Phase Separation in Binary Fluid Mixture with Quenched Disorder

Abstract

Quenched or frozen-in, structural disorder is ubiquitous in real experimental systems. Much of the progress is achieved in understanding the phase separation of such systems using diffusion-driven coarsening in Ising model with quenched disorder. But there is a paucity of research in the phase-separation kinetics in fluids with quenched disorder. In this letter, we present results from a detailed Molecular dynamics (MD) simulation the effects of randomly placed localized impurities on the phase separating kinetics of binary fluid mixture. Our system resembles the fluid imbibed into a porous medium. We observe a dramatic slowing down in the pattern formation with increasing pin particle concentration. 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