Preparation And Luminesencent Properties Of Europium Complex And Its White Light Polymer

The white LEDs has received widespread attention owing to long life,high color rendering index, no pollution, and environmental friendliness. The phosphor converted white LEDs is mainstream, including two kinds of schemes, such as Blue Chip+Yellow phosphor and Near Ultraviolet Chip+trichromatic fluorescent powder. The latter with the high color rendering index and strong color reproduction has attracted much attention from the lighting manufacturers. The near-ultraviolet excitation yellow europium complex phosphor was synthesized using one-step process. And a bonding-type white copolymer phosphor was prepared employing the Eu-complex, green terbium complex and methyl methacrylate. The main results are as follows:(1) Reactive yellow europium complex was synthesized using2-(2-hydroxyphenyl) benzothiazole as the first ligand, 1,10-phenanthroline as the second ligand, undecylenic acid as active ligand. Its IR and UV spectra show that these three ligands have coordinated with Eu(III) ion. The fluorescence spectra show that the complex exhibits Eu(III) ion characteristicemission at 579, 597, 612, 652, 700 nm, and its color coordinates is X=0.418,Y=0.410, located in yellow light region.(2) A red-emitting Eu-containing copolymer phosphor represented by PM-Eu was prepared by solution copolymerization employing methyl methacrylate as polymer matrix and reactive yellow europium complex. Uv-vis spectra indicate that the ultraviolet light absorption of the coploymer PM-Eu is similar to europium complex. Fluorescence spectra show that the coploymer PM-Eu displays Eu(III) ion characteristic emission at 579,597, 612, 652, and 700 nm, and its color coordinates is X=0.515, Y=0.285,located in red light area. TGA show that the maximum thermal decomposition rate of PM-Eu is at 378? and thermal decomposition does not occur before266?, indicating that the coploymer PM-Eu has good thermal stability.(3) A bonding-type copolymer white phosphor was synthesized by solution copolymerization using reactive europium complex, reactive terbium complex and methyl methacrylate. Fluorescence spectra show that the copolymer exhibits blue, green, red tricolor characteristic emission at 411, 545,612 nm, respectively. The color coordinates is X=0.320, Y=0.331, which is located in the white light area. Thermal performance show that the initial thermal decomposition temperature of the copolymer is located about 250?,and the thermal decomposition temperature at the maximum rate is located at378?. The glass transition temperature of the coploymer is 134.9?. The color temperature of the white LED device made of the copolymer is 5690 K, colorrendering index is 78.3, and color coordinate is X=0.303, Y=0.334 being located in white light area. The above white fluorescent copolymer prepared in this study has potential application values for the near UV excited white LEDs.