Author/Authors :
Minquan، نويسنده , , Wang and Guodong، نويسنده , , Qian and Mang، نويسنده , , Wang and Xianping، نويسنده , , Fan and Zhanglian، نويسنده , , Hong، نويسنده ,
Abstract :
The fluorescence properties of pyrene doped in silica xerogels by a sol-gel process and dissolved in ethanol in various concentrations were studied comparatively. With increasing gelation time the fluorescence spectra of pyrene doped in silica gels change greatly. Pyrene monomer excitation bands arise gradually with decreasing intensity of pyrene excimer excitation bands, which increases the intensity of the monomer emission and decreases that of the excimer emission. Compared with dissolving pyrene in ethanol, doping with pyrene in silica xerogels can increase the quenching concentration of pyrene enormously and thus increase the monomer fluorescence intensity of pyrene by a factor of approximately 20 with respect to that in ethanol solution. These changes can be explained by the modification of the pyrene surroundings. The pyrene molecules are isolated and absorbed in the tiny pores of the silica network steadily to avoid aggregate formation in silica xerogels.
