BUFFALO, N.Y. — New materials science research from the University at Buffalo could hasten the creation of “smart” windows that reflect heat from the sun on hot summer days but let in the heat in colder weather.
The findings concern a unique class of synthetic chemical compounds that are transparent to infrared light at lower temperatures, but undergo a phase transition to begin reflecting infrared when they heat up past a certain point.
An article detailing some of these discoveries appears today (April 7) on the cover of the Journal of Physical Chemistry Letters. Additional papers have appeared online or in print in CrystEngComm, the Journal of Materials Chemistry and Physical Review B. The research is described in a video at http://pubs.acs.org/page/jpclcd/banerjee-video.html
In the papers, UB researchers report that they have managed to manipulate the trigger temperature for vanadium oxide, one such material. The advance is a crucial step toward making the compound useful for applications such as coatings for energy-saving windows.
By preparing vanadium oxide as a nanomaterial instead of in bulk, the scientists managed to lower the compound’s trigger point from 153 degrees Fahrenheit to 90. Doping vanadium oxide nanowires with tungsten brought the temperature down further, to 7 degrees Fahrenheit. Molybdenum doping had a similar but smaller effect.