Monte Carlo and numerical self-consistent field study of systems with end-grafted and free polymers in good solvent

We present a systematic Monte Carlo and numerical self-consistent field (NS CF) study of thin films consisting of grafted and free polymers in good sol vent, for the range of densities found in most experiments. Above the overl ap threshold for the grafted polymer, the two approaches agree well. Even a t low densities, the agreement is surprisingly good. The NSCF results are a lso directly compared with experiments. The systematic results are interpre ted in the context of the regimes and behavior predicted by scaling and ana lytic SCF theories. We find that the grafted layer is generally thinner, an d the penetration of the free polymer into the grafted layer is generally g reater than predicted, and that the overall behavior is not in accord with the earlier theories. We find it useful to introduce and distinguish betwee n two measures of the penetration, and we find that one of them can increas e with the concentration of grafted polymer. (C) 2001 American Institute of Physics.