Testing of the superhydrophobicity of a zinc oxide nanorod array coating on wood surface prepared by hydrothermal treatment

Natural wood surface is hydrophilic and can easily absorb moisture. Inorganic nanometer-scale metal oxides can be controlled and fabricated on wood surface to serve as a protective coating. In the present study, a superhydrophobic surface consisting of zinc oxide (ZnO) nanorod array was successfully attached on wood via a cosolvent hydrothermal method at low temperature. By means of X-ray diffraction pattern and Fourier transform infrared spectroscopy, the presence of the hexagonal wurtzite phase of ZnO was detected and characterized. Field-emission scanning electron microscopy showed uniform, large-scale rod-like ZnO crystal whiskers on the wood surface. The wettability of the wood surface after treatment became superhydrophobic, with a water contact angle of 153°. The prepared coating also showed an anti-contamination effect against milk, cola, soya sauces and coffee.