Volume 85, Number 3, February 2009
Article Number 30003
Number of page(s) 6
Section General
Published online 03 February 2009
EPL, 85 (2009) 30003
DOI: 10.1209/0295-5075/85/30003

Effective Perrin theory for the anisotropic diffusion of a strongly hindered rod

T. Munk, F. Höfling, E. Frey and T. Franosch

Arnold Sommerfeld Center for Theoretical Physics (ASC) and Center for NanoScience (CeNS), Fakultät für Physik, Ludwig-Maximilians-Universität München - Theresienstraße 37, 80333 München, Germany, EU

received 15 September 2008; accepted in final form 7 January 2009; published February 2009
published online 3 February 2009

Slender rods in concentrated suspensions constitute strongly interacting systems with rich dynamics: transport slows down drastically and the anisotropy of the motion becomes arbitrarily large. We develop a mesoscopic description of the dynamics down to the length scale of the interparticle distance. Our theory is based on the exact solution of the Smoluchowski-Perrin equation; it is in quantitative agreement with extensive Brownian dynamics simulations in the dense regime. In particular, we show that the tube confinement is characterised by a power law decay of the intermediate scattering function with exponent 1/2.

05.20.-y - Classical statistical mechanics.
61.20.Lc - Structure of liquids: Time-dependent properties; relaxation.

© EPLA 2009