Wettability Investigation of Laser-Crafted Antiwetting/Superwetting Surfaces on a Polyethylene-Painted Aluminum Plate for Moisture Management

The heightened atmospheric humidity from sea warming poses concerns about infrastructural damage and residential discomfort. It has motivated extensive surface engineering research on antiwetting and dehumidification. However, the preparation of large-scale surfaces incorporating promising dual antiwetting/superwetting features with high efficiency and sustainability is challenging due to procedural complexity and limited industrialization. This study introduces a straightforward laser etching approach independent of chemical inputs and complicated experimental variables for crafting superior wetting surfaces on a commercially available aluminum plate applied to a surface-engineered architecture to combat the exacerbated moist ambient. Outstanding isotropic superhydrophobicity (water static contact angle (WCA) = 162.81 ± 2.26°, water sliding angle (WSA) = 6.06 ± 0.44°) and superhydrophilicity (WCA ≈ 0°) were achieved by controlling machine parameters and precisely manipulating the laser beam energy. Mechanism investigations, including a surface tension increase on interfacial hydrophilization and correlations between surface roughness and apparent contact angles, were thoroughly analyzed to figure out the essential influential factors in optimizing antiwetting or superwetting properties and to identify the dominant cause for wettability reversal. It was proved that the surface tension increase helps break through energy barriers between two opposite wetting behaviors, and surface roughness evolution governs wettability regulation in superhydrophobicity and superhydrophilicity following Cassie-Baxter's propositions and Wenzel's propositions, respectively. Additionally, superhydrophobicity isotropy examination, antiwetting/dehumidifying capability evaluation under humid circumstances contacting different phases of water, fractal-patterned moisture-capturing system design for room dehumidification, and environment/human impact and cost-efficiency assessment as alternatives to conventional approaches were comprehensively carried out. Our work underlines the technological versatility in customizing and integrating distinct wetting characteristics on identical carriers and its one-step fabrication advantage for large-scale production, offering significant practicability and promise for industrialization in moisture management surface engineering.