Lattice Boltzmann simulations of stochastic thin film dewetting

TL;DR

This paper uses a stochastic lattice Boltzmann method to numerically study how thermal fluctuations and substrate interactions influence the spontaneous dewetting of thin liquid films, revealing effects on rupture times and wettability patterns.

Contribution

It introduces a stochastic lattice Boltzmann simulation approach for thin film dewetting, analyzing the impact of thermal fluctuations and substrate patterns on rupture dynamics.

Findings

Thermal fluctuations shorten rupture times in thin film dewetting.

The ratio of deterministic to stochastic rupture times decreases with contact angle.

Wettability gradients influence dewetting on chemically patterned substrates.

Abstract

We study numerically the effect of thermal fluctuations and of variable fluid-substrate interactions on the spontaneous dewetting of thin liquid films. To this aim, we use a recently developed lattice Boltzmann method for thin liquid film flows, equipped with a properly devised stochastic term. While it is known that thermal fluctuations yield shorter rupture times, we show that this is a general feature of hydrophilic substrates, irrespective of the contact angle. The ratio between deterministic and stochastic rupture times, though, decreases with $\theta$. Finally, we discuss the case of fluctuating thin film dewetting on chemically patterned substrates and its dependence on the form of the wettability gradients.