Superhydrophobic or superhydrophilic surfaces regulated by micro-nano structured ZnO powders

The present study demonstrates a simple technique to decorate a surface for superhydrophobic or superhydrophilic properties by randomly coating an inorganic oxides powder. The superior properties are stable in air for more than half a year. The particulates of the powder are made from aligned single crystalline ZnO nanorods, which aggregate to microspheres with image ends pointed outside of the spheres. The density of surface hydroxyls of ZnO nanorods and the micro-nanostructures of the particulates are responsible for their superior properties.