Application of the interface potential approach for studying wetting behavior within a molecular dynamics framework.

Area of Science:

• Computational chemistry
• Materials science
• Physical chemistry

Background:

• Wetting properties, such as contact angle, are crucial for understanding liquid-solid interactions.
• Accurate computation of these properties is essential in various scientific and engineering fields.
• Existing methods may face limitations in efficiency and applicability.

Purpose of the Study:

• To develop and validate a molecular dynamics framework for computing wetting properties.
• To implement both "drying" and "spreading" versions of the interface potential approach.
• To investigate the influence of simulation parameters on method efficiency and accuracy.

Main Methods:

• Utilized the interface potential approach within a molecular dynamics (MD) framework.
• Employed umbrella sampling with an isothermal-isobaric ensemble to restrain volume fluctuations.
• Compared two free energy methods: cumulative integration of average force profile and multistate Bennett acceptance ratio.
• Implemented coupled MD/Monte Carlo for the spreading potential to address vapor phase evolution limitations.

Main Results:

• Successfully generated the drying potential for liquid droplets on solid substrates.
• Demonstrated that method efficiency depends significantly on the handling of confining wall dynamics.
• Found that MD alone was insufficient for simulating the spreading potential due to slow vapor phase evolution.
• Showcased the ability to determine variations in interfacial properties with temperature and substrate strength.

Conclusions:

• The developed MD framework is effective for computing drying potentials.
• A hybrid MD/Monte Carlo approach is necessary for accurately simulating spreading potentials.
• The study provides insights into optimizing simulations of wetting phenomena and understanding interfacial properties.