Nonequilibrium structure of concentrated colloidal fluids under steady shear : leading-order response

Abstract

The flow-induced microstructural distortions of dense colloidal dispersions under steady shearing are derived within a recent first-principles approach to the nonlinear rheology of colloidal fluids and glasses. The stationary structure factor is discussed to leading orders in shear rate dot {gamma } . We find that shear affects the stationary structure whenever the dressed Peclet/Weissenberg number mathit {Pe}=dot {gamma }tau becomes appreciable; here τ is the structural or α-relaxation time. Close to vitrification, this predicts significantly larger shear distortions than expected from considering the bare Peclet number Pe0; it compares dot {gamma } with the diffusion time of a colloid at infinite dilution.