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 series of tungstophosphate, tungstosilicate acid/polyvinyl alcohol complexs were prepared. Their properties were investigated by IR, UV, TG-DTA and conductivity measurement.The results showed that heteropolyacid had...A series of tungstophosphate, tungstosilicate acid/polyvinyl alcohol complexs were prepared. Their properties were investigated by IR, UV, TG-DTA and conductivity measurement.The results showed that heteropolyacid had different photochromic properties in solution and thin films. The complexes thin films were proton conductors. Their conductivities increased when relative humidity increased and decreased when photochromism occurred in the thin films.展开更多
A new photochromic complex of Keggin type tungstophosphate acid/polyvinyl pyrrolidone system was prepared, and its thin films was made by the dipping method. Their photochromic properties were investigated by FTIR, UV...A new photochromic complex of Keggin type tungstophosphate acid/polyvinyl pyrrolidone system was prepared, and its thin films was made by the dipping method. Their photochromic properties were investigated by FTIR, UV Vis spectra. The salts were formed by the combination of the ion based on the N atoms in the polymeric molecules and H + of the acids. The UV Vis spectra showed that this type of system had an excellent photochromic behavior. The g values of ESR spectra for the one electron blues were the characteristic of tetragonal W(Ⅴ) complex in colored thin film. It was indicated that the charge could be transferred between the anion and cation under irradiation of UV light and the result in the oxidation of the cation and the reduction of the anion.展开更多
A kind of Keggin structural 12-WP acid was prepared and used as catalyst to synthesize methyl tert-butyl ether(MTBE) from methanol and tert-butanol.The influences of the amount of 12-WP acid,the ratio of reactants and...A kind of Keggin structural 12-WP acid was prepared and used as catalyst to synthesize methyl tert-butyl ether(MTBE) from methanol and tert-butanol.The influences of the amount of 12-WP acid,the ratio of reactants and reaction temperature on the yield of MTBE were investigated.The results showed that the conversion of tert-butanol,selectivity of MTBE and the yield of MTBE could be up to 59.6%,74.5% and 44.4%,respectively when the amount of 12-WP acid was 2.16% of tert-butanol and the mole ratio of tert-butanol to methanol was 1:1.2 at 100 ℃.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.
文摘A series of tungstophosphate, tungstosilicate acid/polyvinyl alcohol complexs were prepared. Their properties were investigated by IR, UV, TG-DTA and conductivity measurement.The results showed that heteropolyacid had different photochromic properties in solution and thin films. The complexes thin films were proton conductors. Their conductivities increased when relative humidity increased and decreased when photochromism occurred in the thin films.
文摘A new photochromic complex of Keggin type tungstophosphate acid/polyvinyl pyrrolidone system was prepared, and its thin films was made by the dipping method. Their photochromic properties were investigated by FTIR, UV Vis spectra. The salts were formed by the combination of the ion based on the N atoms in the polymeric molecules and H + of the acids. The UV Vis spectra showed that this type of system had an excellent photochromic behavior. The g values of ESR spectra for the one electron blues were the characteristic of tetragonal W(Ⅴ) complex in colored thin film. It was indicated that the charge could be transferred between the anion and cation under irradiation of UV light and the result in the oxidation of the cation and the reduction of the anion.
文摘A kind of Keggin structural 12-WP acid was prepared and used as catalyst to synthesize methyl tert-butyl ether(MTBE) from methanol and tert-butanol.The influences of the amount of 12-WP acid,the ratio of reactants and reaction temperature on the yield of MTBE were investigated.The results showed that the conversion of tert-butanol,selectivity of MTBE and the yield of MTBE could be up to 59.6%,74.5% and 44.4%,respectively when the amount of 12-WP acid was 2.16% of tert-butanol and the mole ratio of tert-butanol to methanol was 1:1.2 at 100 ℃.
