Regensburg 2013 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 21: Granular Matter / Contact Dynamics
DY 21.6: Talk
Wednesday, March 13, 2013, 16:15–16:30, H47
Measurement of rotation of individual spherical particles in cohesive granulates — •Jennifer Wenzl1, Ryohei Seto1,2, Marcel Roth1, Hans-Jürgen Butt1, and Günter K. Auernhammer1 — 1Max Planck Institute for Polymer Research, Mainz, Germany — 2Benjamin Levich Institute for Physico-Chemical Hydrodynamics, New York, NY 10031, USA
To explore dynamical processes in granular matter, we use a combination of 3D imaging and mechanical testing. We analyze structural changes using confocal microscopy while applying a compression load simultaneously. Fluorescently labeled polydisperse silica particles were hydrophobized with long alkyl chains and dispersed in an index-matching liquid. The particles show a weak attraction. Photobleaching the central plane of individual particles generates an optical anisotropy without changing particle interaction. In a series of 3D images, we follow trajectories and rotation of single particles [1]. We focus on particle translation and rotation in dependency of the local volume fraction. During compression, restructuring happens predominantly in regions of low packing density. We show that rotation plays an important role and is hence a key parameter for explaining dynamical processes in granular systems.
[1] Wenzl, et al, Granul. Matter (2012), doi:10.1007/s10035-012-0383-7