Molecular fields and statistical field theory of fluids: Application to interface phenomena

Area of Science:

• Statistical mechanics
• Fluid dynamics
• Physical chemistry

Background:

• Understanding fluid interfaces is crucial in various scientific disciplines.
• Existing models for surface tension often require empirical parameters.
• A microscopic, parameter-free approach is needed for accurate predictions.

Purpose of the Study:

• To develop a field-theoretical Hamiltonian for statistical fluid theory.
• To derive an analytical expression for surface tension at the liquid-vapor interface.
• To provide a physical interpretation of the statistical field within the theory.

Main Methods:

• Integral transformation techniques were employed to obtain the field-theoretical Hamiltonian.
• Microscopic expressions for Hamiltonian coefficients were derived.
• The approach was applied to the liquid-vapor interface to calculate surface tension.

Main Results:

• An explicit analytical expression for surface tension was derived, dependent on temperature, density, and intermolecular potential parameters.
• The formal statistical field was linked to a one-body local microscopic potential, offering physical insight.
• The theoretical results showed good agreement with simulation data, validating the approach.

Conclusions:

• The developed statistical field theory provides a robust, parameter-free method for calculating surface tension.
• The theory offers a clear physical interpretation of microscopic interactions at fluid interfaces.
• This approach advances the understanding of liquid-vapor interfaces and their properties.