Rheological characterizations of dispersions of clay particles in viscoelastic polymer solutions

Abstract

International audienceIn this work, we consider model fluids which are dispersions of clay particles in aqueous solutions of carboxymethyl cellulose. Their rheological properties are measured in both steady and oscillatory shear flows. We present the experimental results obtained for different polymer concentrations and for three different molecular weights of the polymer. The clay is a bentonite sample and the particle concentration is fixed to a value of 5 %. The mechanical properties of these materials is the result of a competition between different mechanisms: association-dissociation of aggregates of particles, adsorption of polymer on the particles and desorption of solvent molecules from the particles, bridging of the particles by long polymer chains