No abstract

The recycling luminous materials SrAl2O4:Eu2+, Dy3+ is a kind of long afterglow phosphor, prepared based on the alcoholysis of luminous polyester fabric, which has excellent characteristics like high lightness and long afterglow time. However, for that the luminous materials SrAl2O4:Eu2+, Dy3+ are recycling, and the process on the alcoholysis of luminous polyester fabric may affect its performance. Hence, in this study a couple of luminous materials SrAl2O4:Eu2+, Dy3+ were recycled from luminous polyester fabric based on the method of alcoholysis, the phase structure and luminescent properties of the fibers were characterized by scanning electron microscopy (SEM), x-ray diffractometer (XRD), fluorescence spectrometer and afterglow luminance meter. The results deduced that under a certain condition, the luminous polyester fabric can be basically degraded, and the recovered luminescent materials can be obtained at a high purity. Our research supplies a strategy to recycle luminous phosphors as well as other functional materials, and hopefully it could inspire development for luminous materials and fibers.

No abstract

Composite red luminescent material SMED/LCA (Sr2MgSi2O7:Eu2+,Dy3+/light conversion agent) is a phosphor with long afterglow, which was prepared by LCA and SMED at a certain mass ratio. It has excellent characteristics, such as high lightness and emitting red light, but poor stability properties because LCA falls off easily from the surface of SMED. Here, SiO2 (Al2O3 or MgF2) was coated on the surface of SMED/LCA through the heterogeneous deposition method to prepare a stable composite phosphor, adding coated phosphor into a polyacrylonitrile (PAN) fiber-forming polymer and wet spinning to form SMED/LCA-PAN (composite red light-emitting fiber). The surface element distribution, phase structure and luminescence properties of SMED/LCA-PAN were characterized. The results show that SiO2 (Al2O3 or MgF2) is successfully coated on the surface of the material, and the coating has no effect on the phase of SMED in the fibers. The intensity red/blue ratio (Int.600 nm versus Int.470 nm) of coated SMED/LCA fiber in the afterglow emission spectrum increases by about 1.9 times; the increase in energy conversion efficiency indicates the enhancement of the red light effect. In addition, the afterglow initial brightness is up to 0.148 cd/m2 after 15 min of ultraviolet light excitation, and the luminous fiber still has high afterglow brightness.

In order to improve the red luminous properties of luminescent fibers, Sr2MgSi2O7:Eu2+, Dy3+ and light conversion agents were treated with silane (KH560), aluminate (DL-411-A), and aluminum zirconium coupling agents (LD-139-3) to prepare composite luminescent materials. And then they were added to a polyacrylonitrile (PAN) fiber-forming polymer and through wet spun to form composite red light-emitting fibers. The surface morphology, phase structure, and luminescence properties of the composite red light-emitting fibers were characterized by scanning electron microscopy, X-ray diffraction, fluorescence spectrometry, and afterglow brightness tester. Results showed that all of the three kinds of coupling agents influenced the red light of the luminescent fibers. The aluminate ester coupling agent had more effect than that of the other two coupling agents. After treatment with the aluminate coupling agent, the surface of the luminescent material became rough and adhered to the particles of light conversion agent. The intensity of the emission peak of the luminescent fibers at 470 nm decreased, and the emission peak intensity at 595 nm improved. The initial afterglow brightness and afterglow duration remained unchanged after 15 min of ultraviolet light excitation, as well as the color purity increased by approximately 1.6 times.