LINEAR VISCOELASTICITY OF DENSE COLLOIDAL SUSPENSIONS

In earlier exact calculations of the linear viscoelastic behavior of semidilute suspensions of hard spheres we have shown that hydrodynamic interactions have a significant influence on the frequency dependence of the dynamic shear viscosity. Scaling with the mean relaxation time is not sufficient. Here we reanalyze experimental data of van der Werff et al. on the linear viscoelasticity of dense hard sphere suspensions with hydrodynamic interactions, and determine values of the parameters characterizing the shape of the dispersion curves. We find that the data cannot be explained by scaling the exact result for a semidilute suspension of hard spheres without hydrodynamic interactions with just the mean relaxation time.