Effects of van der Waals forces and salt ions on the growth of water films on ice and the detachment of CO$_2$ bubbles

TL;DR

This study investigates how salts influence water film thickness on melting ice and CO2 bubble interactions, highlighting the roles of van der Waals and electrostatic forces with model-dependent variations.

Contribution

It introduces a detailed analysis of salt ion effects on wetting films and bubble interactions near ice, incorporating Lifshitz and Casimir--Polder theories with different polarizability models.

Findings

Salt ions significantly affect water film thickness.

CO2 bubbles are attracted to ice-water interfaces.

Model choice impacts predicted film thickness.

Abstract

We study the effect of salts on the thickness of wetting films on melting ice and interactions acting on CO$_2$ bubble near ice-water and vapor-water interfaces. Governing mechanisms are the Lifshitz and the double-layer interactions in the respective three-layer geometries. We demonstrate that the latter depend on the Casimir--Polder interaction of the salt ions dissolved in water with the respective ice, vapour and CO$_2$ interfaces, as calculated using different models for their effective polarizability in water. Significant variation in the predicted thickness of the equilibrium water film is observed for different salt ions and when using different models for the ions' polarizabilities. We find that CO$_2$ bubbles are attracted towards ice-water interface and repelled from the vapor-water interface