FREE-ENERGY PROFILES AND SCALING IN POLYMER BRUSHES

Monte Carlo simulations have been performed for an unattached polymer in a grafted polymer layer (a polymer brush). The simulations employ a non-Boltzmann sampling method to calculate the free energy of the unattached chain as a function of its vertical position in the brush, W(z), and the free energy per chain in the grafted layer, f. Contrary to other recent reports, we find grafting conditions where the variation of f is consistent with scaling and analytical self-consistent field (SCF) theories. The free-energy profile, W(z), also follows a form predicted from SCF theory.