Anti-biofouling evaluation of vacuum-assisted hydrophobic ytterbium oxide (Yb2O3) coating on stainless steel by facile spray combustion

Abstract

Despite the development of numerous coating techniques and materials, today’s anti-biofouling applications require coatings that are facile and mechanically robust in nature. Studies on the hydrophobicity of rare-earth oxides have risen due to their unusual chemical properties; ytterbium oxide is one such oxide substance. In this study, spray combustion was used to create a hydrophobic coating of ytterbium oxide (Yb<inf>2</inf>O<inf>3</inf>) on a stainless steel (SS) substrate, which was then vacuum-treated. GI-XRD analysis confirmed the sesquioxide cubic crystalline structure of Yb<inf>2</inf>O<inf>3</inf>. FESEM images displayed an underneath wavy morphological coating with discrete particles on the surface. The thickness and roughness were ~12 and ~0.17 µm, respectively. When 5 and 10 N loads were applied, the coating showed better scratch hardness than uncoated SS. Water contact angle (WCA) <10° indicated superhydrophilicity in the fabricated coating. After vacuum treatment, it became hydrophobic, and the WCA was 128°; because of the increment in the relative area fraction of the C–H bond. The proportion of area covered by blue–green algae (Phormidium sp.) on vacuum-treated Yb<inf>2</inf>O<inf>3</inf> coating was only 3% compared to uncoated SS samples, 80%. © Indian Academy of Sciences 2024.