Dynamics of rigid and flexible polymer chains in confined geometries. part I: steady simple shear flow

This paper describes exact solutions to the response of both the elastic and rigid dumbbell models to a steady simple shear flow in a channel having a length scale comparable to the dumbbells themselves. Results are given for rheological properties over the entire range of the ratio of the channel width to the length of the dumbbell. It is found that both models lead to a decrease in viscosity as the channel is reduced in size with the elastic dumbbell predicting a stronger dependence on that parameter compared with the rigid dumbbell. The elastic dumbbell predicts shear independent rheological properties whereas the rigid dumbell predicts shear thinning as in the case of unbounded flows. The rate of shear thinning, however, decreases with decreasing channel width.