THE EFFECT OF INTERFACIAL MASS-TRANSPORT ON FLOW IN THIN LIQUID-FILMS

The equilibrium thermodynamics and the dynamics of flow in an extended meniscus that includes both the relatively thick film region controlled by capillarity and the ultra-thin film region controlled by the liquid-solid-vapor interfacial force field are analyzed. The effects of capillarity, disjoining pressure, gravity and temperature on equilibrium, fluid flow and mass transfer associated with the liquid film are discussed. The non-equilibrium processes of change-of-phase heat transfer and fluid flow in stationary and in spreading thin films are intrinsically connected because of their common dependence on the intermolecular force field and gravity. Criteria to determine the relative importance of fluid flow and interfacial mass transfer based on the film profile and the thermophysical properties of the system are developed. An evaporation/condensation mechanism is found to be important in contact line motion.