Rheology of Concentrated Colloidal Dispersions

Publication Reference: 
Author Last Name: 
Prof W B Russel
Report Type: 
ARR - Annual Report
Research Area: 
Wet Systems
Publication Year: 
Publication Month: 
United States


Suspensions of submicron particles in a liquid display a broad range of rheological behavior dependent on the size, concentration, and shape of the particles and the nature and magnitude of the interparticle potentials. The most dramatic phenomena occur when one of the interparticle forces dominates, e.g., strong van der Waals forces for flocculated carbon black dispersions, long range electrostatic repulsions for colloidal crystals, and the interactions between adsorbed layers in sterically stabilized suspensions near closest packing. Even with hard sphere interactions though, the rheology is significantly non- Newtonian at moderate concentrations.

The goal of our work is a quantitative theoretical understanding of the rheology of colloidal suspensions of industrial relevance. To this end we focus on well-defined systems of the type studied experimentally by Professor Mewis and seek to predict the observed viscosities and elastic moduli for the highly concentrated stable dispersions and the elasticity and plastic flow of the weakly flocculated carbon black dispersions.