| Abstract
| - We examine the effects of polymer layer anisotropy (bond correlations) on the numericalmean-field predictions of the interactions between two physisorbed polymer layers under restrictedequilibrium conditions. Lattice mean-field calculations are presented for two models based on second-order Markov chains (i.e., without backfolding), one in an isotropic mean field and another in an anisotropicmean field. The results from lattice Monte Carlo simulations are used as a reference to examine thoseobtained from the numerical mean-field theories. It is found that the numerical mean-field theories predictthe structural features of the polymer layer fairly well but are limited in the predictions of the interactionforces. The effects of anisotropy near and away from the adsorbing surface differ from each other but arestill insufficient to capture the interactions accurately. Introduction of anisotropy results in higher segmentdensities of trains but lower segment densities of loops, tails, and bridges and, consequently, lower stericinteractions. It is seen that the mean-field theories can at best offer qualitative information on the structureof the adsorbed layer and of the interaction forces at conditions where steric interactions become important(at high coverages). At conditions where bridging interactions dominate (at low coverages), the mean-field theories fail to capture the bridging attraction between the surfaces (as expected), in contrast tosome of the earlier published reports.
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