Surface-enhanced unfolding of collapsed polymers in shear flow

Using hydrodynamic simulations we study the shear-induced unfolding of a collapsed polymer near a planar wall. Above a well- de. fined threshold shear rate gamma*, the globule becomes unstable and displays stretching-refolding events. With decreasing distance from the surface, the critical shear rate gamma* goes down, which is rationalized within a scaling analysis in terms of increased hydrodynamic stress due to a surface-induced slowing-down of globule rotation and translation. Our results are relevant for protein-assisted blood clotting in capillary vessels. Copyright (C) EPLA, 2007.