Pressure-deformation relations of elasto-capillary drops (droploons) on capillaries
Gaël Ginot1, Felix S Kratz2, Friedrich Walzel1
1Institut Charles Sadron, CNRS UPR22 - Université de Strasbourg, Strasbourg, France. wiebke.drenckhan@ics-cnrs.unistra.fr.
Soft Matter
|September 27, 2021
Summary
Researchers developed simple analytical methods to measure the elastic properties of complex interfaces in multi-phase systems. This technique, "Capillary Pressure Elastometry," simplifies the analysis of elasto-capillary droplets, overcoming challenges with traditional pendant drop methods.
Area of Science:
- Soft Matter Physics
- Interfacial Science
- Materials Characterization
Background:
- Multi-phase systems increasingly utilize complex interfaces with coupled capillary and elastic stresses.
- Experimental characterization of these interfaces, particularly dilational properties, remains challenging.
- Pendant drop techniques are limited by complex shape changes and multi-parameter fitting.
Purpose of the Study:
- To develop simple, reliable experimental methods for characterizing elasto-capillary interfaces.
- To derive analytical relationships for pressure-deformation in elasto-capillary droplets.
- To establish criteria for using simplified models in analyzing interfacial elastic properties.
Main Methods:
- Modeling interfaces with superimposed constant interfacial tension and neo-Hookean solid-like extra-stresses.
- Comparing Gibbs (liquid-like) and Hookean/neo-Hookean (solid-like) elasticity models.
- Utilizing Surface Evolver simulations and numerical integration of drop shape equations.
- Analyzing the influence of capillary-induced anisotropic deformation.
Main Results:
- Simple analytical relationships accurately describe pressure-deformation for elasto-capillary droplets ('droploons').
- Analytical relations for perfect spheres or slightly modified versions are applicable in many experimental scenarios.
- Non-dimensional criteria predict when simple analytical expressions can reliably fit data for 'Capillary Pressure Elastometry'.
- Surface Evolver is validated as a reliable tool for simulating elastocapillary interfaces.
Conclusions:
- The developed analytical framework simplifies the measurement of interfacial elastic properties.
- The criteria enable accurate analysis of elasto-capillary interfaces using simplified models.
- This work facilitates the study of complex interfacial phenomena and opens avenues for advanced simulations.
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