Predicting surface tension and surface composition of multicomponent liquid mixtures. (I) Ternary mixtures of isopropanol, water, and n-decane or n-tetradecane

Prediction of surface tension and surface composition of multicomponent liquid mixtures remains challenging. A predictive model, called the "surface aggregation adsorption" (SAA) model, was proposed recently, but its applicability needs to be examined, especially for the monophasic solutions containing immiscible components. In this work, the surface tensions of binary and ternary solutions consisting of isopropanol (iPrOH), water, and ndecane (DA) or n-tetradecane (TDA) were determined. Based on the SAA model, the model parameters of the binary (iPrOH-water or DA or TDA) solutions were first estimated, and then used to predict the surface tension and composition of the ternary (iPrOH-water-DA or TDA) solutions. The predicted surface tension values for the ternary solutions are well consistent with their experimental ones. Importantly, the so-obtained information on surface compositions can provide a better understanding of the surface adsorption behavior.