Shear induced polymer migration: analysis of the evolution of concentration profiles

In order to analyze the evolution of the concentration profile experimental ly observed by MacDonald and Muller under shear-induced polymer migration i n a rotating cone-and-plate device, we use a constitutive equation for the diffusion flux, where the gradient of a generalized non-equilibrium chemica l potential appears instead of the concentration gradient. From this model of coupling between diffusion and viscous pressure, together with the mass balance equation, we derive some general features of the concentration prof ile, the temporal behavior of the polymer concentration near the apex of th e cone and some relevant trends of the dynamical process of polymer migrati on. (C) 2000 Elvevier Science Ltd. All rights reserved.