What is self-cleaning glass? Self-cleaning glass windows come with a really thin titanium dioxide coating which is applied to outer part of the glass. It does reduce the amount of light that passes through by a small margin.
The term 'hydrophilic' is referred to the process of self cleaning. It depends on the ultraviolet rays from the sun to stimulate the titanium dioxide coating on the glassware for a chemical reaction. This reaction breaks down the dirt and contaminants’ chemical properties into smaller movable substance for it to be easily washed away by rain.
Hydrophobic glass is another type of self clean glazing. The coating that covers it works to repel water in order to stop dirt and grime from sticking to the glass. Instead, the water forms into droplets or beads which rolls off the glass taking the contaminants that it picks up along the way, to leave a clear surface area.