Adsorption Transition of a Polyelectrolyte on a High-dielectric Charged Substrate

The behavior of a polyelectrolyte adsorbed on a charged surface of high-dielectric constant is studied by both Monte-Carlo simulation and analytical methods. It is found that in a low ionic strength medium, the transition is first-order with the repulsive charged surface. The order parameter which characterize the polyelectrolyte adsorption, the surface monomer density, follows a linear relation with surface charge density. It indicates the polyelectrolyte is always compressed on the substrate. No conformation change exists before the de-sorption. Finally, a new scaling law for the layer thickness is derived and verified by the simulation data.