Modeling diffusion of adsorbed polymer with explicit solvent.
Computer simulations of a polymer chain of length N strongly adsorbed at the solid-liquid interface in the presence of explicit solvent are used to delineate the factors affecting the N dependence of the polymer lateral diffusion coefficient, D(||). We find that surface roughness has a large influence, and D(||) scales as D(||) approximately N(-x), with x approximately 3/4 and x approximately 1 for ideal smooth and corrugated surfaces, respectively. The first result is consistent with the hydrodynamics of a "particle" of radius of gyration R(G) approximately N(nu) (nu=0.75) translating parallel to a planar interface, while the second implies that the friction of the adsorbed chains dominates. These results are discussed in the context of recent measurements.
Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York, USA.
Tapan G
TG
Desai
Pawel
P
Keblinski
Sanat K
SK
Kumar
Steve
S
Granick