Conformations of Polymer Melts between Parallel Surfaces: Comparison of the Scheutjens-Fleer Lattice Theory with Monte Carlo Simulations

Abstract

Conformations of chains in polymer melts confined between parallel solid surfaces are examined by means of lattice Monte Carlo (MC) simulations and the Scheutjens-Fleer self-consistent-field (SCF) lattice theory for the purpose of comparing SCF predictions directly with simulation. The effects of surfacechain end interactions on conformational properties of the chains are investigated by considering nonadsorbing, weakly adsorbing, and strongly adsorbing chain ends. Quantitative agreement between MC simulations and SCF theory is found for segment and chain end density distributions and bond orientation profiles. The SCF theory reproduces major features of polymer conformations, as seen in the distributions of loops, tails, trains, and bridges, but quantitative comparisons show considerable differences which are attributed primarily to the reversible walk nature of the SCF theory. It was found that increasing the surface-chain end adsorption energy leads to the formation of more brushlike chain conformations, with more long tails and loops and fewer long train sequences. © 1992, American Chemical Society. All rights reserved.