Study On The Co-luminescence And Preparation Of Rare Earth Nanomaterials By Phase Transfer Method

Rare earth elements were praised as"the vitamin of modern industry", and many rare earth complexes of different valences and coordination number(3～12) have been prepared , which were of good optical,electric,magnetic properties arising from their many unpaired electrons,high atomic magnetic moment and rich electronic energy levels. Rare earth materials of nano structure were of new properties, such as small size effect,high specific surface,quantum effect,superconductivity, and have been extensively applied in a variety of different areas including luminescent materials,crystal materials,magnetic materials,battery materials,electronic ceramics,engineering ceramics,and catalysts et al. The content of this paper consist of four parts as follows:1. The fluorescence enhancement mechanism of Dy³⁺-SSA system by adding Gd³⁺ was studied by the resonance light scattering and fluorescence spectrum. In this paper, the influencing factors including the concentration of Gd³⁺,SSA, pH value as well as surfactants were studied. As a result, the fluorescence and scattering-light intensity of the system Dy³⁺-Gd³⁺-SSA was increased by the surfactant CTMAB, and the optimal experimental conditions were Gd³⁺3.0×10^-4 mol·L^-1,SSA 2.0×10^-3 mol·L^-1,pH 8.0.2. The fluorescence quenching mechanism of Sm³⁺-TFA-TOPO system was studied in the presence of La3+. Resonance scattering-light spectrum indicated that there were three factors: the destroying of micelle, the competition of ligand and the form of new congeries. It analyzed the influence of scattering-light and fluorescence which was caused by different conditions. Then the optimal experimental conditions were studied. Without of La³⁺, the optimal experimental conditions of Sm³⁺-TFA-TOPO system were Sm³⁺ 2.0×10-5 mol·L^-1, TFA 2.0×10-4 mol·L^-1, TOPO 1.5×10^-4 mol·L^-1, pH=6.4 respectively. In the presence of La³⁺, The fluorescence intensity of the Sm³⁺-TFA-TOPO system was maximal on the optimal experimental conditions of Sm³⁺ 2.0×10^-5 mol·L^-1, TFA 3.0×10^-4 mol·L^-1, TOPO 1.5×10^-4 mol·L^-1, pH=5.8.3. Samarium sulfide of nano structure was prepared successfully. Sm³⁺ was transferred from water phase to organic phase by the term of the phase transfer agent of TTA,phen and the solubilizer of DMF, and the samarium sulfide of nano structure developed when the TAA was added as source of S2-. The preparation of nano-particles was characterized by transmission electron microscopy (TEM) and UV-vis spectroscopy,fluorescence and scattering-light spectroscopy. With the aim to attain better samarium sulfide nanoparticles, all kinds of factors were studied. The particle size of samarium sulfide nanoparticles was 40⁵0 nm or so, more uniform, character stability. The optimum conditions was: cSm:cTTA:cphen=1:7.5:1.25, Vorganic phase:Vwater phase =2:1; the optimum pH of the complex and the nanoparticles preparation was 5.46 and 6.27, respectively; the optimum time of phase transferring and nanoparticle generation process was 45 min and 60 min.4. Europium sulfide of nano structure was prepared by the same method as samarium sulfide of nano structure. The preparation of nano-particles was characterized by transmission electron microscopy (TEM) and UV-vis spectroscopy,fluorescence and scattering-light spectroscopy. The particle size of europium sulfide nanoparticles was 50 nm or so, the distribution was dispersed. The optimum conditions was: cEu:cTTA:cphen=1:2.7:1, Vorganic phase:Vwater phase =2.5:1; the optimum pH of complex and the nanoparticles preparation was 7.10 and 7.3, respectively; the optimital time of phase transferring and nanoparticle generation process was 30 min and 120 min.