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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 44: Micro- and Nanofluidics I
CPP 44.9: Talk
Thursday, March 17, 2011, 16:15–16:30, ZEU 160
Colloidal flow and transport in micro structured porous media — •Frank Wirner1, Christian Scholz1, Yujie Li1,2, and Clemens Bechinger1,2 — 12. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany — 2Max-Planck-Institut für Metallforschung, Heisenbergstrasse 3, 70569 Stuttgart, Germany
Transport and flow phenomena in porous media occur in various fields of science and engineering, ranging from agricultural, biomedical, chemical and petroleum engineering to soil sciences. Although the literature on porous media has been growing rapidly over the last decades it is still unclear, how transport properties of liquids through porous materials can be related to their structure.
We study transport and flow properties of fluids and colloidal suspensions in a quasi 2D microporous system, created using soft lithography, over a wide range of flow regimes. The colloids act as tracer particles and visualize the flow field. A camera system with a temporal resolution of 2 ms and a spatial resolution of 0.4 µm is used to analyze the particle trajectories. The porous structures are artificially designed and therefore the structural parameters like Minkowski functionals and pore size distributions are fully known and can be related to dynamical flow variables, such as permeability or dispersion coefficients. We discuss the relationship between permeability and porosity near and far off the percolation threshold of different random structures.