  We present comprehensive molecular dynamics (MD) results for the kinetics of
surface-directed spinodal decomposition (SDSD) and surface enrichment (SE) in
binary mixtures at wetting surfaces. We study the surface morphology and the
growth dynamics of the wetting and enrichment layers. The growth law for the
thickness of these layers shows a crossover from a diffusive regime to a
hydrodynamic regime. We provide phenomenological arguments to understand this
crossover.
