Calculating the surface tension of binary solutions of simple fluids of comparable size

A molecular theory based on the lattice gas model (LGM) is used to calculate the surface tension of one- and two-component planar vapor–liquid interfaces of simple fluids. Interaction between nearest neighbors is considered in the calculations. LGM is applied as a tool of interpolation: the parameters of the model are corrected using experimental surface tension data. It is found that the average accuracy of describing the surface tension of pure substances (Ar, N2, O2, CH4) and their mixtures (Ar–O2, Ar–N2, Ar–CH4, N2–CH4) does not exceed 2%.