A MONTE-CARLO SIMULATION STUDY OF THE DISJOINING PRESSURE IN THIN FLUID FILMS STERICALLY STABILIZED BY TERMINALLY ATTACHED CHAINS

A Monte Carlo simulation study of the steric component to the disjoining pressure of a thin fluid film is presented for a system with parallel planar surfaces bearing terminally attached chains. A continuum model of freely jointed linear chains with excluded volume interaction in the good solvent regime is used. Results for the segment density profile as a function of film thickness are obtained which show a considerable degree of interpenetration of the two attached chain layers at small surface separations. The disjoining pressure is found to be purely repulsive and a strong function of the surface coverage. The disjoining pressure displays a much weaker dependence on the chain length. The results are compared and contrasted with those from a lattice-based mean field theory.