Abstract:

The long afterglow luminescent material of SrAl2O4∶Eu2+,Dy3+ was encapsulated with polystyrene foamed plastic via a simple physical technology, and charaeterized by means of X-ray diffraction patterns, fourier transform infrared spectroscopy, excitation and emission spectra, thermogravimetric analysis， and transmission electron microscopy observation. Its water durability was investigated. The results show that the encapsulated layer has a thickness of about 5~10 nm and the mass fraction of encapsulation amount is about 4.9%. The encapsulation does not change the inner structure of the phosphor and has barely influence on their photoluminescence. The encapsulation can effectively improve the water durability of the phosphors with initial intensity of 5.02 cd/m2. The decay time can reach up to over 10 h after immersed in water for 15 h.

Key words: afterglow, encapsulation, foamed plastic, SrAl2O4:Eu2+, Dy3+