Thermal Stability of Typical Superhydrophobic Surfaces

Two kinds of typical superhydrophobic surfaces, ZnO nanorods and porous nano-SiO2 coating were successfully prepared on nickel alloy plates using a wet chemical method for the ZnO nanorods and spraying for the nano-SiO2 coating. Thermal stability of each of the superhydrophobic surfaces was tested. Scanning Electron Microscopy (SEM) and energy dispersive spectrometry were used to analyze microstructures and compositions. Although both superhydrophobic surfaces show similar wettability with respect to water, the SiO2 Nanoparticles Superhydrophobic Coatings (SiO2-NSCs) has better thermal stability than the ZnO Nanorods Superhydrophobic Coatings (ZnO-NSCs). The micro/nano structures of the two superhydrophobic surfaces can be destroyed during icing-melting cycles. In addition, at high temperature, the superhydrophobic properties of the surface can be destroyed because of the decomposition of fluorinated silane. The results can provide guidance for the practical cryogenic application of superhydrophobic surfaces.