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The tension of a curved surface from simulation
Alexander J Sodt1, Richard W Pastor
1National Heart, Lung, and Blood Institute, National Institutes of Health, 50 South Drive, Bethesda, Maryland 20892, USA.
The Journal of Chemical Physics
|December 27, 2012
Summary
This study presents a novel molecular dynamics method to calculate interfacial tension in curved systems. The technique accurately determines tension by analyzing local pressure responses to virtual deformations.
Area of Science:
- Computational chemistry
- Materials science
- Statistical mechanics
Background:
- Calculating interfacial tension in curved systems from molecular dynamics simulations is challenging.
- Existing methods may have limitations in accuracy or applicability.
Purpose of the Study:
- To develop and validate a new method for computing interfacial tension in curved systems using molecular dynamics.
- To resolve ambiguities in local pressure calculation methods relevant to tension computation.
Main Methods:
- Applying local, virtual mechanical deformation to a system subset.
- Fitting the system's response to that of a bulk fluid.
- Utilizing the Young-Laplace equation to infer interfacial tension.
- Comparing results with established methods like Harasima and Irving-Kirkwood.
Main Results:
- The method accurately calculates local pressure in water simulations.
- Computed tension for a curved octane-water interface (≈ 46.7 dyn/cm) agrees well with planar values.
- An ambiguity between Harasima and Irving-Kirkwood methods for local pressure calculation was resolved.
Conclusions:
- The demonstrated method provides a reliable approach for calculating interfacial tension in curved systems from molecular dynamics.
- This technique enhances the ability to study complex interfaces in materials and chemical systems.
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