Nanocoated glass cleans itself

Nanowerk News) Eyeglasses need never again to be cleaned, and dirty windscreens are a thing of the past! Researchers at the Max Planck Institute for Polymer Research in Mainz and the Technical University Darmstadt are now much closer to achieving this goal. They have used candle soot to produce a transparent superamphiphobic coating made of glass (

Doris Vollmer hates it that her eyeglasses always get dirty so quickly. However, the scientist, who heads a research group at the Max Planck Institute for Polymer Research, is looking for a solution to the problem - and she and her team are now a good deal closer to finding one. A transparent coating that is very good at repelling water and oil, as is now being presented by the Mainz-based researchers, could not only keep water and dirt away from the lenses in glasses and car windscreens, but also, for example, from the glass facades of skyscrapers. It could also prevent residues of blood or contaminated liquids on medical equipment.

A surface from which oil and water simply bounce off: The superamphiphobic coating is not even wet by the low-viscosity oil hexadecane, which would spread out even on a non-stick coating. Therefore, a drop of the liquid first bounces up off the surface before coming to rest on it as an almost perfect sphere. The superamphiphobic properties arise from the sponge-like glass structure that researchers at the Max Planck Institute for Polymer Research have developed. (© Science / Xu Deng – MPI for Polymer Research)

The coating essentially consists of an extremely simple material: silica, the main constituent of all glass. The researchers coated this with a fluorinated silicon compound, which already makes the surface water and oil repellent, like a non-stick frying pan. The really clever part is the structure of the coating, however. This is what makes the glass super water repellent and super oil repellent. In a frying pan with this type of coating, water and oil would simply roll around in the form of drops. The structure of the layer resembles a sponge-like labyrinth of completely unordered pores, which is made up of tiny spheres.