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).
More Information:
Power Point Presentation
►Hydrophilic
Glass
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