COLLISIONS OF POLYMER-COATED COLLOIDAL SPHERES IN A LINEAR SHEAR-FLOW

The interactions between polymer-coated colloidal spheres were investigated by direct observation. A force model was assumed in order to determine the effect of the adsorbed polymer layer during particle collisions. It was concluded that the interpenetration of the polymer layers was not extensive and that the mechanism of stability (in low shear) involved preventing approach to a distance where van der Waals attraction would become significant. A simple model was used to demonstrate that the equations governing two-sphere trajectories in shear flow are not complete as they do not account for the viscopolymeric coupling forces. © 1992.