Three-stage phase separation kinetics in a model liquid binary mixture: A computational study.

Area of Science:

• Physical Chemistry
• Materials Science
• Computational Physics

Background:

• Phase separation in liquid mixtures is crucial for material properties.
• Understanding the kinetics of early-stage phase separation is essential.
• Atomistic simulations offer detailed molecular insights into complex fluid dynamics.

Purpose of the Study:

• To investigate the microscopic mechanisms of initial phase separation in a binary liquid mixture.
• To quantify the timescales governing early-stage phase separation kinetics.
• To identify novel features in late-stage phase separation dynamics.

Main Methods:

• Atomistic molecular dynamics simulations.
• Modeling of a structure-breaking liquid binary mixture.
• Analysis of molecular motions and displacements.

Main Results:

• Observed unusual phase separation kinetics with a crossover from exponential to non-exponential dynamics.
• Quantified early-stage exponential phase separation completing within ~100 ps.
• Identified a novel interface smoothing phenomenon in the late stage, contrasting with roughening transitions.

Conclusions:

• Early-stage phase separation involves rapid droplet aggregation and segregation.
• Late-stage separation exhibits power-law-like, non-exponential behavior.
• The study reveals a previously unobserved interface smoothing mechanism in liquid phase separation.