A Scalable Methodology for Reinstating the Superhydrophilicity of Ambient-Contaminant Compromised Surfaces

The degradation of the hemiwicking property of superhydrophilic high-energy surfaces due to contaminant adsorption from the ambient atmosphere is well-documented. This degradation compromises the performance of such surfaces, thus affecting their efficacy in real-world applications where hemiwicking is critical. In this work, the role of surface micro- and nanostructure morphology of laser-textured metallic surfaces on superhydrophilicity degradation is studied. We explore intrinsic contact angle variations of superhydrophilic surfaces via the adsorption of organics from the surroundings, which brings about the associated changes in surface chemistry. Furthermore, we explore condensation from humid air as a scalable and environmentally friendly methodology that can reinstate surface superhydrophilicity to a considerable extent (64% recovery of intrinsic wettability after 3 h of condensation) due to the efficient removal of physisorbed contaminants from the surface texture features. The present results strengthen the argument that contact-line movement at fine scales can be used for depinning and removal of adsorbed organic molecules from contaminated surfaces.