A new photochromic complex of Keggin type Tungstophosphate acid/polyacrylamide system was prepared in aqueous solution, and its thin films was made by the dip coating technique. Their properties were investigated by F...A new photochromic complex of Keggin type Tungstophosphate acid/polyacrylamide system was prepared in aqueous solution, and its thin films was made by the dip coating technique. Their properties were investigated by FT IR, UV Vis, as well as TG DTA measurement. The results showed that this type of system had different properties in solution and in thin films. ESR spectra g values for the one electron blues were the characteristic of tetragonal W 5+ complex in aqueous solution and thin films. The formation of a radical signal of ESR spectra indicated that polyacrylamide was a proton donor, the reversibility for photochromism was relative to the presence and diffusion of oxygen in polymeric network.展开更多
A novel photochromic complex comprising of Keggin type tungstophosphate acid (PW12) and polyacrylamide (PAM) was prepared. FT-IR results showed that the Keggin geometry of PW12 was still preserved inside the composit...A novel photochromic complex comprising of Keggin type tungstophosphate acid (PW12) and polyacrylamide (PAM) was prepared. FT-IR results showed that the Keggin geometry of PW12 was still preserved inside the composite, and a charge-transfer bridge was built between PW12 and PAM via hydrogen bond. AFM images indicated that surface topography of polymer matrix changed after adding PW12. Under UV irradiation, the film was reduced photochemically to yield a blue species, which was reversible in the present of oxygen in polymeric network.展开更多
文摘A new photochromic complex of Keggin type Tungstophosphate acid/polyacrylamide system was prepared in aqueous solution, and its thin films was made by the dip coating technique. Their properties were investigated by FT IR, UV Vis, as well as TG DTA measurement. The results showed that this type of system had different properties in solution and in thin films. ESR spectra g values for the one electron blues were the characteristic of tetragonal W 5+ complex in aqueous solution and thin films. The formation of a radical signal of ESR spectra indicated that polyacrylamide was a proton donor, the reversibility for photochromism was relative to the presence and diffusion of oxygen in polymeric network.
基金This work was supported by the National Natural Science Foundation of China (59932040).
文摘A novel photochromic complex comprising of Keggin type tungstophosphate acid (PW12) and polyacrylamide (PAM) was prepared. FT-IR results showed that the Keggin geometry of PW12 was still preserved inside the composite, and a charge-transfer bridge was built between PW12 and PAM via hydrogen bond. AFM images indicated that surface topography of polymer matrix changed after adding PW12. Under UV irradiation, the film was reduced photochemically to yield a blue species, which was reversible in the present of oxygen in polymeric network.
