Connecting water correlations, fluctuations, and wetting phenomena at hydrophobic and hydrophilic surfaces

TL;DR

This study uses molecular simulations to link water-water correlations with wetting behavior on various surfaces, revealing how correlations diminish with increased attraction and relate to wetting transitions, demonstrating universal physics.

Contribution

It uncovers the connection between water correlations and wetting phenomena across different surface types using molecular simulations.

Findings

Long-range correlations on superhydrophobic surfaces follow capillary wave theory.

Increasing surface-water attraction quenches water correlations.

Transition from non-wetting to wetting state coincides with loss of long-range correlations.

Abstract

We use molecular simulations to demonstrate the connection between transverse water-water correlations and wetting phenomena for a range of hydrophobic to hydrophilic solid surfaces.Near superhydrophobic surfaces, the correlations are long ranged, system spanning, and are well described by the capillary wave theory. With increasing surface-water attractions, the correlations are quenched. At the critical attraction at which long range correlations disappear, the density profile normal to the surface changes from sigmoidal to layered, and the fluid begins to wet the surface. This behavior is displayed by both water and a Lennard-Jones fluid, highlighting the universality of the underlying physics.