Fabrication of nonaging superhydrophobic surfaces by packing flowerlike hematite particles

The authors demonstrate the fabrication of nonaging superhydrophobic surfaces by packing flowerlike micrometer-sized hematite (alpha-Fe2O3) particles. Although hematite is intrinsically hydrophilic, the nanometer-sized protrusions on the particles form textures with overhanging structures that prevent water from entering into the textures and induce a macroscopic superhydrophobic phenomenon. These superhydrophobic surfaces do not age even in extremely oxidative environments-they retain the superhydrophobicity after being stored in ambient laboratory air for 4 months, heated to 800 degrees C in air for 10 h, and exposed to ultraviolet ozone for 10 h. (C) 2007 American Institute of Physics.