Studies of the viscosity and sedimentation of suspensions Part 2. - The viscosity and sedimentation of suspensions of rough powders

Abstract

The viscosity of suspensions of rough methyl-methacrylate powders in aqueous solutions is shown to increase at all concentrations as the particle size is reduced. This is explained on the assumption that the individual particles behave as if surrounded by a layer of immobile liquid, held in the irregularities of their surfaces. The thickness of the layer, for a particular material, is independent of the viscosity of the suspending liquid, the concentration of the suspension and the size of the particles above a certain minimum value below which it decreases continuously with particle size. Sedimentation experiments made on suspensions of the same particles confirm these conclusions.