For some time, rare earth oxides have been thought to be water-repellent. This march, scientists from the University of Basel, the Swiss Nanoscience Institute and the Paul Scherrer Institute, have found the real origin of this behaviour. They’ve shown that rare earth oxides do not present any significant hydrophobicity. Only when exposed to environmental conditions, they repel water. The explanation, it was only chemical reactions with gaseous hydrocarbons found in the ambient air that increased the surfaces’ roughness and reduced wetting by water.
Personally interested in the subject, we did this picture for them, advised by Dr. Laurent Marot.