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CPP: Chemische Physik und Polymerphysik
CPP 11: POSTER Disperse Polymer Systems
CPP 11.26: Poster
Dienstag, 28. März 2006, 17:00–19:00, P3
Forces on driven colloids in polymer solutions — •Matthias Krüger1,2, Markus Rauscher1,2, and Siegfried Dietrich1,2 — 1Max-Planck-Institut für Metallforschung, Heisenbergstr. 3, 70569 Stuttgart — 2Institut für Theoretische und Angewandte Physik, Pfaffenwaldring 57, 70569 Stuttgart
Dynamic density functional theory (DDFT) is a dynamic extension of the very successful equilibrium DFT to systems close to equilibrium. It allows to describe the collective dynamics of interacting Brownian particles at the microscopic level in terms of an evolution equation for the particle density. We extend the DDFT to include the effect of solvent flow. In Particular, we study the case of colloids driven through a polymer solution.
We observe accumulation of polymers in front of a driven colloid which gives rise to a friction additionally to the usual Stokes friction. We relate this friction to the diffusivity of a colloid in a polymer solution. We also compare our results to recent experiments measuring the force on a driven colloid in a polymer solution. Between two colloids moving side by side or behind each other, we find repulsive and attractive polymer induced interactions respectively.