Binary mixtures of rod-like colloids under shear: microscopically-based equilibrium theory and order-parameter dynamics

Rodrigo Lugo-Frías, Sabine H L Klapp
2016 Journal of Physics: Condensed Matter  
This paper is concerned with the dynamics of a binary mixture of rod--like, repulsive colloidal particles driven out of equilibrium by means of a steady shear flow (Couette geometry). To this end we first derive, starting from a microscopic density functional in Parsons--Lee approximation, a mesoscopic free energy functional whose main variables are the orientational order parameter tensors. Based on this mesoscopic functional we then explore the stability of isotropic and nematic equilibrium
more » ... ases in terms of composition and rod lengths. Second, by combining the equilibrium theory with the Doi--Hess approach for the order parameter dynamics under shear, we investigate the orientational dynamics of binary mixtures for a range of shear rates and coupling parameters. We find a variety of dynamical states, including synchronized oscillatory states of the two components, but also symmetry breaking behavior where the components display different in--plane oscillatory states.
doi:10.1088/0953-8984/28/24/244022 pmid:27115342 fatcat:peauq4hg2zdmxlvmfcwh3enzxu