Fogging windows, windshields and glasses could be a thing of the past thanks to a breakthrough made by MIT scientists who have created a nanoparticle coating that causes water droplets to flatten into a thin uniform layer, instead of to form the usual fog in crystals that bothers so much.
According to the scientist Rubner, director of the team, “with our coating we are basically placing tiny glass particles on the surface, using a special layer-by-layer technique that we have developed. The result is a thin, nanoporous layer of glass on the surface that is hydrophilic.
Surfaces that are painted with this new material do not fog up and retain their transparency when exposed to moisture. This is very interesting for many optics that are in humid conditions. According to Rubner, “it could be applied anywhere where fog turns out to be a nuisance. The inside of the windshield, glasses, the bathroom mirror, double-layer windows…. ”
The covering is manufactured through the creation of alternating layers of a polymer called polyallylamine hydrochloride (in English) and silicon nanoparticles. According to Rubner, the scientists first immerse the substrate in a solution containing the polymer that spontaneously sticks to the surface. Then they rinse it with water and then put it in a solution that contains the glass nanoparticles. They perform the same cycle 10 to 20 times, to finish covering the surface. Finally, the glass substrate with the layer is heated up to 400 to 500 ° C to burn the polymer and make the coating more durable by fusing the silicon nanoparticles.