Surface-Directed Spinodal Decomposition: A Molecular Dynamics Study

TL;DR

This study uses molecular dynamics simulations to investigate surface-directed spinodal decomposition in binary fluid mixtures, revealing a crossover in growth behavior influenced by hydrodynamics and providing detailed analysis of layer correlations and domain scales.

Contribution

The paper presents the first molecular dynamics simulation analysis of SDSD, highlighting hydrodynamic effects on growth exponents and detailed structural correlations.

Findings

Wetting layer thickness grows as a power-law with a crossover in growth exponent.

Hydrodynamic effects accelerate domain growth from 1/3 to 1.

Layer-wise correlation functions and domain scales are characterized.

Abstract

We use molecular dynamics (MD) simulations to study surface-directed spinodal decomposition (SDSD) in unstable binary ($AB$) fluid mixtures at wetting surfaces. The thickness of the wetting layer $R_1$ grows with time $t$ as a power-law ($R_1 \sim t^\theta$). We find that hydrodynamic effects result in a crossover of the growth exponent from $\theta\simeq 1/3$ to $\theta\simeq1$. We also present results for the layer-wise correlation functions and domain length scales.