8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P4.26Fri 911:10-14:00Diffusion of tracer particles in hydrogel networksPeter Kosovan, 1 Olaf Lenz, 1 and Christian Holm 11 University of Stuttgart, Institute of Computational Physics, Pfaffenwaldring 27 70569,Stuttgart, GermanyIn this work we consider the diffusion behaviour of a simple spherical tracer particle in polymernetworks of hydrogels. Some Fluorescence Correlation Spectroscopy experiments have suggestedanomalous diffusion of such tracer particles in polymer networks. We use Molecular Dynamics tosimulate tracer particles which tend to stick to the polymer chains. We consider several differentsimplified models, namely tracer bound to diffuse along the polymer contour, tracers diffusing inthe presence of a fixed polymer and tracers diffusing in the presence of a moving polymer. Forthe first model, we observe subdiffusive behaviour on all time scales while for the latter two, it isobserved only on intermediate time scales. We analyze the origin of the subdiffusion in all modelsand discuss the differences and relations to real systems.26