THE STUDY ON THE MASS TRANSFER MECHANISM OF EUROPIUM ION THROUGH LIQUID SURFACTANT MEMBRANES

The transfer of trivalent europium ion in a liquid surfactant membrane system is investigated in order toclarify the characteristics of liquid membrane separation process and the availability of this technique forrecovering trivalent lanthanides and actinides.A layered structure model for the emulsion globule is sug-gested.The equations describing the relationship among the effective membrane thickness,the time andother factors are derived and verified experimentally.Results show that under certain conditions the decreas-ing concentration of europium ion in the external phase is proportional to the square root of the time,the acidity of the internal phase and the carrier concentration in the membrane phase.The membrane phase consists of kerosene（solvent）,Span-80（surfactant）and di-（2-ethylhexyl） phosphoricacid（HDEHP,carrier）.The internal phase is dilute nitric acid and the external phase is aqueous solu-tion containing Eu（NO3）3.The mass transfer rate of europium in this system is high and the recovery ofeuropium may be more than 99%.

Structural and luminescence studies of europium ions in lithium aluminium borophosphate glasses

Eu3＋ doped borophosphate glasses with the chemical composition 20Li2O-30Al2O3-10B2O3-40P2O5-xEu2O3（where x=0.05 mol.%, 0.1 mol.%, 1.0 mol.%, 1.5 mol.% and 2.0 mol.%） were prepared by conventional melt quenching technique. The structural and luminescence properties of the prepared Eu3＋ doped borophosphate glasses were studied and compared with reported results. The XRD pattern showed the amorphous nature of the prepared glasses. Whereas, the FTIR spectra revealed the vibrational modes in the prepared glasses. The bonding parameters（ β and ？） were calculated through the excitation spectra. Judd-Ofelt（J-O） intensity parameters were calculated from the emission spectra and were used to determine transition probability（A）, stimulated emission cross-section（σE P）, radiative lifetime（τR） and branching ratios（βexp） for the transition 5D0→7Fj（j=1, 2, 3 and 4） of Eu3＋ ions. Furthermore, the luminescence intensity ratio（R） of 5D0→7F2 to 5D0→7F1 transition was also calculated. Transition 5D0→7F2 had the highest value of stimulated emission cross-section and branching ratios and the results were comparable with the reported values. This indicated that the present glass is promising host material for Eu3＋ doped fiber amplifiers.

Synthesis and Characteristic Study on Complexes of Europium(Ⅲ) and Maleic Acid Doped with Non-Fluorescent Ions

Complex of europium （Ⅲ） with maleic acid, and binuclear complexes of europium（Ⅲ）with maleic acid doped with non-fluorescent ions gadolinium, lanthanum and yttrium, were synthesized. The compositions and structures of complexes were characterized with elemental analysis, single crystal X-ray diffraction, IR and DSC-TG. Fluorescent properties were studied with fluorescence spectrum. The results indicated that the strongest fluorescent complexes were obtained when the ratio of europium and non-fluorescent ion was 8：2. The order of Eu^3＋ fluorescence strengthened by three doped rare earths was Gd^3＋ 〉La^3＋ 〉Y^3＋

铕修饰硅纳米颗粒可视化检测铜离子

为了实现对水中铜离子(Cu^(2+))的检测,设计开发了比率荧光探针铕修饰硅纳米颗粒(Eu-DPA@SiNPs)。在探针中,SiNPs作为参比信号,Eu^(3+)为响应信号,而2,6-吡啶二羧酸(DPA)作为“天线”敏化Eu^(3+)。采用透射电子显微镜(TEM)、傅里叶变换红外光谱(FTIR)、X射线衍射图谱(XRD)、紫外可见吸收光谱(UV-Vis)对探针进行形貌和结构的表征,用荧光光谱测试其检测性能。结果表明:当DPA与Eu^(3+)的摩尔比为0.5∶1时,探针具有最大淬灭效率;探针为均匀分散的球形颗粒,平均直径为26.15 nm;探针中加入Cu^(2+)后,10 s即反应完全,在0.2~13.0μmol/L范围呈现良好的线性关系,检出限(LOD)为0.41μmol/L,远低于美国环境保护署所规定的饮用水中Cu^(2+)含量最大允许限值,并成功将探针应用到实际水样中检测Cu^(2+);进一步制备了荧光检测试纸,实现了对Cu^(2+)的便携、可视化和半定量检测。

基于铕离子-四环素-草甘膦荧光增强体系结合分子印迹固相萃取测定环境样品中草甘膦的残留量

提出了基于铕离子-四环素-草甘膦荧光增强体系结合分子印迹固相萃取测定环境样品中草甘膦残留量的方法。以正硅酸乙酯为溶胶-凝胶功能单体,在pH 1.0的硅溶胶-凝胶体系中制备了草甘膦分子印迹固相萃取膜,用于环境水和土壤样品的前处理。将前处理后的样品溶液与1.5×10^(-2)mol·L^(-1)EuCl_(3)溶液、3.0×10^(-3)mol·L^(-1)四环素溶液和100 mmol·L^(-1)硼酸盐缓冲溶液(pH 10.0)按照一定比例混合,静置反应3 min;以403 nm为激发波长,根据体系在615 nm发射波长处的荧光强度增加值ΔF计算草甘膦的含量。结果表明:在较强碱性条件下,草甘膦的加入使体系在615 nm处的荧光强度显著增强;草甘膦浓度的对数在5.0×10^(-8)~1.5×10^(-4)mol·L^(-1)内与体系ΔF值呈线性关系,检出限(3s/k)为1.0×10^(-8)mol·L^(-1);草铵膦、氨甲基膦酸、常见金属离子以及结构类似的氨基酸等不干扰铕离子-四环素-草甘膦体系的荧光强度,而Fe^(3+)、Hg^(2+)会产生干扰,因此样品前处理过程中加入三乙醇胺进行掩蔽。方法用于实际环境水和土壤样品分析,草甘膦测定值与电化学法测定值基本一致;按照标准加入法对其中一个水样进行回收试验,草甘膦回收率为101%。

Preparation and Luminescent Characteristics of LaPO_4∶Eu Nanoparticles and Nanowires

Nanoparticles and nanowires of LaPO 4: Eu phosphors were synthesized by hydrothermal method. Their luminescent properties including electronic transition, surface effect, and temperature-dependent luminescent characteristics were systemically studied and compared to the bulk powders. It can be concluded that in comparison with the bulk powders, the fluorescence intensity decreases in nanoparticles and nanowires, while the lifetime increases, indicating that the radiative transition rate decreases. The nonradiative transition rate in nanowires decreases than that in nanoparticles due to its decreased surface to volume ratio. The temperature-dependent experiments indicate that the thermal quenching in nanopowders becomes weaker than that in the bulk powders.

Emission Spectra and Crystallographic Sites of Eu^(2+) in Ca_8Zn(SiO_4)_4Cl_2

The fluorescent characteristic and emission spectra of Eu^(2+) in the cubic structure Ca_8Zn(SiO_4)_4Cl_2 with three kinds of cation sites is reported.The influence of temperature,Eu^(2+) concentra- tion and excitation conditions on fluorescent properties of Eu^(2+) are studied at 77 and 298 K.The coordination number of Eu^(2+) at different sites is obtained.The green and red emission bands arise from Eu_(2+) ions locating on eight- and six- coordinated inequivalent sites respectively.

基于Eu^(3+)-生物质碳量子点探针的比率型荧光传感体系检测盐酸四环素

该文以橙皮为原料制备的碳量子点(CDs)与铕离子(Eu^(3+))构建双发射比率型荧光探针(Eu^(3+)-CDs)并用于抗生素盐酸四环素的检测。在370 nm激发波长下,Eu^(3+)-CDs荧光探针在425 nm处出现较强的蓝色荧光峰,在617 nm处出现较弱的红色荧光峰。随着盐酸四环素浓度的逐渐增大,Eu3+与盐酸四环素螯合形成的配合物增多,在425 nm处的CDs荧光(I_(F425))逐渐减弱,而617 nm处铕配合物的荧光(I_(F617))逐渐增强,可基于荧光强度比I_(F617)/I_(F425)的变化对盐酸四环素进行测定。考察了Eu^(3+)的浓度、pH值和反应时间对探针荧光强度的影响。在最佳条件下,该双发射比率型荧光探针对盐酸四环素具有特异性识别能力,荧光强度比(I_(F617)/I_(F425))与盐酸四环素浓度在10~100µmol/L范围内存在良好的线性关系,相关系数r^(2)=0.9926,检出限为5.09µmol/L。该方法成功用于猪肉中盐酸四环素含量的检测,加标回收率为102%~110%,相对标准偏差为0.20%~2.4%,具有较好的实用性。

Preparation, Photo and Electroluminescence Properties of Novel Rare Earth Aromatic Carboxylates

Novel soluble rare earth aromatic carboxylates were prepared. The triplet energy level of organic ligand was measured. The photoluminescence properties of the Tb 3+ and Eu 3+ aromatic carboxylates and lifetimes were investigated, which indicated that these rare earth complexes have high quantum efficiency. Because of their excellent solubility, polymer-doping rare earth carboxylates were fabricated as thin films by spin-coating method and their luminescence properties were studied. Some rare earth organic light-emitting diodes were successfully fabricated which performed high pure color. The maximum luminance of the device of ITO/PVK/PVK∶Tb(AS) 3Phen∶PBD/PBD/Al is 32 cd·m -2 at 28 V.

铕掺杂改善锂离子电池正极材料LiFePO_(4)电化学性能研究

橄榄石结构的LiFePO_(4)正极材料因其多重优势被广泛应用于新能源汽车和储能领域,但其较差的电导率和缓慢的锂离子扩散速率限制了其低温和倍率等性能。元素掺杂被认为是一种改善正极材料倍率、低温等性能的有效策略。采用固相法合成了稀土金属铕掺杂的Li Fe_(1-x)Eu_(x)PO_(4)/C正极材料,并研究了铕掺杂量对Li Fe PO_(4)形貌、结构和电化学性能的影响。结果表明,铕掺杂能够改善Li Fe PO_(4)/C的电化学性能,其中Li Fe_(0.97)Eu_(0.03)PO_(4)/C表现出最佳的倍率、低温和循环性能,其组成的纽扣电池在20C高倍率下放电比容量为95.1 m A·h/g(较Li Fe PO_(4)/C提升57.7%),在低温(-20℃、0.1C)下的放电比容量为81.5 m A·h/g(较Li Fe PO_(4)/C提升73.8%),1C下经200次循环后其容量保持率为96.43%(较Li Fe PO_(4)/C高出2.46%)。X射线衍射分析和扫描电镜分析结果表明,铕的掺入能增大Li Fe PO_(4)的晶胞体积,降低Li和O原子之间的结合能,从而提高锂离子的扩散速率。电化学交流阻抗测试结果表明,Li Fe_(0.97)Eu_(0.03)PO_(4)/C表现出最低的电荷转移电阻和最高的锂离子扩散系数,其锂离子扩散系数比未掺杂的Li Fe PO_(4)/C高出2个数量级,这解释了其出色的倍率、低温和循环性能。

Fabrication and Magnetic Properties of Highly Oriented ZnO:Eu Films by Sol-Gel Process

A series of Eu-doped ZnO films were prepared by a sol-gel method. Precursor and films were characterized by thermal analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), UV-vis spectra, as well as the magnetism measurement. The wurtzite structure of obtained films presents an extreme high c-orientation character. The film susceptibility resembles a Curie-Weiss behavior at high temperature, and presents an obvious enhancement at low temperature, indicating the presence of antiferromagnetic interactions in the Zn0.9Eu0.1O films.

Electron Transition of Eu^(2+) and Energy Transfer in Crystals BaFX:Eu^(2+),Eu^(3+) (X=Cl,Br)

In crystals BaFX:Eu^(2+)(X=Cl,Br).there exists configuration interaction between 4f^65d and 4f^65s ex- cited state of Eu^(2+)ion.and it results in the change of relative intensities of d-f and f-f transition.The transition ~S_-_2→4f^65d-6s is observed.The variation of F/X atomic ratio between 110/90 and 90/110 does not obvi- ously influence the luminescence of BaFX:Eu^(2-).There is energy transfer between Eu^(2+)(f-f)and Eu^(3+)which coexists in the matrices.

Preparation and Fluorescent Property of Eu-Doped High Silica Glasses

A method to fabricate europium ions doped-high silica glass for transparent fluorescence materials based on the fabrication and sintering technique of nano-porous silica glass was reported. Glasses impregnated with Eu ions and sintered at above 1150℃in a reduction atmosphere show a very strong blue light from an emission band at about 430 nm due to the 4f65d→4f7(8S7/2) transition of the Eu2+ ions. On the other hand, the Eu-doped glass obtained by co-impregnated with Y3+ and V5+ ions and sintering in oxidation atmosphere behaves a very strong red emission band at about 615 nm with a UV excitation. An appearance of vanadate band in the excitation spectrum of Eu3+ , Y3+ .and V5+ ions co-doped high silica glass implies an effective energy transferring from VO43- to Eu3+ and effective excitation of Eu3+ by about 500 nm strong broad emission of VO43- .

Bright Red Luminescence and Structural Properties of Eu³⁺Ion Doped ZnO by Solution Combustion Technique

Pure, and Europium ion doped Zinc oxide nanocrystals (ZnO:Eu3+) were synthesized by a solution combustion technique. The X-ray diffraction patterns (XRD) reveals the existence of the Eu2O3 phase. From the results of both, X-ray diffraction and photoluminescence spectra (PL) reveal that Eu3+ ions successfully substitute for Zn2+ ions in the ZnO lattice, moreover, when the amount of doped Europium was varied, this changes are showed in changes in the luminescence intensity. The PL is broad and a set of colors was emitted which originates from ZnO and the intra 4f transitions of Eu3+ ions. The existence of the Zn-O, Eu3+-O and O1s bonding energies were confirmed by X-ray photoelectron spectroscopy (XPS) technique. The samples morphology was registered by a scanning electron microscopy (SEM) technique, and reveals that Europium ions are present on the surface of the ZnO nanocrystals.

Characterization of Fluoride Phosphors for Diode Pumped Solid-State Lighting Applications

Phosphor coated diodes are critical to the lighting industry. Rare-earth doped fluoride phosphors are characterized in this work. Spectroscopy and lifetime measurements of CaF2: Dy3+, LaF3: Eu3+ and Tb3+-doped LaF3 and CaF2 crystals were performed by irradiating the samples with 405 and 375 nm diode lasers. Chromaticity diagrams are developed from spectral measurements. Dy3+-doped CaF2 revealed bright white light emission having peaks at 492, 570 and 654 nm. The measured color coordinates are x = 0.322 and y = 0.340 for Dy3+-doped CaF2 and these values are close to those of sunlight and the coordinated color temperature is 6147 K, under 405 m laser excitation. Eu3+-doped LaF3 revealed twenty emission peaks in the visible wavelength region. The color coordinates measured for LaF3: Eu3+ are x = 0.283 and y = 0.293 under 405 nm diode laser excitation and the color temperature is 9557 K. Eu3+-doped LaF3 provides cool white-light, under 405 nm diode laser excitation. Tb3+-doped fluoride crystals revealed bright white light under low power diode laser excitation. The measured color coordinates for Tb3+-doped CaF2 are x = 0.329 and y = 0.558 and the color temperature is 7713 K. The color coordinates for LaF3: Tb3+ are x = 0.342 and y = 0.365 and the coordinated color temperature is 5370 K. These values are close to those of sunlight.

基于智能手机及机器学习技术对食品中多种抗生素的识别

基于铬黑T与铕离子构建了比色和荧光双通道探针(EBT/Eu^(3+)),利用智能手机颜色识别和荧光测试获得四种四环素加入EBT/Eu^(3+)后颜色和荧光信号的变化,结合机器学习中模式识别方法,成功实现了蜂蜜中四种四环素的识别。本实验将探针制备、智能手机颜色获取、荧光测试、机器学习、多种抗生素识别等多个知识点进行创新融合,综合性强。

聚甲基丙烯酸甲酯稀土铕配合物的合成制备及其表征

本文研究目的是制备一种含有稀土铕的有机高分子材料.首先以三价稀土铕离子为中心原子,与苯甲酸和丁烯酸反应制备了Eu^(3+)-苯甲酸-丁烯酸配合物(Eu-BA-CA);再使其与邻菲罗啉结合生成Eu^(3+)-苯甲酸-丁烯酸-邻菲罗啉配合物(Eu-BA-CA-phen);然后该配合物与甲基丙烯酸甲酯单体聚合,得到高分子铕配合物(Eu-BA-CA-phen-PMMA).通过对其进行溶解性研究,并利用红外光谱、核磁共振氢谱、凝胶渗透色谱、紫外光谱、差示扫描量热分析和荧光光谱等对铕配合物组成、结构进行表征.结果显示:成功制备了聚甲基丙烯酸甲酯高分子铕配合物,该高分子铕配合物在丙酮中具有良好的溶解性,并研究了该共聚物的发光性质.

铕掺杂对纳米TiO_2的光催化活性的影响

用溶胶 -凝胶法制备了掺杂 Eu3+ 的纳米 Ti O2 ,用 XRD和 TG-DTA对其进行了表征 ,并以正庚烷为气相有机污染物的实例研究了样品的光催化活性 ,发现 Eu3+ 进入 Ti O2 晶格中引起了 Ti O2 晶格膨胀 ,导致晶格畸变增大 ,抑制了 Ti O2 晶相的转变和粒径的增长 .结果表明 ,Eu3+ 掺杂可提高 Ti O2 的光催化活性 ,并且当掺杂摩尔分数为 0 .3 %时 ,光催化活性最好 .随着焙烧温度的升高 ,光催化活性下降 ,而利用较高的水解酸度则有利于得到光催化活性较高的样品 .

新型稀土芳香羧酸类配合物的合成及其光致和电致发光性质

合成了新型可溶性稀土芳香羧酸类配合物,测定了有机配体的三重态能级,并考察了其光致发光相对强度、荧光寿命,发现该系列稀土配合物具有很高的光致发光效率。利用其优良的溶解性,采用高聚物掺杂、旋涂技术将其制成薄膜应用于电致发光研究中,成功地制备出具有高色纯度的稀土有机电致发光器件。对于ITO/PVK/PVK∶Tb(AS)3Phen∶PBD/PBD/Al电致发光器件,其最大亮度为32cd·m-2。

Eu^(3+)在La_2O_2S中的长余辉发光

The new Eu 3+ doped lanthanum oxysulfide phosphors,which have the orange-red long afterg low emission,were synthesized by solid-state reaction method.The synthesized phosphors were characterized by X-ray diffraction.The excitation and emission spectra,afterglow spectra and afterglow decay curves were examined.XRD confirm ed the phosphor as pure phase La 2 O 2 S.The phosphors showed typical transitions 5 D J (J=0,1) → 7 F J (J=0,1,2,3,4)of Eu 3+ .The photoluminescence spectra and afterglow spectra presented the regular alteration with various Eu 3+ concentration,due to cross relaxation between energy levels of Eu 3+ .In addition,we studied the effects of activator concentration and dopants species on the afterglow property.The data showed afterglow result was the bes t with2%Eu 3+ and doped with Mg 2+ and Zr 4+ .A prominent phosphorescence can be seen in this phosphor after illuminated with UV light.