Dresden 2003 – scientific programme

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CPP: Chemische Physik und Polymerphysik

CPP 7: Computational Physics

CPP 7.1: Talk

Tuesday, March 25, 2003, 17:00–17:15, ZEU/160

Shear viscosity of a crosslinked polymer solution — •Henning Löwe, Peter Müller, and Annette Zippelius — Institut für Theoretische Physik, Universität Göttingen, 37073 Göttingen

Starting from a microscopic Zimm model for crosslinked polymers we investigate the critical behaviour of the static shear viscosity at the gelation transition. Hydrodynamic interactions are incorporated within the preaveraging approximation. The scaling behaviour of η_n∼ n^b, the mean contribution to the viscosity η from clusters of a given number of sites n, is investigated numerically for two different probability distributions of the crosslinks, a mean field distribution and distribution according to 3d bond percolation. The shear viscosity η of the crosslinked polymer solution is obtained by summing up the contributions η_n with the appropriate weights determined from the cluster-size distribution. It turns out that in either case the viscosity remains finite when the gelation transition is approached, in contrast to experiments. This clearly demonstrates the failure of the Zimm model.