Preparation And Investigation Of Dye Composite Fluorescence Material

Aiming to improve the performance of phosphors be used in white LED, we prepared two kinds of nano-phosphor. We prepared fluorescent dye-h-Si O2 nanoparticles by reverse microemulsion and fluorescent PS microballon by emulsion polymerization respectively. And combine the fluorescent dye with PS microballon by bonding. Then composite dye nanoparticles were dispersed to epoxy resin, and both Both fluorescence properties and highly transparent nanocomposite functional flakes were obtained.In the second chapter, we prepared the dye-h-Si O2 nanoparticles by reverse microemulsion method. The excitation position of this material is at 460 nm. This material can simultaneously emit yellow-green and red light simultaneously, and could be applied to the blue light excitation remote LED lights. The scanning electron microscopy(SEM) images of the Ru(bpy)-h-Si O2 nanoparticles indicate the diameter of the dye-h-Si O2 nanoparticles is 65 ± 3 nm. The functionalized NPs were dispersed very well in aqueous solution, and no aggregation was observed due to the electrostatic repulsion force between the NPs. Many disorderly holes could be found in the Si O2 NPs and the dye is dwelling in these holes steadily. The silica layer is a good shield against oxygen and moisture, so that the dye-h-SMs could maintain their initial luminescence after high-power UV radiation and the 150 ?C LED encapsulant curing process. Through absorption matching of free dye and particle solutions, we determined the intensity of luminescence emission of Ru(bpy)32+ and FITC in our silica particles versus free dye in aqueous solution as 2.4 and 1.6, respectively. The dye-SMs were molded as a disk with a diameter of 4 mm and placed on the LED chip. The transparency of the dye-h-SMs decreases with the increasing dye-h-Si O2 doping content, but the dye-h-SMs still maintain a highly transparent in the visible range. The adjustable white light and highly color-saturated remote-phosphor LED could be realized by adjusting the ratio of green dye and red dye.In the third chapter, the fluorescent polymer nanoparticles were prepared through the combination of the dye and PS using a bonging method. And the fluorescent polymer nanoparticles were monodisperse spherical structure, with the particle size about 400 nm. There was no agglomeration. There were solid bond between the dye and the PS and the dyes. The fluorescent polymer is relatively stable and the dye leakage could be completely suppressed. The utilization of the dye has been maintained a high value by the bonding preparation process, indicating that PS has effectively combined with the dye. When the mass of the fluorescent lost 5%, the temperature was in the range of 329-335°C, which satisfied the white LED application conditions. The red and green organic fluorescent dyes and blue LED chips were chosen in this investigation. The excitation spectra of the dye polymers were at 460 nm and the emission peaks of Ru(bpy)3 and FITC were at 520 nm and 610 nm, respectively. As the colorimetric principles, the three primary colors can exhibit different colors by superposition of different proportions. The fluorescent polymer slice owns a high transparency and from the visible to the infrared range, the transparency of the dye sheet is more than 82%. We made the fluorescent polymer nanoparticles disperse in an epoxy and obtained the sheet with thickness of 4nm. It can apply in blue light LED. By testing the emission spectrum of the white LED as we prepared, we obtain that the color coordinates in 1931 were(0.30,0.31), which indicated the use of such green and red dyes could be prepared to emit the appropriate white light and it owned a remote excitation LED with high color saturation.