(390b) Constant Stress and Pressure Rheology of Colloidal Suspensions

Brady, J. F., California Institute of Technology / Division of Chemistry and Chemical Engineering
Wang, M., California Institute of Technology

We study the constant stress and pressure rheology of dense hard-sphere colloidal suspensions from a granular perspective using Brownian dynamics simulations. In the non-Brownian limit, the Shear Arrest Point (SAP) emerges from the collapsing rheolgical data, and the simulations quantitatively agree with the experiments of Boyer et al. [Phys. Rev. Lett. 107, 188301 (2011)] through a scaling factor. Near the suspension arrest, both the shear and the incremental normal viscosities display universal power law divergences, and the particle diffusion is connected to the suspension osmotic pressure through a Stokes-Einstein-Sutherland-like relation. Our work clearly shows the fundamental role of jamming physics on the arrest of colloidal suspensions, and illustrates the great care needed when conducting and analyzing experiments and simulations near the flow-arrest transitions.