New “smart window” material can selectively filter light and heat

Researchers at the University of Texas developed a type of “filter” capable of blocking light and heat passing through the glass of a window. Called “dual-band electrochromic material”, the invention utilizes nanocrystals to block the passage of visible light by up to 80% and up to 90% of infrared light (which carries most of the heat).

“Dual band” refers to two types of nanocrystals present in the material, one that reduces the passage of visible light and another that does the same with infrared rays. “Electrochromic” means that you can switch between the light or heat blocking mode by activating a small electrical current. So when used in cold weather, this “smart” material can block the entry of light – which is sometimes reflected by the snow, for example – but let in the warmth of a sunny day.

With these “smart” windows, electricity consumption could be drastically reduced, because depending on the location, people could enjoy more hours of sunlight without necessarily facing the high temperatures that come with it. Delia Miliron, a chemical engineering professor at the University of Texas at Austin, published an article in the  Journal of the American Chemical Society describing the entire process of creating the material, and mentions that it already has the potential to be commercialized.



[Image source: ACS Publications]

It could be turned into an adhesive and applied directly to the glass of any window. With only one component – doped titania nanocrystals – it would be possible to switch the “smart window” from heat- to light-blocking mode with only a weak electrical current in minutes.

Source: Journal of the American Chemical Society