Dresden 2011 – scientific programme

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BP: Fachverband Biologische Physik

BP 23: Biopolymers and Biomaterials III (with CPP)

BP 23.2: Talk

Wednesday, March 16, 2011, 15:15–15:30, ZEU 260

Brownian motion of stiff filaments in confined media — •Nikta Fakhri^1,4, Fred MacKintosh², Brahim Lounis³, Laurent Cognet³, and Matteo Pasquali⁴ — ¹Fakultät für Physik, III. Physikalisches Institut - Biophysik , Georg-August-Universität, Göttingen, Germany — ²Department of Physics and Astronomy, Vrije Universiteit, Amsterdam, The Netherlands — ³Centre de Physique Moléculaire Optique et Hertzienne, Université Bordeaux, and CNRS, Talence, France — ⁴Department of Chemical and Biomolecular Engineering, The Smalley Institute for Nanoscale Science and Technology, Rice University, Houston, Texas, USA

The thermal motion of stiff filaments in a crowded environment underlies the behavior of such disparate systems as polymer materials, nanocomposites, and the cell cytoskeleton. Despite decades of theoretical study, the fundamental dynamics of such systems remains a mystery. Using near-infrared video microscopy, we study the thermal diffusion of individual single-walled carbon nanotubes (SWNTs) confined in porous agarose networks. Surprisingly, we find that even a small bending flexibility strongly enhances their motion: the rotational diffusion constant is proportional to the filament bending compliance and is independent of the network porosity. This study establishes definitively the reptation dynamics of stiff filaments and provides a framework to tailor the mobility of SWNTs in confined environments.