Modeling surface and line tensions of nanoconfined water using a single atomistic simulation

Area of Science:

• Physics
• Chemistry
• Materials Science

Background:

• Understanding interfacial phenomena like surface tension is crucial in various scientific fields.
• Confined liquids exhibit unique properties compared to their bulk counterparts.
• Accurate calculation of surface and line tensions is essential for modeling nanoscale systems.

Purpose of the Study:

• To calculate liquid-vapor, solid-liquid, and solid-vapor surface tensions, and line tension of water confined between graphene sheets.
• To investigate the relationship between mechanical and thermodynamic approaches for determining line tension.
• To analyze the influence of temperature and confinement on line tension.

Main Methods:

• Utilizing a single molecular dynamics simulation to compute various interfacial tensions.
• Applying a thermodynamic approach based on free energy to determine line tension.
• Relating thermodynamic variables to total stress for consistency checks.

Main Results:

• Surface tensions (γlv, γsl, γsv) and line tension (τ) were calculated for confined water.
• Line tension was found to be negative, irrespective of temperature or confinement level.
• Mechanical and thermodynamic methods were shown to be consistent.

Conclusions:

• The calculated negative line tension aligns with previous findings using different methodologies.
• The developed approach allows for the determination of multiple interfacial properties from a single simulation.
• This method offers a unified way to study interfacial behavior in confined systems.