Coloration
efficiency and a fast response are important in developing
materials for optical switching. A novel, highly efficient photochromic
tungsten oxide@poly(N-isopropylacrylamide) (PNIPAM)
hybrid sphere is reported, whose colors can be rapidly converted between
yellow and blue under different lights. The color change can be seen
clearly even if the tungsten oxide content in the hybrid sphere is
very low, exhibiting outstanding coloration efficiency of tungsten
oxide. A photochromic mechanism is proposed in which the amide group
in PNIPAM spheres participates in electron injection and the transition
of valence states between W5+ and W6+ in the
photochromic process. The interaction between tungsten oxide and PNIPAM
plays a key role in enhancing the coloration efficiency of tungsten
oxide and accelerating the switchable speed of color transformation,
which is very useful in developing new photochromic materials. These
hybrid spheres can be used in rewritable record displays and have
wide potential applications in controlling energy transmittance in
smart windows or in detecting UV light in optical sensors.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.