  Phase equilibria between regions of different thickness in thin liquid films
stabilized by colloidal particles are investigated using a
quasi-two-dimensional thermodynamic formalism. Appropriate equilibrium
conditions for the film tension, normal pressure, and chemical potential of the
particles in the film are formulated, and it is shown that the relaxation of
these parameters occurs consecutively on three distinct time scales. Film
stratification is described quantitatively for a hard-sphere suspension using a
Monte-Carlo method to evaluate thermodynamic equations of state. Coexisting
phases are determined for systems in constrained- and full-equilibrium states
that correspond to different stages of film relaxation.
