Bonding Europium Complexes And Their Copolymers Synthesis And Performance

Due to the unique electronic structure, the rare earth complex becomes a new type of luminescent material with unique properties. It has potential applications in the areas of photoluminescence, electroluminescence, and polymer optical fiber. Rare-earth hybrid polymer has attracted wide attention because of the combinations of high luminous intensity, color purity of the rare-earth ions and excellent performance of processing molding of the polymers. In this paper, five bonded rare earth complexes were prepared. The relationships between fluorescence intensity of rare earth complexes and ligand structure as well as the synergistic effects of second ligand were studied. A series of rare earth hybrid polymers were obtained by the copolymerization of bonded rare earth complexes, methyl methacrylate (MMA) and methacrylate (HMA). With the change of type and concentration of rare earth complexes in copolymers, the properties of the copolymers were studied. The relationships between the concentration of rare earth complexes in the copolymers and the fluorescence intensity, absorbance and transmittance of copolymer are obtained analytically by regression analysis.The main results are summarized as follows:1 EuCl3.nH2O, Eu(AA)3, Eu(MA)3, EuCl3.Phen, Eu(AA)3.Phen, Eu(MA)3.Phen, Eu(acac)3, Eu(acac)2.AA and Eu(acac)3.Phen were prepared by the method of solution precipitation. The fluorescence intensities of the complexes were compared. The study on fluorescence spectrum shows that optimal excitation wavelength of EuCl3.nH2O, Eu(AA)3, Eu(MA)3, EuCl3.Phen, Eu(AA)3.Phen and Eu(MA)3.Phen is 396nm. Optimal excitation wavelength of Eu(acac)3, Eu(acac)2.AA and Eu(acac)3.Phen is 536nm. The fluorescence emission spectra intensity of binary rare earth complexes has the following relationship:Eu(acac)3＞EuCl3.Phen＞Eu(AA)3＞Eu(MA)3＞EuCl3.nH2O. Fluorescence intensities of binary rare earth complexes are higher than that of EuCl3.nH2O. They have the same emission characteristic wavelength. The fluorescence intensity of characteristic emission wavelength of ternary rare earth complexes has the following relationship:Eu(AA)3Phen>Eu(AA)3, Eu(MA)3Phen>Eu(MA)3, Eu(acac)3Phen> Eu(acac)3. It means that the introduction of 1,10-Phen can significantly improve the fluorescence intensity of rare earth complexes.2 A series of rare earth hybrid polymers were obtained by the copolymerization of bonded rare earth complexes, methyl methacrylate (MMA) and methacrylate (HMA). With the change of type and concentration of rare earth complexes in copolymers, the properties of the copolymers were studied. The copolymers emit the characteristic fluorescence of Eu3+. Under the same concentration of rare earth complexes, the copolymers of ternary complexes have stronger luminous intensity than that of the copolymers of binary complexes. However, under the condition of the maximum solubility, the copolymers of binary complexes have stronger luminous intensity than that of the copolymers of ternary complexes, which contributes to that the solubility of ternary complexes are less than that of binary complexes in the mixture solutions of MMA and HMA.The rare earth complexes and copolymers emit red light and it has well monochromatic.Compared to the rare earth complexes, the fluorescence intensities of copolymers are weaker because of the low concentration of rare earth complexes in the copolymers. Under the same concentration of rare earth complexes in copolymers, transmittance of copolymers of binary complexes is better than that of copolymers of ternary complexes and the absorbance of the latter is better than that of the former.With the increase of the concentration of Eu(AA)3 in copolymers, fluorescence intensity and absorbance increase monotonously. While their transmittance decrease. Copolymer has an absorption peak at 394nm and an absorption valley at 394nm.Water absorption of copolymers is lower than that of MMA-co-HMA under the condition of low concentration of Eu(AA)3. It increases with the increase of the content of Eu(AA)3. To some extent, the introduction of rare earth complexes in copolymers increases water absorption of copolymers. However, generally speaking, the water absorption of copolymers is somewhat low and the copolymers can be used as optical plastic.3 The relationships between the concentration of rare earth complexes in the copolymers and the fluorescence intensity, absorbance and transmittance of copolymer are obtained analytically by regression analysis. The results show that in copolymer Eu(AA)3-co-MMA-HMA, fluorescence intensity and absorbance of the copolymer increases linearly and transmittance decreases exponentially with the increase of Eu(AA)3 in copolymers.