Rheology of Concentrated Colloidal Suspensions in the Approach of the Glass Transition

Concentrated, non-crystallizing colloidal suspensions in their approach of the glass state exhibit distinct dynamics patterns. This is demonstrated with a model suspension at increased volume fraction of solid. The glass is defined by arrested motion of the spherical suspension particles. Dynamic mechanical experiments suggest a powerlaw rheological constitutive model for near-glass viscoelasticity as presented here. The rheological parameters used for this model originate in the Mode-Coupling Theory. The proposed constitutive model provides explicit expressions for the steady shear viscosity, the steady normal stress coefficient, the modulus-compliance relation, and the \textit{$\alpha $}-peak of $G$''. The relaxation pattern distinctly differs from gelation.