Phase equilibria in stratified thin liquid films stabilized by colloidal particles

Department of Mechanical Engineering, Yale University P.O. Box 20-8286, New Haven, CT 06520, USA

Received: 6 December 2004
Accepted: 12 May 2005

Abstract

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.