Medieval painted church windows were based on the principles of nanotechnology!

Washington, August 22 : Painting glass windows with gold nanoparticles offers a way to purify the air, say researchers.

Zhu Huai Yong, an associate professor at Queensland University of Technology's School of Physical and Chemical Sciences, highlights the fact that glaziers in medieval forges were the first nanotechnologists who produced colours with gold nanoparticles of different sizes.

The researcher says that numerous church windows across Europe were decorated with glass coloured in gold nanoparticles.

"For centuries people appreciated only the beautiful works of art, and long life of the colours, but little did they realise that these works of art are also, in modern language, photocatalytic air purifier with nanostructured gold catalyst," he says.

Zhu says that tiny particles of gold, when energised by the sun, can destroy air-borne pollutants like volatile organic chemical (VOCs), which may often come from new furniture, carpets and paint in good condition.

"These VOCs create that 'new' smell as they are slowly released from walls and furniture, but they, along with methanol and carbon monoxide, are not good for your health, even in small amounts," he says.

"Gold, when in very small particles, becomes very active under sunlight.

"The electromagnetic field of the sunlight can couple with the oscillations of the electrons in the gold particles and creates a resonance.

"The magnetic field on the surface of the gold nanoparticles can be enhanced by up to hundred times, which breaks apart the pollutant molecules in the air," he adds.

According to the researcher, the by-product will be carbon dioxide, which is comparatively safe, particularly in the small amounts that will be created through this process.

Zhu believes that the use of gold nanoparticles to drive chemical reactions may open up exciting possibilities for scientific research.

"This technology is solar-powered, and is very energy efficient, because only the particles of gold heat up," he says.

"In conventional chemical reactions, you heat up everything, which is a waste of energy.

"Once this technology can be applied to produce specialty chemicals at ambient temperature, it heralds significant changes in the economy and environmental impact of the chemical production," he adds.

ANI