Effect of Annealed Disorder on Phase Separation Kinetics and Aging Phenomena in Fluid Mixtures

TL;DR

This study uses molecular dynamics simulations to investigate how annealed disorder affects phase separation and aging in binary fluid mixtures, revealing slowed dynamics, altered domain growth, and breakdown of superuniversality.

Contribution

It provides new insights into the impact of annealed disorder on phase separation kinetics and aging, highlighting disorder-dependent domain growth and non-superuniversal behavior.

Findings

Disorder causes significant slowing of phase separation.

Domain growth follows a disorder-dependent power-law.

Superuniversality does not hold in disordered systems.

Abstract

We use state-of-the-art molecular dynamics simulations to study the effects of annealed disorder on the phase separating kinetics and aging phenomena of a segregating binary fluid mixture. In the presence of disorder, we observe a dramatic slowing down in the phase separation dynamics. The domain growth follows the power-law with a disorder-dependent exponent. Due to the energetically favorable positions, the domain boundary roughens which modifies the correlation function and structure factor to a non-Porod behavior. The correlation function and structure factor provide clear evidence that the superuniversality does not hold in our system. The role of annealed disorder on the non-equilibrium aging dynamics is studied qualitatively by computing the two-time order parameter autocorrelation function. The decay of the correlation function slows down significantly with the disorder. This quantity exhibits scaling laws with respect to the ratio of the domain length at the observation time and the age of the system. We find the scaling laws hold good for the disordered system and therefore, robust and generic to such segregating fluid mixtures.