Modelling surface tension in binary and ternary systems

A thermodynamic model for calculating surface tension has been implemented using a standard Gibbs energy minimizing software, ChemSheet. The surface is modelled as a monolayer phase, and surface tension values and the composition of the surface layer are is received using the model in a single equilibrium calculation. In the model, surface area is considered a component of the system and the corresponding calculated chemical potential is directly proportional to the surface tension of the mixture. The results are equivalent to with those of the commonly used Butler model and in a good agreement with experimental values. The model can handle mixtures of multiple components and any nonideal mixture phase data compatible with the ChemSheet (ChemApp/ChemSage) data format, while the thermodynamic excess energy equations for the surface phase can be adjusted in the model based on theoretical and empirical considerations for the surface phase interactions. Model cases include binary and ternary metal alloys.