Preparation of superhydrophobic films on copper substrate for corrosion protection

The carambola-like CuO film on copper substrate was hydrothermally synthesized using copper acetate and hexamethylenetetramine solutions at 90 °C. The CuO particles, which were composed of nanopetals with a thickness of 80 to 120 nm, had a shape similar to a carambola of 600 nm in width and 800 nm in lengths. The CuO film was endowed with superhydrophobic property by modifying with stearic acid (STA), which was referred to the STA-modified CuO film. The morphologies and chemical composition of the CuO film were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and means of water contact angle (WCA). The WCA of the STA-modified CuO film was measured to be as high as 157°. The corrosion resistance ability and durance property of the STA-modified CuO film in a 3.5 wt.% sodium chloride solution was evaluated by electrochemical impedance spectroscopy (EIS). Moreover, the anticorrosion properties of the STA-modified CuO film were compared with the unmodified pure copper substrate.