Mesoscale hydrodynamics simulations of particle suspensions under shear flow: From hard to ultrasoft colloids

Abstract

We discuss the nonequilibrium properties of rodlike and ultrasoft, star-polymer like colloidal particles in shear flow. Conformational, dynamical, as well as rheological aspects are addressed for a broad range of concentrations. For concentrated solutions of rodlike colloids, we study the nonequilibrium properties of a phase separated system, where a disordered phase coexists with a nematic phase. For starlike polymers we consider systems of various functionality, starting from linear polymers. The individual rods, polymers, or stars exhibit an intriguing dynamical behavior, which determines their macroscopic rheological properties. Despite the diversity on the colloidal level, the various systems exhibit a qualitatively similar macroscopic behavior, e.g., shear thinning, yet with some quantitative differences.