VISCOSITY OF CONCENTRATED DISPERSIONS OF SPHERICAL PARTICLES IN THE FRAMEWORK OF A STRUCTURAL MODEL

Viscosity curves obtained for four types of colloidal dispersion of spherical particles with different degrees of dispersion and composition of the dispersion medium are considered within the framework of a structural rheological model. The analysis of rheological curves using three types of coordinate axes is presented. The approximation of the structural rheological model by rheological equations is carried out at separate intervals of shear rates. It is shown that in the region of high shear rates, experimental data are successfully described by a generalized flow equation (aggregates are destroyed under the action of tensile hydrodynamic forces). At low shear rates, a rheological equation should be used that takes into account the additional formation of particle aggregates due to converging hydrodynamic forces. The magnitude of the coefficients (parameters) of the rheological equations for the considered colloidal dispersions corresponds to the conclusions of the structural rheological model, indicating the general mechanism of the flow of these dispersions.