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Interface tension, interface Gibbs free energy and contact angle
Bronisław Jańczuk1, Anna Zdziennicka1, Katarzyna Szymczyk1
1Department of Interfacial Phenomena, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University in Lublin, Maria Curie-Skłodowska Sq. 3, 20-031 Lublin, Poland.
Advances in Colloid and Interface Science
|May 17, 2026
Summary
This study reviews methods for calculating solid surface tension and liquid-solid interface energy using Young
Area of Science:
- Surface science
- Physical chemistry
- Materials science
Background:
- The Young equation relates surface tension and contact angle.
- Calculating solid surface tension and solid-liquid interface energy requires understanding relationships between solid-liquid interface tension and surface energies of solid and liquid phases.
- Existing approaches to these relationships are categorized into two main groups based on their dependence on intermolecular interactions.
Purpose of the Study:
- To analyze various approaches for determining solid surface tension and solid-liquid interface energy.
- To evaluate the applicability of these approaches for predicting interface tensions and wettability of solids by liquids.
- To reconcile literature values of surface and interface free energy with surface and interface tensions.
Main Methods:
- Review and categorization of existing theoretical approaches relating interface tension to surface tension.
- Analysis of approaches based on whether they consider intermolecular interactions or solely surface tension values.
- Application of thermodynamics of irreversible processes to interpret contact angle as a function of surface tensions.
Main Results:
- Two primary groups of approaches for interface tension calculations were identified: one dependent only on surface tensions, the other considering intermolecular interactions.
- The study analyzed the components and parameters of surface tension based on different intermolecular interactions and their relevance to each approach.
- The applicability of these methods for predicting solid wettability by liquids with varying hydrophobic/hydrophilic properties was assessed.
Conclusions:
- The Young equation, within the framework of irreversible thermodynamics, establishes contact angle as a function of liquid and solid surface tensions at the time of measurement.
- Literature values for surface and interface free energy derived from the Young equation can be treated as surface and interface tensions.
- Understanding the interplay between intermolecular forces and surface tension is crucial for accurate predictions of solid-liquid interactions and wettability.
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