Water-repellent materials have a wide range of applications, but many hydrophobic coatings cannot withstand harsh conditions. Now, researchers at the Massachusetts Institute of Technology, Cambridge, report the production, from rare-earth oxides, of ceramic materials that remain hydrophobic even after exposure to harsh environments.

Kripa Varanasi and his colleagues synthesized ceramics from the lanthanide oxide series, including cerium oxide. In analysing the surface chemistry of the ceramics, the researchers found that the oxides' electronic structure inhibits hydrogen bonding with water molecules. They show that water droplets bounce off a cerium oxide surface (pictured), leaving the surface dry. Moreover, the ceramics maintain their hydrophobic nature even after abrasion and exposure to high temperatures.

Nature Mater. http://dx.doi.org/10.1038/nmat3545 (2013)