August 23, 2008

Stained Glass as Nanotechnology??

Articles originating out of Queensland, Australia with titles like Gold nanoparticles purified air in old churches and Solar-Powered Nanotech-Purified Air In Medieval Churches and Stained glass windows painted with gold 'purify air' are hitting the news and blog sites for the past few days.

As much as I would like to see stained glass associated a with cool-sounding 'green'-oriented 21st century technology, I'm skeptical.

The glaziers who created gold-painted stained glass windows for medieval churches in Europe inadvertently developed a solar-powered nanotech air-purification system. According to Zhu Huai Yong, an associate professor at Queensland University of Technology in Australia, the gold paint used in medieval-era stained glass windows purified the air when heated by sunlight.

"For centuries people appreciated only the beautiful works of art, and long life of the colors, but little did they realize that these works of art are also, in modern language, photocatalytic air purifier with nanostructured gold catalyst," said Zhu in a statement.
Zhu said that tiny gold particles found in medieval gold paint react with sunlight to destroy air-borne pollutants like volatile organic chemicals/compounds (VOCs), which are emitted from paints, lacquers, and glues, among other things.

I won't pretend to even begin to comprehend the science behind this but there are some basic questions that come to mind. What are they talking about as the 'gold paint' in Medieval stained glass windows? Gold in the fired in paint? Gold in the glass itself? I've never heard of there being gold in stained glass paint, other than the rare occasional use of ruby enamel, which I always thought came into existence later than Medieval times. There is of course actual gold in pink glass - it's even called gold pink glass, but again that is rare and that would not be referred to as 'gold paint'. If there is a suggestion that gold was a trace element in fired in black paint in Medieval churches, it's news to me. Very puzzling.

It's a nice idea that stained glass has some hidden scientific or environmental benefit. I just want them to get the facts right.

Posted by Tom at August 23, 2008 12:52 PM