Tumbling of polymers in semidilute solution under shear flow

¹ Institute of Complex Systems, Forschungszentrum Jülich - D-52425 Jülich, Germany, EU
² Jülich Supercomputing Centre, Forschungszentrum Jülich - D-52425 Jülich, Germany, EU
³ Institute for Advanced Simulation, Forschungszentrum Jülich - D-52425 Jülich, Germany, EU

^a r.winkler@fz-juelich.de

Received: 6 December 2010
Accepted: 11 February 2011

Abstract

The tumbling dynamics of individual polymers in semidilute solution is studied by large-scale non-equilibrium mesoscale hydrodynamic simulations. We find that the tumbling time is equal to the non-equilibrium relaxation time of the polymer end-to-end distance along the flow direction and strongly depends on concentration. In addition, the normalized tumbling frequency as well as the widths of the alignment distribution functions for a given concentration-dependent Weissenberg number exhibit a weak concentration dependence in the cross-over regime from a dilute to a semidilute solution. For semidilute solutions a universal behavior is obtained. This is a consequence of screening of hydrodynamic interactions at polymer concentrations exceeding the overlap concentration.