Shear thickening in Electrically Stabilized Colloidal Suspensions

TL;DR

This paper presents a new theoretical model for predicting the onset of shear thickening in electrostatically stabilized colloidal suspensions, accounting for total interaction potential and validated against experiments.

Contribution

It introduces an activation-based theory that considers both attraction and repulsion in total interaction potential for shear thickening onset prediction.

Findings

The model accurately predicts critical shear stress for shear thickening.

Comparison with experiments confirms the theory's applicability.

Accounts for constant potential and charge approaches in colloidal particles.

Abstract

A theory is presented for the onset of shear thickening in colloidal suspensions of particles, stabilized by an electrostatic repulsion. Based on an activation model a critical shear stress can be derived for the onset of shear thickening in dense suspensions for a constant potential and a constant charge approach of the spheres. Unlike previous models the total interaction potential is taken into account (sum of attraction and repulsion). The critical shear stress is related to the maximum of the total interaction potential scaled by the free volume per particle. A comparison with experimental investigations shows the applicability of the theory.