Enhanced structural correlations accelerate diffusion in charge-stabilized colloidal suspensions

TL;DR

This paper demonstrates that hydrodynamic interactions significantly influence particle diffusion in charge-stabilized colloids, with experimental results confirming theoretical predictions despite small effects.

Contribution

It provides the first experimental validation of theoretical models predicting hydrodynamic effects on diffusion in charge-stabilized colloids.

Findings

Hydrodynamic interactions alter short-time self-diffusion coefficients.

Experimental data agrees with theoretical predictions.

Effects are small but detectable with advanced techniques.

Abstract

Theoretical calculations for colloidal charge-stabilized and hard sphere suspensions show that hydrodynamic interactions yield a qualitatively different particle concentration dependence of the short-time self-diffusion coefficient. The effect, however, is numerically small and hardly accessible by conventional light scattering experiments. Applying multiple-scattering decorrelation equipment and a careful data analysis we show that the theoretical prediction for charged particles is in agreement with our experimental results from aqueous polystyrene latex suspensions.