Preparation and characterization of rare earth fluorescent anti-counterfeiting fiber via sol-gel method

A benzoic acid rare earth(Tb) complex was synthesized and characterized.The excitation and emission spectra of the complex were investigated,and then pure organic complex was incorporated with inorganic matrices(SiO2) through sol-gel method.The composition and structure of the hybrid complex was characterized through the IR spectra,TG,TEM and fluorescent spectrometer.Furthermore,the polypropylene(PP) fluorescent fiber with the organic-inorganic hybrid was prepared by melt spinning.The fluorescent and mechanical properties of the fiber were also tested.The results showed that after sol-gel coating the average particulate dimension of the hybrid rare earth complex was less than 100 nm and thermal stability was improved.Meanwhile,the fiber possessed excellent fluorescent and mechanical properties,which could be used as a candidate applied to excellent fluorescent anti-counterfeiting fiber.     

Preparation,luminescence and photofunctional performances of a hybrid layered gadolinium-europium hydroxide

The design and fabrication of rare earth ions incorporated into the inorganic/organic hybrid materials have attracted growing attention for seeking improved optical properties and photofunctional performances.In this paper,a novel hybrid composite based on the layered rare earth hydroxides was successfully prepared by the ion-exchange and intercalation chemical process.The rare earth elements in the composite contain gadolinium(Gd) and europium(Eu) and the molar ratio of Gd to Eu is kept constan...     

Thermal Stability and Luminescence Properties of Eu^3＋ and Tb^3＋ Complexes with a Silica Matrix by Sol-Gel Method

Ternary complexes of europium and terbium with benzoic acid and 1, 10-phenanthroline [RE(BA)3phen] (BA=benzoate phen=1,10-phenanthroline) were introduced into a silica matrix by sol-gel method. The thermal stability and luminescence behavior of the complexes in silica gels were studied in comparison with the corresponding solid-state complexes by thermal decomposition, excitation and emission spectra. The thermal stability of the complexes is enhanced in silica gel matrix and the luminescence remaines unchanged.     

Luminescent and Thermal Properties of Sm^ 3＋ Complex with Salicylate and o-Phenanthroline Incorporated in Silica Matrix

A ternary Sm（ Ⅲ ） complex with salicylate （sal-） and o-phenanthroline （phen） was synthesized and incorporated in silica matrix by sol-gel method. The luminescence behavior of the complex in silica gel was studied compared with that of the pure complex by means of emission, excitation spectra and thermogravimetic analysis. The results indicate that the fluorescence intensity ratio of the ^4G5/2→^6H9/2 transition to the ^4G5/2→^6H5/2 transition in silica gel doped with Sm（sal）3 （phen） is lower than that of the pure Sm（sal）3（phen）. The thermal stability of Sm（sal）3（phen） is enhanced greatly by the introduction of the complex into silica matrix. An isolated and chemical inert environment of the complex appears to be responsible for the thermal stability enhancement in silica gel.     

Study on Luminescence Properties of a Novel Rare Earth Complex Eu（ TTA）2 （N-HPA） Phen

A novel rare earth complex Eu（TTA）2（N-HPA）Phen （TTA = thenoyltrifluoroacetone, N-HPA = N-phenylanthranilic acid, and phen = 1,10-phenathroline ）, which contains three different ligands, was synthesized. The Eu complex was blended with poly N-vinylcarbazole （PVK） in different weight ratios and spin coated into films. The luminescence properties of films were investigated and energy transfer between PVK and the complex was discussed. Multilayer structural devices consisting of ITO/PVK： Eu （TTA）2 （N-HPA） phen/BCP/Alq3/Al were fabricated with PVK ： Eu （TTA）2（N-HPA） as light-emitting layer. Increasing the concentration of Eu in the PVK thin film would inhibit the emission of PVK to different degrees. Finally, the pure red luminescence of europium（ Ⅲ ） was observed when the doping weight ratio was approximately 1 ： 5, which indicated an effective energy transfer from PVK to rare earth complex.     

Incorporation of europium (Ⅱ) nanostructures into the channels of mesoporous silicon oxy-nitride for enhanced photoluminescence

Divalent europium(Ⅱ)-doped mesoporous silicon oxy-nitride materials, as a novel type of nanoscopic photoluminescent material, are studied in which the optically active luminescent centers are isolated within the pores, Colorless and transparent blue emitting luminous Eu~(2+)-doped mesoporous silicon oxy-nitride materials were prepared from mesoporous silica via impregnation, nanocasting and nitrogen-assisted carbothermal reduction and nitridation method. The morphology and porosity of the silica remain unchanged during the synthesis process as revealed by SEM images and by nitrogen sorption studies. Photoluminescence studies reveal a strong blue emission band for Eu~(2+) centered at 425 nm with a quantum efficiency of 47%. The luminescent intensity is greatly influenced by the amount of co-dopant, Al~(3+) ions.     

Synthesis and photoluminescence of a dendritic europium complex with carbazole moieties

A novel dendritic europium complex containing grafted carbazole units as functional peripheries was synthesized and characterized. The Foerster energy transfer from the peripheries of carbazole units to β-diketonate as well as from the hgands to the central Eu（Ⅲ） ions in the complex was demonstrated. Under the excitation of carbazole units and β-diketonate, characteristic red emission peaks at 612 nm with four shoulders due to the Eu（Ⅲ） ion transition of 5^D0→7^FJ （J=0-4） were observed for the complex.     

Preparation and properties of RE3+ doped luminescent co-polymer by solution copolymerization

Bonded type RE3+ doped luminescent co-polymer was synthesized by solution free radical copolymerization. The influence of charge sequence, monomers and co-polymerized method on properties and structures of the co-polymers was studied. The emission intensity of the co-polymers at different RE3+ concentrations was tested. The results showed that the co-polymers of Eu-PSt and Eu-PMMA both had wide absorption peak at 200-400 nm and the strongest peak appeared at 235 nm. The fluorescent intensity of Eu3+ doped polystyrene co-polymer was stronger than that of Eu3+ doped PMMA copolymer. The characteristic emission of europium ions was observed in the co-polymers. The copolymer doped with rare earth elements showed the "sensitization effect" for the central ions. The bonded-type rare earth copolymer not only enhanced the energy transfer efficiency, but also improved the fluorescence intensity by iacreasmg the rigidity of main and side chain.     

Formation Equilibria of Ternary Metal Complexes with Citric Acid and Glutamine （Alanine） in Aqueous Solution

The species and their formation constants in the ternary systems were obtained by the Scogs2 software from potentiometric titration data. The Comics software was used to calculate the distribution of species in the ternary systems.MLXH, MLXH2 and MLXH3 are the common species in these systems. The coordination behaviors of the rare earths are very similar and their stability is closely matched. The ternary rare earth complexes are more stable than the corresponding ternary complexes of calcium. The ternary zinc complex with glutamine as the secondary ligand is more stable than the corresponding complexes of rare earths, but the ternary complex with alanine as the secondary ligand shows an. inverse trend.The distributions of species in the ternary systems vary with pH changing. A prediction can be made that exogenous rare earths can affect the species of Ca and Zn in human body.     

Synthesis and optical properties of Eu~(3+) ion doped nanocrystalline hydroxya patites embedded in PMMA matrix

Transparent,luminescent and functional nanocomposites demonstrate interesting optical and mechanical properties suitable for many optoelectronic applications.Transparent polymethyl methacrylate(PMMA) polymer nanocomposites modified with thenoyl-trifluoroacetonate(TAA) were fabricated by in situ polymerization and used as hosts for homogenous dispersion of 3 mol.% Eu3+:Ca10(PO4) 6(OH) 2(Eu3+:HA) hydroxyapatite ～20 nm large nanocrystals.The emission,excitation and transmission spectra as well as the fluorescence decay rates of bare Eu3+:HA nanocrystallites,Eu3+:HA embedded in the PMMA and and Eu:HA embedded in the PMMA/TTA nanocomposites were studied.The improvement of transparency was demonstrated with the addition of TTA as well as europium doped hy-droxyapatites in comparison to pure PMMA matrix.The Judd-Ofelt analysis of f-f transitions of Eu3+:HA nanocrystallites,the PMMA/Eu3+:HA and the PMMA+TTA/Eu3+:HA was performed to investigate the optical behavior of the polymeric composites.     

Synthesis and Characterization of Rare Earth Luminescent Material Based on PEN

Novel polymer-PEN [poly(arylene ether) nitriles] was used as a sort of substrate hybrid material of rare earth complex and the solution of styrene was synthesized by solution copolymerization. The composition and structure of the rare earth luminescent polymer material were characterized by IR, SEM and XRD. The thermo property was characterized by STA. The results showed that by copolymerization, copolymer of styrene-α-methacrylic acid-rare earth based on PEN was prepared. The thermal analysis indicated that the heat-stability was improved. Moreover, the fluorescence spectra proved that the copolymer had good fluorescence property, and it showed characteristic fluorescence emission of rare earth europium.     

Study on Copolymer of PMMA with Eu Complex

The europium complex, Eu3 -1,10-phenanthroline (Phen) -acrylic acid (AA) was prepared and its structural formula is Eu(Phen) (AA)3. The high luminescence rare earth polymer materials were obtained by the copolymerization of europium complex with methyl methacrylate using AIBN as an initiator. The copolymer structure and properties were characterized by FT-IR, UV-Vis, RF spectra and thermogravimetric analysis (TG). Results indicate that block copolymer is synthesized. Fluorescent property shows that Eu copolymer emits rare earth fluorescence and the emission intensity increases with the rise in Eu content and reaches a maximum value.     

Preparation and characterization of rare earth fluorescent anti-counterfeiting fiber via sol-gel method

A benzoic acid rare earth (Tb) complex was synthesized and characterized. The excitation and emission spectra of the complex were investigated, and then pure organic complex was incorporated with inorganic matrices (SiO₂) through sol-gel method. The composition and structure of the hybrid complex was characterized through the IR spectra, TG, TEM and fluorescent spectrometer. Furthermore, the polypropylene (PP) fluorescent fiber with the organic-inorganic hybrid was prepared by melt spinning. The fluorescent and mechanical properties of the fiber were also tested. The results showed that after sol-gel coating the average particulate dimension of the hybrid rare earth complex was less than 100 nm and thermal stability was improved. Meanwhile, the fiber possessed excellent fluorescent and mechanical properties, which could be used as a candidate applied to excellent fluorescent anti-counterfeiting fiber.     

Predbaration and properties of polymeric colloidal crystals containing rare earth complexes

Rare earth organic complexes were introduced into the polymerization system, and the polymeric colloidal nanospheres containing rare earth complexes were prepared by emulsion copolymerization. The characterization results indicated that the polymeric spheres were small at nanometer size and the diameter was monodisperse, particularly the nanospheres possessed good fluorescent properties. Moreover, the polymeric nanospheres were self-assembled to fabricate the colloidal crystals, which were three-dimensional regular multilayer films. The polymeric colloidal crystal films exhibited excellent luminescent and novel optical properties.     

Preparation and properties of polymeric colloidal crystals containing rare earth complexes

Rare earth organic complexes were introduced into the polymerization system, and the polymeric colloidal nanospheres containing rare earth complexes were prepared by emulsion copolymerization. The characterization results indicated that the polymeric spheres were small at nanometer size and the diameter was monodisperse, particularly the nanospheres possessed good fluorescent properties. Moreover, the polymeric nanospheres were self-assembled to fabricate the colloidal crystals, which were three-dimensional regular multilayer films. The polymeric colloidal crystal films exhibited excellent luminescent and novel optical properties.     

邻氨基苯甲酸-联吡啶-混合稀土(Eu、Tb)配合物的荧光研究

:研究用邻氨基苯甲酸铵、2 ,2’-联吡啶与氯化铕、氯化铽在水 -乙醇溶液中反应合成了邻氨基苯甲酸- 2 ,2’-联吡啶 -铕铽异核稀土配合物 ,并测定了配合物的红外光谱。红外光谱数据表明 :邻氨基苯甲酸中的羧基和氨基均与稀土离子配位 ,联吡啶中的氮也与稀土离子配位 ;由元素分析数据推测 ,配合物的化学组成式为(Eux Tb1 - x) L3L′(其中 L 为邻氨基苯甲酸 ,L′为 2 ,2’-联吡啶 ) ;在 35 1nm紫外光激发下 ,研究了配合物的荧光光谱 ,结果表明 ,Eu3 的荧光发射被 Tb3 强烈敏化 ,而 Tb3 的荧光发射被 Eu3 离子强烈猝灭     

Synthesis, Characterization and Fluorescence Properties of Europium, Terbium Complexes with Biphenyl-4-Carboxylic Acid and o-Phenanthroline

Two series of solid complexes of europium and terbium with biphenyl 4-carboxylic acid and phen were synthesized and characterized in this report. Their elemental analysis, molar conductivities and TG-DTA studies indicate that the complexes have the composition of Eu(phen)L3·1/2H2O, Eu0.5RE0.5(phen)L3·1/2H2O; Tb(phen)L3·H2O and Tb0.5RE0.5(Phen)L3·1/2H2O. (RE=Y3 , La3 and Gd3 ; L=biphenyl 4-carboxylic acid; phen=o-Phenanthroline). The studies of their IR, UV 1H NMR and molar conductivities demonstrate that biphenyl 4-carboylic acid is bounded with RE(Ⅲ) ion. Rare earth ions coordinate with two nitrogen atoms of phen molecules directly in these rare earth complexes. The fluorescence spectra and fluorescence lifetimes of the rare earth complexes show that the fluorescent intensity and lifetime of a series of europium complexes are longer than those of the series of terbium complexes as having the some ligands. There are better fluorescent intensity and lifetime of hetero-nuclear rare earth complexes than homo-nuclear rare earth complexes for europium complexes. The fluorescence emission intensity of Eu3 is raised by inert fluorescent rare earth ions (Y3 , Gd3 and La3 ), but in Tb3 hetero-nuclear rare earth complexes the intensity of Tb3 ions are quenched by the inert fluorescent rare earth ions.     

稀土高分子发光材料的研究进展

稀土高分子材料是通过稀土金属与高分子的复合而制备的一类兼具稀土光、电、磁等特性和高分子质轻、抗冲击和易加工等优良综合性能的功能材料。通过配位或聚合的方法将稀土离子键合到高分子链上而获得高分子稀土金属配合物是20世纪80年代才出现的一类稀土有机材料,这类兼有稀土离子的光、电、磁特性和有机高分子优良的材料性能的功能材料,因可能作为荧光、激光和磁性材料等而引起人们极大的兴趣。