Fluid-fluid interfacial mobility from random walks

Area of Science:

• Computational physics
• Chemical engineering
• Materials science

Background:

• Fluid-fluid interfaces are crucial in many chemical and physical processes.
• Quantifying interfacial mobility is essential for understanding transport phenomena.
• Existing methods for calculating interfacial mobility are limited.

Purpose of the Study:

• To present the first calculation of fluid-fluid interfacial mobilities using molecular dynamics.
• To develop and validate robust methods for determining interfacial mobility.
• To assess the applicability of these methods across different interface types.

Main Methods:

• Dual control volume grand canonical molecular dynamics simulations were employed.
• Interfacial mobility was calculated from one-dimensional random walks of the interface.
• Three distinct calculation approaches were utilized: interfacial position variance, mean-squared interfacial displacement, and time-autocorrelation of interfacial velocity.

Main Results:

• The study successfully calculated interfacial mobilities for two liquid-liquid and one liquid-vapor interface.
• Excellent agreement was observed between the three distinct calculation methods.
• The findings demonstrate the robustness and reliability of the employed methodologies.

Conclusions:

• The dual control volume grand canonical molecular dynamics approach provides a reliable means to calculate interfacial mobilities.
• The validated methods offer flexibility and accuracy for diverse interfacial systems.
• This work establishes a foundation for further investigations into interfacial transport phenomena.