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BP: Fachverband Biologische Physik

BP 32: Anomalous Diffusion (joint session DY/BP)

BP 32.9: Talk

Thursday, March 15, 2018, 12:15–12:30, BH-N 334

Obstructed Motion -- from frozen to mobile obstacles — Christoph Zunke, René Hermann, Manuel A. Escobedo-Sanchez, Jörg Bewerunge, •Florian Platten, and Stefan U. Egelhaaf — Condensed Matter Physics Laboratory, Heinrich Heine University, Düsseldorf, Germany

Many natural and industrial processes rely on transport through confined spaces. Confinement by obstacles, for example in porous materials or crowded environments, leads to anomalous diffusion. An idealized situation, the diffusion of point-like tracers through the voids between randomly-placed fixed obstacles, is described by the Lorentz model. Beyond a critical obstacle concentration, the obstacles percolate and hence form finite voids that confine the tracers. Thus the tracer motion becomes localized. However, often the obstacles are mobile, e.g., proteins in biological membranes or organelles in cells. We developed a colloidal model system which permits to tune the particle dynamics through the application of a laser light field. It allows us to study the effect of obstacle mobility. If the obstacles are sufficiently mobile, localization of the tracers is avoided and transient subdiffusion is observed.