At the flick of a switch “Smart Window” allows user to regulate the light passage. One could enhance energy efficiency of a building or could use as an image projection screen. The applications of “Smart Window” technology are numerous including recently produced new Boeing 787 Dreamliner. Over the years various types of technologies have been tried including photochromic, thermotropic, suspended particle devices (SPDs), polymer dispersed liquid crystals devices (PDLCs) or micro-blinds. All of these technologies have advantages as well as disadvantages.
Recently, scientists from Republic of Korea reported a different kind of nanotechnology based platform for “Smart Windows” which could become a game changer. They developed polymeric counter-anions which have different hydration energies. When spray casted over a glass substrate, it can alternate between extreme optical characteristics. In other words, coated glass could change from opaque to a clear one instantaneously. The immediate application: reduces the amount of heat loss in winter or increases the cooling in summer. This work has been reported in the journal ACS NANO.
[Ref: C.H. Lee, H.S. Lim, J. Kim, and J.H. Cho; ACS NANO; 5 (9), pp. 7397-7403 (2011); DOI: 10.1021/nn202328y]
Further reading: http://en.wikipedia.org/wiki/Smart_glass
