Shear Induced Adsorption of Polymers onto Neutral Surfaces

The dynamics of a single polymer chain in the vicinity of a plane wall, with a short range attractive potential is investigated using MD simulations with long range hydrodynamic interactions. The fluid was modelled using a lattice-Boltzmann algorithm as implemented in the USER/LB package. Polymer unfolding from a globule into a elongated rod like structure was clearly observed. The reversible globule-stretch transition was also observed in cases where the polymer is entirely in the bulk. For relatively strong adhesive strengths, shear induced adsorption is noted in the limit of high shear. Effects of monomer size on the adsorption was also studied and it was found that adsorption is lost entirely as the monomers shrink. Arguments as to why size has an effect are presented. Our results are relevant for understanding protein assisted blood clotting in small ruptured blood vessels.