We present a Monte Carlo study of the surface anchoring of a nematic fluid on
swollen layers of grafted liquid crystalline chain molecules. The liquid
crystalline particles are modeled by soft repulsive ellipsoids, and the chains
are made of the same particles. An appropriately modified version of the
configurational bias Monte Carlo algorithm is introduced, which removes and
redistributes chain bonds rather than whole monomers. With this algorithm, a
wide range of grafting densities could be studied. The substrate is chosen such
that it favors a planar orientation (parallel to the surface). Depending on the
grafting density, we find three anchoring regimes: planar, tilted, and
perpendicular alignment. At low grafting densities, the alignment is mainly
driven by the substrate. At high grafting densities, the substrate gradually
loses its influence and the alignment is determined by the structure of the
interface between the brush and the pure solvent instead.Comment: Computer Physics Communications, in press. Invited talk at the CCP
200
