Controlling the interfacial and bulk concentrations of spontaneously charged colloids in non-polar media

TL;DR

This paper develops a modified mean field model to analyze the concentrations of spontaneously charged colloids near interfaces and in bulk non-polar media, providing insights into double layer widths and steady-state conditions.

Contribution

It introduces a mean field model incorporating finite size effects and disproportionation kinetics for better understanding of colloid distributions in non-polar media.

Findings

Evaluates the width of condensed double layers near electrodes.

Estimates minimum initial colloid concentrations for electroneutrality.

Provides insights into quasi-steady state currents in inverse micellar media.

Abstract

Stabilization and dispersion of electrical charge by colloids in non-polar media, such as nano-particles or inverse micelles, is significant for a variety of chemical and technological applications, ranging from drug delivery to e-ink. Many applications require knowledge about concentrations near the solid|liquid interface and the bulk, particularly in media where colloids exhibit spontaneous charging properties. By modification of the mean field equations to include the finite size effects that are typical in concentrated electrolytes along with disproportionation kinetics, and by considering high potentials, it is possible to evaluate the width of the condensed double layers near planar electrodes and the bulk concentrations of colloids at steady state. These quantities also provide an estimate of the minimum initial colloid concentration that is required to support electroneutrality in the dispersion bulk, and thus provide insights into the quasi-steady state currents that have been observed in inverse micellar media.