Shear-induced repulsion of a semiflexible polymer from a wall

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)center dot gamma(2/3)T(1/3)Z(-2) with shear rate 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. Copyright (c) EPLA, 2008.