatics and hydrodynamics and experimental data for latex dispersions, on a single master curve. We observe two different volume fraction-dependent regimes for the electrophoretic mobility that can be explained in terms of the static properties of the ionic double layer.