Kinetics of phase separation in fluids: a molecular dynamics study

Area of Science:

• Computational physics and chemistry
• Materials science
• Fluid dynamics

Background:

• Phase separation is a fundamental process in materials science and fluid dynamics.
• Understanding the kinetics of phase separation is crucial for controlling material properties.
• Previous studies often relied on simplified models or experimental observations.

Purpose of the Study:

• To investigate the kinetics of phase separation in fluids using advanced computational methods.
• To compare the coarsening dynamics of fluids with those of solids.
• To characterize the underlying velocity field and its impact on the structure factor.

Main Methods:

• Extensive three-dimensional molecular dynamics (MD) simulations were performed.
• A coarse-graining procedure was employed to achieve state-of-the-art simulation results.
• Analysis included quantifying morphological similarities and characterizing the velocity field.

Main Results:

• An extended period of temporally linear growth was observed in the viscous hydrodynamic regime.
• Quantitative similarities in coarsening morphology between fluids and solids were identified.
• Monopole-like defects in the velocity field were characterized, leading to a generalized Porod tail in the structure factor.

Conclusions:

• The study provides detailed insights into fluid phase separation kinetics through advanced MD simulations.
• The findings highlight universal aspects of coarsening across different phases of matter.
• The identified velocity field defects offer a new perspective on the structure formation during phase separation.