Was I out of the room when they came up with self-cleaning windows? According to Wikipedia, the first self-cleaning glass was available in 2001.
The secret ingredient it turns out is Titania (titanium dioxide). It’s become the material of choice for self-cleaning windows. Coated on windows, it does all it needs to do PLUS it’s non-toxic, chemically inert in the absence of light, inexpensive, and relatively easy to handle. PLUS it’s an “established household chemical used as a pigment in cosmetics and paint and as a food additive.”
Talk about a miracle in chemistry!
How does it work? In sunlight, the coating chemically breaks down organic dirt absorbed onto the window. When the glass is wet by rain or other water, something reduces the contact angles to very low values, causing the water to form a thin layer rather than droplets, and this layer washes dirt away. Can this really work?
Yes! An Ohio State University group of biochemists have succeeded in growing nano-scaled fibers on surfaces. The invisible fibers dramatically alter the properties of the surface on which they are grown, resulting in self-cleaning windows.
A leading brand is Pilkington, should you be redoing your windows.