Nanostructure of the interface modified by grafted polymers: a Monte Carlo simulation.

The thermodynamic, conformational and orientational properties of polymer melts grafted on a solid substrate were obtained from a novel Monte Carlo (MC) simulation of coarse-grained model of polyethylene (PE). The interface between a non-interacting hard surface and a bulk PE melt, with all chains of which are grafted on the plane, has been studied. Different PE melts, of mean molecular length from C40 and C80, have been investigated, at grafting densities ranging from 0.92 to 1.85 nm. Profiles of monomer density and free end density, bond orientation, and average monomer position along a chain were studied. Quantitative measured in the simulations are derived from the analytical self-consistent field (SCF) theory and compared with the simulation data. The conformational and orientational properties can be quite accurately described by the theory, with some discrepancies observed near the wall and at the tail of the profile. Additional results concerning thermodynamic and surface energy of the brush are also presented.