Macromolecules in nonhomogeneous velocity gradient fields. II

Bead-spring model macromolecules in nonhomogeneous flows migrate relative to the local solvent velocity at the center of mass. We show that this is the result of the net viscous forces acting on all the beads. The analogy between these results and continuum mechanical results on suspensions of neutrally buoyant rigid particles is discussed. Detailed comparisons of this model with the available experimental data in the concentric cone geometry is made. Models with linear springs are found to over-predict the migration somewhat, but all qualitative features of the phenomenon are well represented. This provides a new means of testing macromolecular models.