Comparison of the fluorescence hybrid materials synthesized by two different methods

Europium ternary complex of Eu(NNA)3·phen (NNA=α-naphthylacetic acid and phen=1,10-phenanthroline) was incorporated in silica matrix with different ratios by sol-gel and impregnation method. The luminescence properties of silica composites and the corresponding pure complex were studied through fluorescence spectra and lifetimes. The results indicate that hybrid composites show fewer emission lines and lower fluorescence intensity than that of the pure complex. The fluorescent relative intensity and lifetime of the composite prepared through impregnation method is lower than that prepared by sol-gel method. The fluorescence lifetime was prolonged when the pure complex was incorporated in silica matrix through sol-gel method, but it was shortened when the impregnation method was used.