Self-assembled biomimetic superhydrophobic CaCO ₃ coating inspired from fouling mineralization in geothermal water

Inspired from fouling self-mineralization in geothermal water, a novel biomimetic cactuslike CaCO ₃ coating with superhydrophobic features is reported in this letter. The structure, morphologies, and phases of the CaCO ₃ coating were characterized by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy, and infrared spectrophotometry. After prenucleation treatment, a continuous cactuslike CaCO ₃ coating with hierarchical nano- and microstructures was self-assembled on stainless steel surfaces after immersion in simulated geothermal water at 50 °C for 48 h. After being modified with a low-surface-energy monolayer of sodium stearate, the as-prepared coating exhibited superhydrophobic properties with a water contact angle of 158.9° and a sliding angle of 2°. Therefore, this work might open up a new application field of geothermal resources and provide insight into designing multidimensional structures with functional applications, including superhydrophobic surfaces.