| Abstract
| - We have performed molecular dynamics simulations of polyelectrolyte adsorption at oppositely charged surfacesfrom dilute polyelectrolyte solutions. In our simulations, polyelectrolytes were modeled by chains of charged Lennard-Jones particles with explicit counterions. We have studied the effects of the surface charge density, surface chargedistribution, solvent quality for the polymer backbone, strength of the short-range interactions between polymers andsubstrates on the polymer surface coverage, and the thickness of the adsorbed layer. The polymer surface coveragemonotonically increases with increasing surface charge density for almost all studied systems except for the systemof hydrophilic polyelectrolytes adsorbing at hydrophilic surfaces. In this case the polymer surface coverage saturatesat high surface charge densities. This is due to additional monomer−monomer repulsion between adsorbed polymerchains, which becomes important in dense polymeric layers. These interactions also preclude surface overchargingby hydrophilic polyelectrolytes at high surface charge densities. The thickness of the adsorbed layer shows monotonicdependence on the surface charge density for the systems of hydrophobic polyelectrolytes for both hydrophobic andhydrophilic surfaces. Thickness is a decreasing function of the surface charge density in the case of hydrophilic surfaceswhile it increases with the surface charge density for hydrophobic substrates. Qualitatively different behavior isobserved for the thickness of the adsorbed layer of hydrophilic polyelectrolytes at hydrophilic surfaces. In this case,thickness first decreases with increasing surface charge density, then it begins to increase.
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