Self-consistent field/density functional study of conformational properties of polymers at interfaces: role of...

We study the properties of athermal polymers at hard walls using two different versions of self-consistent field theory (SCFT). We calculate the segment density profiles, center of mass profiles, bond orientation vector profiles, and end-to-end vector distributions and compare with grand canonical Monte Carlo simulations. Using the same excess free energy prescription for both theories, we investigate the role of the excluded volume intramolecular interactions on these properties, show the relation between SCFT and density functional theory, and discuss several numerical implementations of the SCFT method. The phantom chain model gives Gaussian chain statistics independent of the conditions. Including the full intramolecular potential leads to an improved description of the low density regime but it does not produce any significant improvement in the semidiluted and concentrated regimes. We show that a viable compromise is achieved by using the effective field resulting from the phantom chain model and by calculating single chain properties using the full intramolecular potential.