title: Butler-Sugimoto monomolecular bilayer interface model: the effect of oxygen on the surface tension of a liquid metal and its wetting of a ceramic.
abstract: The influence of oxygen on liquid-gas surface tension of molten metals has been well-investigated experimentally and modeled theoretically via the Szyszkowski equation, derivable from the Butler molecular monolayer interface model. However, there is no corresponding model describing the experimentally observed profound effect of oxygen partial pressure on solid-liquid surface tension as well as on contact angle of molten metals on ceramic substrates. Here, we utilize the Butler-Sugimoto thermodynamic approach based on a monomolecular bilayer interface model to investigate the effect of oxygen partial pressure on liquid-gas as well as solid-liquid surface tension of molten Cu/Al2O3 and molten Ag/Al2O3 systems. It is shown that both liquid-gas and solid-liquid surface tension are a strong function of oxygen activity in the melt, which, in turn, depends on gas-phase oxygen partial pressure, in conformity with experiments. The change in solid-liquid surface tension and wetting is also greatly affected by the change in liquid-gas surface tension. This improved understanding is of practical significance in many applications.
authors.affiliation: Fuel Cell Center, Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, United States.
authors.forename: Pei-Shan
authors.initials: PS
authors.lastname: Yen
authors.affiliation: Fuel Cell Center, Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, United States. Electronic address: rdatta@wpi.edu.
authors.forename: Ravindra
authors.initials: R
authors.lastname: Datta
keywords: Contact angle; Molten metal–ceramic wetting; Oxygen adsorption; Surface tension