Dewetting of Thin Lubricating Films Underneath Aqueous Drops on Slippery Surfaces

TL;DR

This study investigates how thin lubricating oil films beneath aqueous drops on slippery surfaces become unstable and dewet, influenced by film thickness and surface energy, using fluorescence imaging for analysis.

Contribution

It provides experimental insights into the dewetting behavior of thin lubricating films under aqueous drops, highlighting the role of film thickness and surface energy in stability.

Findings

Dewetting dynamics depend on oil film thickness.

Final dewetting patterns are influenced by surface energy.

Fluorescence imaging effectively captures wetting behavior.

Abstract

Stability of thin lubricating fluid coated slippery surfaces depends on the surface energy of the underlying solid surface. High energy solid surfaces, coated with thin lubricating oil, lead to the dewetting of the oil films upon depositing aqueous drops on it. The total surface energy, which is due to the long range and short range interactions, also predict the instability of thin lubricating films under the given condition. In this article, we present experimental study of dewetting of thin lubricating oil films sandwiched between hydrophilic solid surface and aqueous drops. Fluorescence imaging of lubricant film and wetting behavior of aqueous drops are used for the analysis. We find that the dewetting dynamics and the final pattern depend strongly on the thickness of the lubricating oil film.