关键词: interfacial tension;molecular thermodynamic model;perturbation theory;surfactant-oil- water system

Abstract:

An interfacial equation of state based on perturbation theory for surfactant-oil-water
system has been developed. By combining the interfacial equation of state with Boudh-Hir
and Mansoori’s model, a molecular ther- modynamic model has been proposed. The interfacial
tension of surfactant-oil-water systems can be calculated from the surface tensions of pure
oil and water by this model. The inteffacial tension data for sodium dodecyl sulphate-
heptane-water system, polyoxyethylene n-octylphenol-heptane-water system and hexadecyl
trimethyl ammonium bromide-heptane-water system have been correlated. By using the
adjustable parameters obtained, the interfacial tensions of these systems at other
temperatures have been predicted. Both the correlated and the predicted values are
satisfactory.

Key words: interfacial tension, molecular thermodynamic model, perturbation theory, surfactant-oil- water system