Flow of suspensions with a highly disperse structure-forming fraction

Abstract

A relation is obtained to describe the effect of the volume content of particles on the effective viscosity of a concentrated monodisperse suspension of spherical particles in a medium which can be regarded as a power-law fluid. It is shown that this effect becomes weaker as the nonlinearity of the medium increases. The analysis is performed on the basis of the proposition that the deciding role is played by the lubricant action of thin interlayers of the medium between the surfaces of the particles. These results are used to calculate the viscosity of a bidisperse suspension containing a highly dispersed colloidal fraction and a coarsely dispersed fraction (filler). The viscosity is calculated as a function of the ratio of the two fractions. The calculated results are compared with experimental data for model systems.