(239g) Coupling between Attractions and Repulsions in Flow of Colloidal Suspensions

Theories and simulations of colloidal suspensions have been successful in capturing many important features found in flow experiments. This includes systems with strong repulsions to stabilize the suspension or with strong attractions that lead to phase separation or gel formation. Less attention has been paid to suspensions with simultaneous weaker attractions and repulsions. This is particularly important for designing suspensions by manipulating the colloidal interactions and in the flow properties of biological materials. In this talk we will focus on how the coupling between the attractions and repulsions alters the zero-shear-rate viscosity. We will show how two systems can have the same effective interaction while also having very different viscosities. We will also show how repulsions can be used to either increase or decrease the viscosity. These both have implications for designing suspensions and understanding experimental observations.