[Effect of PEG400 on the luminescent Eu(BA)3/SiO2]

Rare earth organic complexes combined with inorganic compounds can enhanced thermal stability, but inorganic compounds matrix has great influence on the luminescence characteristic of rare earth organic complexes. The luminescence characteristic of organic and inorganic compound material was improved by PEG doping in the material. Eu(BA)3/SiO2 and Eu(BA)3/PEG400-SiO2 were synthesized by Sol-Gel method. The result of luminescence analysis showed that the excitation spectra and emission spectra of Eu(BA)3 accorded with those of Eu(BA)3/SiO2 and Eu(BA)3/PEG400-SiO2, but the luminescence intensity of Eu(BA)3/SiO2 was improved by PEG400-SiO2 in SiO2 gel. This was because PEG400 as a hard Lewis base, could be combined with rare earth ion and increase the luminescence intensity of Eu(BA)3. It was shown that the amount of PEG400 in Eu(BA)3/SiO2 had influence on luminescence intensity of Eu(BA)3, namely there was better luminescence intensity in Eu(BA)3/SiO2 with increment of the PEG400 addition, but when the amount of PEG400 exceeded 50 wt% of that of SiO2, the luminescence intensity of Eu(BA)3 hardly increased. When the amount of PEG400 exceed 15 wt% of that of SiO2, PEG400 had little influence on the content of water and hydroxy in the matrix, as verified by IR spectrum. The surface characteristic of SiO2 gel was investigated by atomic force microscopy (AFM).