Molecular Simulations of Dewetting

TL;DR

This paper uses molecular dynamics simulations to study the breakup and flow of thin partially wetting liquid films on solid surfaces, revealing a spinodal instability and complex rim dynamics.

Contribution

It provides new molecular-level insights into dewetting phenomena, confirming theoretical predictions and highlighting discrepancies in rim fluid dynamics.

Findings

Films below critical thickness show spinodal-like instability.

Dry patches form spontaneously during dewetting.

Rim fluid dynamics partially agree with previous models.

Abstract

We have studied the breakup and subsequent fluid flow in very thin films of partially wetting liquid on solid substrates, using molecular dynamics simulations. The liquid is made of short chain molecules interacting with Lennard-Jones interactions, and the solid is modeled as a clean crystal lattice whose atoms have thermal oscillations. Films below a critical thickness are found to exhibit a spontaneous spinodal-like instability leading to dry patches, as predicted theoretically and observed in some experiments. Liquid withdrawing from a dry patch collects in a moving rim whose fluid dynamics is only partially in agreement with earlier predictions.