Structure of a Grafted Polymer Brush: A Molecular Dynamics Simulation

We present a detailed simulation study of an end-grafted polymer brush in a good solvent for a range of surface coverages. Each polymer chain consists of between 10 and 150 monomers. We find that the monomer concentration profile aproaches a parabolic form for intermediate values of surface coverage, in agreement with the self-consistent field calculations of Milner et al. rather than the step-function suggested by Alexander. We also determine the distribution of the free ends and find that there is no dead zone; that is, the free end is not excluded from regions near the grafting plane. For higher values of surface coverage, our results deviate qualitatively from the predictions of Milner et al. The dynamics of the chains is also studied. © 1989, American Chemical Society. All rights reserved.