Determination of the zeta potential for highly charged colloidal suspensions

TL;DR

This paper uses a hybrid mesoscopic model to compute the zeta potential of highly charged colloidal particles, showing its consistency in different conditions and analyzing factors affecting its measurement.

Contribution

It introduces a hybrid mesoscopic approach to accurately determine zeta potential in highly charged colloids, including effects of counterion concentration and lattice resolution.

Findings

Zeta potential during electrophoresis matches equilibrium values.

Counterion concentration significantly influences zeta potential.

Lattice resolution impacts the accuracy of zeta potential calculations.

Abstract

We compute the electrostatic potential at the surface, or zeta potential $\zeta$, of a charged particle embedded in a colloidal suspension using a hybrid mesoscopic model. We show that for weakly perturbing electric fields, the value of $\zeta$ obtained at steady state during electrophoresis is statistically indistinguishable from $\zeta$ in thermodynamic equilibrium. We quantify the effect of counterions concentration on $\zeta$. We also evaluate the relevance of the lattice resolution for the calculation of $\zeta$ and discuss how to identify the effective electrostatic radius.