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Updated: Jul 10, 2026
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Accurate Determination of the Equilibrium Surface Tension Values with Area Perturbation Tests
Published on: August 30, 2019
Predicting interfacial tension between water and nonpolar fluids from a Cahn-type theory
Virenkumar Shah1, Daniel Broseta
1Laboratoire des Fluides Complexes, UMR 5150, Université de Pau et des Pays de l'Adour, BP1155, 64013, Pau Cedex, France.
Langmuir : the ACS Journal of Surfaces and Colloids
|November 2, 2007
Summary
This study introduces a new method to predict interfacial tension (IFT) between water and nonpolar fluids using Cahn gradient theory. The approach offers a universal, parameter-free prediction for IFT, applicable across various conditions.
Area of Science:
- Physical Chemistry
- Thermodynamics
- Materials Science
Background:
- Interfacial tension (IFT) is critical for understanding fluid behavior and phase transitions.
- Accurate prediction of IFT between water and nonpolar fluids is essential for various chemical and engineering applications.
- Existing methods often require empirical parameters or are limited in scope.
Purpose of the Study:
- To develop an accurate and predictive method for calculating interfacial tension between water and nonpolar fluids.
- To establish a universal relationship for water contact energy applicable across different nonpolar adsorbates and temperatures.
- To provide a parameter-free approach for IFT estimation based on fundamental physical principles.
Main Methods:
- Utilizing Cahn gradient theory to model the interface between water and nonpolar fluids.
- Employing a water contact energy function and the Peng-Robinson equation of state for the nonpolar fluid.
- Relating contact energy to interfacial tension via the Gibbs adsorption equation.
Main Results:
- Identified a universal function for water contact energy dependent on adsorbate surface density, independent of adsorbate type or temperature.
- Demonstrated a corresponding-states principle governing interfacial behavior for sparingly soluble nonpolar compounds.
- Developed a predictive, parameter-free method for estimating IFT for both subcritical and supercritical nonpolar fluids.
Conclusions:
- The proposed method accurately predicts interfacial tension between water and sparingly soluble nonpolar fluids.
- The method shows slight overestimation for highly soluble adsorbates like CO2 and H2S.
- The findings suggest potential applicability to interfaces involving solid substrates.
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