  We develop a dynamical density functional theory based model for the drying
of colloidal films on planar surfaces. We consider mixtures of two different
sizes of hard-sphere colloids. Depending on the solvent evaporation rate and
the initial concentrations of the two species, we observe varying degrees of
stratification in the final dried films. Our model predicts the various
structures described in the literature previously from experiments and computer
simulations, in particular the small-on-top stratified films. Our model also
includes the influence of adsorption of particles to the interfaces.
