Measurement and Prediction of Interfacial Tension of Binary Mixtures

Abstract

The density gradient theory was combined with a modern equation of state based on statistical mechanics, the perturbed chain-statistical association fluid theory, or with the well-known Peng-Robinson equation of state, and is applied to compute the surface tension of various binary mixtures made up of nonpolar substances. Additionally, some new data for the system methane + hexane and methane + heptane were measured using the pendant drop method equipped with a high-pressure cell. Both equations of state can be used to predict the surface tension of mixtures very close to experimental data. The surface tension of pure ethane could also be predicted using the surface tension data of other n-alkanes. Additionally, the surface tensions for mixtures as a function of liquid composition, of temperature, and of pressure were calculated for systems, where no experimental data are available. If the mixture contains a high volatile component, strong relative enrichment effects in the interface could be observed.

Phase equilibrium and interfacial properties of water+CO2 mixtures

“…Therefore, it is decisive to develop a methodology that is able to give not only a description of both phase-and interfacial behavior, but also that is able to use the given data in the literature for predictive estimation of them. Previous works [1][2][3] have shown the ability of prediction of the density gradient theory (DGT) [4][5][6] in combination with a suitable equation of state in the case of polar and non-polar mixtures. This paper concentrates on the further development of this methodology using the DGT in combination with the perturbed chain polar statistical associating fluid theory equation of state (PCP-SAFT EOS) [7].…”

“…Despite all this, no methodology seems to be able to describe the CO 2 + water system close to the experimental date over a wide temperature and pressure range. It is therefore important to see how the methodology from previous works [1][2][3] can be applied for a much more complex mixture.…”

Classical density functional theory for the prediction of the surface tension and interfacial properties of fluids mixtures of chain molecules based on the statistical associating fluid theory for potentials of variable range

“…, associating mixtures of water + alkanols 47 , and mixtures of hydrocarbons and aromatics 48 . Numerous studies in which a SAFT-like description is used within a DGT formalism to describe the interfacial properties of fluid mixtures have now been made [49][50][51][52][53][54] .…”

Прогнозування Поверхневих Властивостей Холодоагентів На Основі Градієнтної Теорії З Кубічним Рівнянням Стану

“…К достоинствам указанно-го типа УС следует отнести их очевидный термо-динамический смысл, простоту и возможность предсказывать параметры фазового равновесия чистых веществ и растворов. Совместное исполь-зование градиентной теории и кубического УС Пенга-Робинсона впервые было применено в рабо-те Кэри [14] и с тех пор неоднократно использова-лось для расчета поверхностного натяжения чи-стых веществ и многокомпонентных смесей и дру-гими исследователями [18][19][20].…”