Direct Fabrication of Super hydrophobic Ceramic Surfaces with ZnO Nanowires

Super-hydrophobic surfaces having contact angles > 150◦ for water are of great interest due to their potential use in a wide variety of applications. Although many reports on the wettability of different surfaces have been published, few or no studies have been done on the formation of a super-hydrophobic surface on a ceramic substrate. In this paper, we demonstrate the creation of a super-hydrophobic surface on a ceramic substrate by using zinc oxide nanowires (ZnO NWs) prepared by using a direct hydrothermal method. A self-assembled monolayer of heptadecafluoro- 1,1,2,2-tetrahydrodecyl trichlorosilane (HDFS) lowered the surface energy between the water droplet and the nano-textured surface. The length of the ZnO NWs was found to play a key role in the formation of a nanostructure that increased the surface roughness of the substrate. Furthermore, the length of the ZnO NWs could be controlled by changing the growth time, and HDFS-coated ZnO NWs were found to be super-hydrophobic after a growth time of 3 h. We have demonstrated the potential application of this nanostructure for ceramic tableware by introducing a ZnO-NW textured surface on a ceramic cup, which resulted in water and alcohol repellency. This method is a simple and practical way to achieve a super-hydrophobic surface; hence, our method is expected to be widely used in various ceramic applications.