RHEOLOGICAL PROPERTIES OF STRUCTURED FLUIDS

The kinetic theory proposed by Soong and Liu for describing the rheolo gical properties of structured fluids has been extended to predict she ar-thinning, shear-thickening, thixotropy, and antithixotropy in diffe rent ranges of shear rates. Viscoelastic properties, as given by the G ordon-Schowalter Maxwell model, with a non-constant modulus, have also been considered. The theoretical predictions are compared with the pr edictions of a model used by Ait-Kadi, et al. (1988), for a hydrolyzed polyacrylamide solution containing 20 g/1 of NaCl. The predictions an d experimental data for the viscosity and primary normal stress coeffi cient are in reasonably good agreement. The stress growth functions ha ve also been calculated and have been found to be consistent with expe rimental observations.