A novel inorganic-organic nanocomposite film was prepared and characterized by IR, UV-Vis, XRD and DTA-TG. IR and UV-Vis spectra show that the Keggin structure of SiW 12O 4- 40 polyanion is preserved in the composite ...A novel inorganic-organic nanocomposite film was prepared and characterized by IR, UV-Vis, XRD and DTA-TG. IR and UV-Vis spectra show that the Keggin structure of SiW 12O 4- 40 polyanion is preserved in the composite film and there is an interaction between H 4SiW 12O 40 and the organic substrate. The composite film showed a reversible photochromism. Under UV irradiation, the composite film turns blue and charge transfer occurs by oxidation of R-NH + 3 and reduction of SiW 12O 4- 40. When the irradiated samples are placed in air and sheltered from the light, they change back to their original color, and recover again when being exposed to UV light.展开更多
Dendritic polyesters bearing COOH groups at the focal points were grafted onto nanometer silica premodified with 3-aminopropyltriethoxysilane by N,N′-dicyclohexylcarbodiimide mediated amidation. The products were cha...Dendritic polyesters bearing COOH groups at the focal points were grafted onto nanometer silica premodified with 3-aminopropyltriethoxysilane by N,N′-dicyclohexylcarbodiimide mediated amidation. The products were characterized qualitatively by FTIR, TGA and elemental analysis. It was shown that a significant grafting （10%15% net grafting for this reaction） was obtained despite the steric hindrance of the dendrons.展开更多
文摘A novel inorganic-organic nanocomposite film was prepared and characterized by IR, UV-Vis, XRD and DTA-TG. IR and UV-Vis spectra show that the Keggin structure of SiW 12O 4- 40 polyanion is preserved in the composite film and there is an interaction between H 4SiW 12O 40 and the organic substrate. The composite film showed a reversible photochromism. Under UV irradiation, the composite film turns blue and charge transfer occurs by oxidation of R-NH + 3 and reduction of SiW 12O 4- 40. When the irradiated samples are placed in air and sheltered from the light, they change back to their original color, and recover again when being exposed to UV light.
文摘Dendritic polyesters bearing COOH groups at the focal points were grafted onto nanometer silica premodified with 3-aminopropyltriethoxysilane by N,N′-dicyclohexylcarbodiimide mediated amidation. The products were characterized qualitatively by FTIR, TGA and elemental analysis. It was shown that a significant grafting （10%15% net grafting for this reaction） was obtained despite the steric hindrance of the dendrons.
