Liquid film thinning-thickening anomaly in electrolyte solutions

Unlike the common cases of continuous film drainage behaviors, the film thickness at the rim exhibits a counterintuitive increase, causing the previously approaching bubble to retract from solid surfaces. It is revealed how the inward flow can surpass the drainage outflow and reverse the normal film evolution. Theoretical developments involving the electrolyte type, ion concentration and film deformation are provided to describe this competition and address the film thinning-thickening anomaly. Our finding enriches the understanding of the microscopic fluid flow in highly confined and deformed regions, and the research outcome creates the possibility of modulating near-wall bubble dynamics as required.