Polymer margination in uniform shear flows

Abstract

We address the issue of polymer margination (migration towards surfaces) in uniform shear flows through extensive LBMD (lattice-Boltzmann molecular dynamics) simulations. In particular we consider the effect of monomer size, a on the chain's overall margination tendency for chains of length N = 16, 32 monomers in flows at multiple shear rates . We observed higher margination of chains with larger radii monomers in comparison to smaller radii monomer chains of the same length N. We quantify this effect by considering various measures such as the distribution of the maximum extent of the chain into the channel bulk, z_m, distribution of its center of mass in the direction normal to the surface, z_c and the distributions of the chain's radius of gyration in directions parallel and perpendicular to the surface i.e. R_x, R_y and R_z respectively.