Research On Preparation And Properties Of Rare Earth Magnesium Strontium Silicate Luminescent Material For Luminescent Fiber

The rare earth long afterglow luminescent material is an emerging functional material with the ability of absorbing and storing energy. After irradiated and excited by external light source, this kind of luminescent materials could emit colorful lights in the dark for hours. Due to their excellent properties such as non-polluting, non-radioactive, environment-friendly and outstanding afterglow characteristics, the aluminate luminescent materials have become a research hotspot since the1990s. The rare earth strontium aluminate luminescent fiber developed by our research group is an organic combination of rare earth luminescent materials and the traditional textile field. Compared to the aluminates, silicate luminescent materials have better chemical stability and water repellent ability, as well as lower calcination temperature and cheaper raw materials. Therefore the silicates has a broader space for development and application prospects.In this paper, the rare earth magnesium strontium silicate luminescent phosphor was synthesized via high temperature solid state reaction. By designing orthogonal experiment, the effects of calcination temperature, dosage of boric acid and Eu2+、Dy3+ions on phosphor’s properties were studied. Using test methods such as XRD and SEM, the optimum synthesis ratio was discovered. The results show that initial luminescent intensity of phosphor prepared by solid state method reaches2538mcd/m2, its persistence time lasts about1400s; the phosphor has phase of Sr2MgSi2O7only, its powder particles distribute in different sizes and irregular shapes.On the basis of solid state method, phosphor of Sr2MgSi2O7:Eu2+, Dy3+was prepared through sol-gel method while its phase structure, fluorescence spectroscopy, afterglow performance and surface morphology were characterized. Experimental results demonstrate that the sintering temperature of sol-gel method declines about150℃compared to solid state method; its initial luminescent intensity is up to1614mcd/m2and persistence time lasts about920s; its powder particles are composed of relatively regular shapes with particle diameter distribution in the range of3～5μm.The rare earth magnesium strontium silicate luminescent fiber (short for SMSED-PP luminescent fiber) was successfully synthesized through melt spinning method. Morphology, phase structure, spectral characteristics and afterglow features were tested and analyzed. The results indicates that SMSED-PP luminescent fiber has a superposition phase structure of both Sr2MgSi2O7:Eu2+, Dy3+and polypropylene; luminescent properties of this fiber mainly depends on the luminescent materials contained in the fiber, thus SMSED-PP luminescent fiber has the same luminescence spectra and afterglow decay curves of Sr2MgSi2O7:Eu2+, Dy3+; when the mass fraction of phosphors reaches15%, luminescent fiber has both good afterglow intensity and continuous spinnability.