Gas Enrichment at Liquid-Wall Interfaces

TL;DR

This study uses molecular dynamics simulations to explore how dissolved gases enrich at liquid-wall and liquid-gas interfaces, significantly affecting interfacial properties like slip and surface tension.

Contribution

It reveals the extent of gas enrichment at interfaces and its impact on liquid structure and interfacial phenomena, which was previously not well understood.

Findings

Gas enrichment at walls can exceed 100 times the bulk gas density.

Enrichment modifies the liquid structure near the wall, increasing slip.

Gas enrichment at liquid-gas interfaces reduces surface tension.

Abstract

Molecular dynamics simulations of Lennard-Jones systems are performed to study the effects of dissolved gas on liquid-wall and liquid-gas interfaces. Gas enrichment at walls is observed which for hydrophobic walls can exceed more than two orders of magnitude when compared to the gas density in the bulk liquid. As a consequence, the liquid structure close to the wall is considerably modified, leading to an enhanced wall slip. At liquid-gas interfaces gas enrichment is found which reduces the surface tension.