Polyelectrolyte stars in planar confinement
arXiv:cond-mat/0603756 · doi:10.1063/1.2202855
Abstract
We employ monomer-resolved Molecular Dynamics simulations and theoretical considerations to analyze the conformations of multiarm polyelectrolyte stars close to planar, uncharged walls. We identify three mechanisms that contribute to the emergence of a repulsive star-wall force, namely: the confinement of the counterions that are trapped in the star interior, the increase in electrostatic energy due to confinement as well as a novel mechanism arising from the compression of the stiff polyelectrolyte rods approaching the wall. The latter is not present in the case of interaction between two polyelectrolyte stars and is a direct consequence of the impenetrable character of the planar wall.
34 pages, 8 figures. Revised version of the manuscript. To appear in J. Chem. Phys. May, 2006