Super-hydrophobic property of nano-sized cupric oxide films

Nano-sized cupric oxide (CuO) films with biomimetic super-hydrophobic surfaces were fabricated by isothermally oxidizing nano-sized Cu films prepared by electroless plating on smooth glass substrate following modification with octadecanethiol (CH3–(CH2)17–SH). The microstructure characterization showed that CuO films with 54 nm thickness have a dual-scale structure consisting of the 150–200 nm agglomerates composed of the 30–50 nm granules, a similar structure to lotus-leaf. The measurement of wettability showed that CuO films modified with octadecanethiol exhibit a super-hydrophobic property with a water contact angle of ~ 154°. The mechanism leading to the super-hydrophobic property of CuO films was also analyzed based on the results of X-ray photoelectron spectroscopy (XPS).