VISCOSITY AND STRUCTURAL RELAXATION IN CONCENTRATED HARD-SPHERE COLLOIDS

Measurements of the low-shear-rate viscosity of a model hard-sphere su spension are presented. Suspension volume fractions are calibrated wit h respect to the thermodynamic disorder to order, or crystallization, transition. At freezing, the low-shear suspension viscosity is found t o be approximate to 53 times that of the solvent. This result is discu ssed in the light of the considerable literature on hard-sphere suspen sion viscosity. Particle dynamics in the same suspensions is studied b y two-colour dynamic light scattering. We find that the inverse struct ural relaxation time scales exactly as the suspension viscosity.