An innovative model for correlating surface tension, solubility parameters, molar volume and ratio of the coordination numbers of liquid metals, based on Stefan's rule

Abstract

Surface tension has direct applications in the field of material science, playing a key role in applications such as metal alloy formation, phase match/ separation, nanodispersion and organometallic synthesis for chemical industrial purposes. Although extensively used, the accurate surface tension of liquid metals is difficult to measure due to the high boiling point; it is therefore important to achieve theoretical or empirical methods for predicting it. Semi-empirical predictions based on the correlation between the surface and bulk thermodynamic properties of liquid metals are possible, such as linking surface tension to the heat of evaporation. Formerly, on the basis of a computer regression of a large database, Beerbower (1971) [3] showed a relationship between the Hildebrand solubility parameter, surface tension and molar volume, which applies for both organic molecules and metal liquids. More recently, Strechan et al. (2006) [10] introduced a relationship between the ratio of the coordination numbers, surface tension, molar volume and enthalpy of vaporization of organic molecules, using Stefan's rule as a physicochemical background. The present study introduces a novel semi-empirical relationship based on the correlation between the surface and bulk thermodynamic properties of liquid metals and the Hildebrand solubility parameter. The original inclusion of the ratio of the coordination numbers to Stefan's rule strengthens the relationship between the solubility parameters and the physical backgrounds they represent and enhances the computational accuracy of predicted liquid metals surface tension.