Issue
EPL
Volume 81, Number 5, March 2008
Article Number 54006
Number of page(s) 6
Section Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
DOI http://dx.doi.org/10.1209/0295-5075/81/54006
Published online 19 February 2008
EPL, 81 (2008) 54006
DOI: 10.1209/0295-5075/81/54006

Shear-induced repulsion of a semiflexible polymer from a wall

C. Sendner and R. R. Netz

Physics Department, Technical University Munich - 85748 Garching, Germany


received 8 November 2007; accepted in final form 18 January 2008; published March 2008
published online 19 February 2008

Abstract
We consider the shear-induced repulsion of a single polymer from a no-slip boundary at finite temperature and zero Reynolds number. Extending the asymptotic Fokker-Planck analysis for a dumbbell model to a rod of finite length L, the repulsive force is found to scale as $L^{8/3}\dot{\gamma}^{2/3}T^{1/3}Z^{-2} $ with shear rate $\dot{\gamma} $, temperature T, and surface separation Z. This prediction is confirmed by hydrodynamic simulations for stiff polymers and also found to be approximately valid for semiflexible and (for high enough shear rates) even flexible polymers.

PACS
47.57.Ng - Polymers and polymer solutions.
47.15.G- - Low-Reynolds-number (creeping) flows.
83.10.Mj - Molecular dynamics, Brownian dynamics .

© EPLA 2008