Using isothermal-isobaric Monte Carlo simulation to study the wetting behavior of model systems.
Karnesh Jain1, Kaustubh S Rane1, Jeffrey R Errington1
1Department of Chemical and Biological Engineering, University at Buffalo, Buffalo, New York 14260-4200, USA.
The Journal of Chemical Physics
|March 3, 2019
Summary
We developed a new molecular simulation method to calculate interfacial properties using the isothermal-isobaric ensemble. This approach accurately determines spreading coefficients, surface tension, and contact angles for fluid-substrate systems.
Area of Science:
- Physical Chemistry
- Materials Science
- Computational Physics
Background:
- Interfacial properties are crucial for understanding fluid behavior at surfaces.
- Accurate computation of these properties is essential for materials design and process optimization.
- Existing simulation methods may have limitations in efficiency or applicability.
Purpose of the Study:
- To introduce a novel molecular simulation method for computing interfacial properties.
- To implement this method within the isothermal-isobaric ensemble for enhanced sampling.
- To validate the approach by calculating key macroscopic properties like surface tension and contact angles.
Main Methods:
- Utilized a free-energy-based approach with Monte Carlo simulations.
- Employed "spreading" and "drying" frameworks to calculate interface potentials.
- Introduced local volume change moves to improve sampling efficiency in inhomogeneous systems.
- Applied expanded ensemble techniques for broad temperature and substrate strength analysis.
Main Results:
- Successfully computed spreading and drying coefficients directly from interface potentials.
- Determined liquid-vapor surface tension and contact angles for a Lennard-Jones fluid on a substrate.
- Demonstrated improved sampling efficiency with local volume change moves.
- Compared results with previous grand canonical ensemble calculations.
Conclusions:
- The isothermal-isobaric ensemble offers an effective framework for calculating interfacial properties.
- The developed method provides direct access to macroscopic interfacial parameters.
- Local volume changes enhance the simulation of inhomogeneous systems, offering a more efficient approach.
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