Adsorption at Interfaces and Contact Lines: From Molecular Oversolubility to Macroscopic Wetting

Interfaces between two phases and contact lines between three phases are the locus of complex phenomena that govern the thermodynamic and dynamic behavior of such systems─both at the microscopic and macroscopic scales. Yet, despite the abundant literature on the topic, the impact of molecular adsorption at these phase boundaries remains only partially elucidated, with striking examples involving wetting/dewetting, fluid separation and capture, chemical reactions and catalysis, etc. Here, we shed light on the fundamental mechanisms that govern gas adsorption at interfaces and contact lines. By adopting a multiscale viewpoint, we offer perspectives on the role of this phenomenon in mechanisms ranging from molecular oversolubility at such boundaries to macroscopic wetting and transport of fluids at surfaces. Finally, this Perspective highlights future prospects and emerging opportunities to unravel and harness all the complexity of adsorption processes at interfaces and contact lines.