Non-equilibrium properties of semidilute polymer solutions under shear flow

Abstract

We review results of the non-equilibrium properties of semidilute polymer solutions under shear flow. A hybrid simulation approach is adopted, combing molecular dynamics simulations and the multiparticle collision dynamics method, which has been shown to fully capture hydrodynamic interactions. The polymers exhibit a shear rate dependent deformation and alignment. In addition, shear thinning is observed, which is related to the finite polymer extensibility. It is characterized by the shear-rate dependent viscosity and the first normal-stress coefficient. The conformational and rheological properties are universal functions of a concentration dependent Weissenberg number. The cyclic dynamics of an individual polymer is described in terms of a shear-rate dependent tumbling time. The tumbling time is tightly linked to the polymer end-to-end vector relaxation time and depends on concentration, which is attributed to screening of hydrodynamic interactions in semidilute solutions. © Published under licence by IOP Publishing Ltd.