Self Cleaning Glass- How does it work?

[ducatidd]

Just wondering if anyone has some good explanation on the technicalities behind it. I understand the basics of it, but wondering how the UV breaks down the dirt.
Thanks

 

[moltenmetal]

In theory the photocatalyst coating on the glass oxidizes grease and other organic filmy matter. If you wait long enough, organic matter will be oxidized away completely, but on exterior surfaces what probably matters more is that the partially oxidized materials are more soluble in rain water so they wash away more readily than the original film would have done. The photocatalyst will have no effect whatsoever on mineral grit (dust) etc.