Preparation And Characterization Of Organic Silicon Polymer Material And Their Europium Complexes

In this thesis, the development of rare earth theory, related new method, new technology, and the development of rare earth polymer complexes are fully described. Based on the current development and research in this field, we identified with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane(AEAPS) and silicon fluoride acrylic ester emulsion polymer as the ligands to synthesize the rare earth polymer complexes. The product has good thermal stability and excellent luminescence property.The main raw materials used to synthesize AEAPS-Eu(III) are AEAPS, citric acid and europium nitrate with the method of solution polymerization. During the reaction, amino functional groups in the AEAPS reacted with carboxylic acid groups in citric acid, and then there are some amide groups in the AEAPS. Amide groups have the role of chelating metal ions, so added europium nitrate to complex with the copolymer. A molecular of citric acid has three functional groups of carboxyl, which affects the property of the product. With the method of orthogonal experiment, the optimum synthesis conditions: temperature is 50 °C, the reaction time is 1 h, modification rate is 80 %, ratio of europium and citric acid is 1:1. 5. The resulted product without Eu(III) can emit bright blue light(440 nm) under near-UV light, and the optimal excitation wavelength is 365 nm. The AEAPS-Eu(III) showed colorful light under different excitation wavelength due to the red-shift of the emission from the polymer, and the emission from Eu(III) not changed meanwhile. The decay time of the emission from the Eu(III) is 0.495 ms. The thermal decomposition temperature is 370 °C, the glass transition temperature is 139 °C, which indicated the material has good thermal stability.Another kind of copolymer(SFA) was synthesized with methyl methacrylate(MMA), butyl acrylate(BA), γ-amino triethoxy silane(DB550), three fluorine propyl trimethyl silane(D3F), nonyl phenol polyoxyethylene ether(TX-10), hexadecyl trimethyl ammonium bromide(CTAB) and ammonium persulfate(APS), with the method of emulsion polymerization. The resulted copolymer is a kind of silicon fluorine modified acrylate emulsion, which containing amide bonds. The light-emitting principle is similar to the AEAPS-Eu(III).The effects of reactant ratio, the reaction temperature and rate of gel are studied through measuring the monomer conversion and performance of the copolymer to get the optimum proportion. The optimum synthesis conditions for the reaction: the temperature is 80 °C, the high shear time is 15 min, nonionic emulsifier TX-10 is 2 %, and the CTAB is 1.5 %, the APS is between 0.4 % and 0.8 %, the ratio of MMA and BA is about 2:1, silicon fluorine monomer is 25 %. The SFA:Eu(III) can emit red light(615 nm) under near-UV light, and optimal excitation wavelength is 395 nm, while SFA:Tb(III) emit yellow green(543 nm) under 378 nm. The SFA:Tb(III)/Eu(III) can only emit red light under 378 nm, which indicated that Tb(III) transfer energy to Eu(III). The thermal decomposition temperature of the SFA:Tb(III), SFA:Eu(III) and SFA:Tb(III)/Eu(III) are 300 °C, which indicated the material has good thermal stability. Infrared spectroscopy and thermal analysis are used to characterize the structure and properties of the copolymer. The luminescence properties of the two copolymers are characterized by PL, PL excitation spectra and PL decay curve.The results show that the two kinds of copolymer containing silicon europium complexes have good thermal stability and luminescence performance. All of these show that these two kinds of europium complexes can be used as a near ultraviolet excitation of white-LED luminescence reagent used for lighting and display.