Hydrophilic Glass

The latest in glass technology are “self-cleaning” and “low-maintenance” window glass, two categories which encompass window glass products that are coated or fused with titanium dioxide (TiO₂) alone or with under-layers or silicon dioxide (SiO₂). 

Hydrophilicity – This term describes the property of a surface that makes it have an affinity for water. When water hits hydrophilic glass, it flattens and spreads out to form a thin sheet on the glass surface. This sheeting action not only helps rinse away loosened dirt and other organic material it also minimizes spots and streaks by helping the glass dry more quickly and evenly.

A glass surface is considered to be hydrophilic if the contact angle of a water bead on its surface is less than 20 degrees. In contrast, a hydrophobic surface (which promotes beading like that of a freshly waxed automobile) has a contact angle of more than 60 degrees. The contact angle on ordinary glass measures 20-40 degrees.

Photocatalysis – This term describes the property of a surface which allows it to decompose organic material. On a self-cleaning window, the surface of the glass will help break down loose dirt and other organic material. This allows the sheeting action of the water to more easily rinse loosened dirt away. This property also helps the glass maintain its hydrophilicity (ability to sheet water).

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   ►Hydrophilic Glass