CONTACT ANGLES ON METAL AND POLYMER SURFACES IN MASS-TRANSFER ENVIRONMENTS

Contact angles of pure and binary liquid mixtures measured where the surrounding vapor is not in equilibrium with the liquid are reviewed. Two physical situations were examined which simulated conditions of distillation and condensation. An explanation was afforded as to why at low concentrations when mass transfer took place, some binary mixtures exhibited poor wetting characteristics on metal surfaces but not on polymers. Furthermore, under condensation conditions, the dropwise-filmwise transition was shown to occur at the contact angle of 90-degrees for real systems.