Hierarchically rough superhydrophobic metal surfaces fabricated by a sandblasting and hot water treatment process
Laylan B. Hassan, Nawzat S. Saadi, Tansel Karabacak
Abstract
Abstract This study proposes a cost-effective and scalable method of fabricating superhydrophobic surfaces on metallic materials by combining sandblasting (SB) and hot water treatment (HWT) to create hierarchical surface roughness. The method successfully produced superhydrophobic surfaces on aluminum alloy, copper, and zinc substrates, achieving contact angles (CAs) exceeding 150°. Micro-scale roughness was introduced via SB, while nano-scale roughness was induced by HWT, resulting in a dual-scale morphology crucial for enhanced hydrophobicity. The effects of varying SB abrasive sizes (60, 120, and 180 mesh) on surface morphology and wettability were thoroughly examined. Among these, 60-mesh abrasives generated the highest surface area and roughness. Post-fluorination, the hierarchically rough surfaces exhibited exceptional superhydrophobic properties, with CAs surpassing 160° and sliding angles (SAs) near 0°, demonstrating the lotus effect. Surfaces with only micro-roughness or nano-roughness resulted in intermediate CAs of 150–160° and SAs between 3 and 17°, underscoring the importance of hierarchical structuring.