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

ＳｉｎｃｅＫｉｄｏｅｔａｌ.ｈａｖｅｆｉｒｓｔｒｅｐｏｒｔｅｄｏｎｏｒｇａｎｉｃｅｌｅｃｔｒｏｌｕｍｉｎｅｓｃｅｎｃｅ (ＥＬ)ｕｓｉｎｇｒａｒｅｅａｒｔｈ (ＲＥ)ｃｏｍｐｌｅｘａｓｔｈｅｅｍｉｔｔｉｎｇｌａｙｅｒ[1] ,ｍｕｃｈｗｏｒｋｈａｓｂｅｅｎｆｏｃｕｓｅｄｏｎｔｈｉｓｆｉｅｌｄｄｕｅｔｏｉｔｓｈｉｇｈｃｏｌｏｒｐｕｒｉｔｙ[2～ 4] .Ｈｏｗｅｖｅｒ,ｔｈｅｋｅｙｐｒｏｂｌｅｍｗｉｔｈｒａｒｅｅａｒｔｈβ ｄｉｋｅｔｏｎｅｃｏｍｐｌｅｘｅｓｉｓｔｈｅｉｒｐｏｏｒｔｈｅｒｍａｌｓｔａｂｉｌｉｔｙａｎｄ…     

表面处理对BaFCI:Eu~(2+)发光性质的改进

利用正硅酸乙酯的水解,在BaFCl:Eu~(2+)荧光粉表面上形成一定厚度(40～60nm)的SiO_2表面层,它能有效地促进基体对激发能量的吸收,改变发光中心的化学环境,对荧光粉的发光性质产生较大影响。发光强度因此提高14％～19％。     

Preparation of Sr1−xCaxLiAl3N4:Eu2+ Solid Solutions and Their Photoluminescence Properties

A series of quaternary nitride solid solutions with a general formula of Sr_1?xCa_xLiAl₃N₄:0.5%Eu²⁺ was synthesized by a solid‐state reaction method. The experimental results showed that a proper amount of Ca‐doping can improve the crystallinity and the photoluminescence properties of the produced phosphors. Rietveld refinement showed that the volume of the unit cell shrank with the increase of Ca substitution for Sr, which resulted in a red shift of the emission spectra from 654 to 665 nm under blue excitation at 475 nm. Rietveld refinement and CASTPE calculations suggested that Ca²⁺ ions prefer to occupy the smaller Sr(I) sites in the crystal lattice, which increases the amount of Eu²⁺ ions in Sr(II) sites and enables the tuning of the chromaticity coordinates of the obtained phosphors. The thermal stability of the produced phosphors is better than that of commercial Sr₂Si₅N₈:Eu²⁺ phosphor. The experimental results qualify the solid‐solution Sr_1?xCa_xLiAl₃N₄:0.5%Eu²⁺ for consideration as a potential candidate for application in white LEDs.     

Sorption of Eu3+ on Na-montmorillonite studied by time-resolved laser fluorescence spectroscopy and surface complexation modeling

The influence of pH and concentrations of Eu³⁺ and NaNO₃ on the sorption of Eu³⁺ to Na-montmorillonite were investigated through batch sorption measurements and time-resolved laser fluorescence spectroscopy. The pH had little effect on the distribution coefficients (K_d) in the range of pH 4–7 at 0.01 M NaNO₃, which indicates that the cation exchange reaction is a dominant sorption process. Meanwhile, the K_d strongly depended on pH at 1 M NaNO₃, suggesting the formation of inner-sphere surface complexes. A cation exchange model combined with a one-site non-electrostatic surface complexation model was successfully applied to the measured K_d data. Linear free-energy relationship was used to estimate the formation constants of the surface species from those of the corresponding aqueous hydrolyzed species. The TRLFS spectra of Eu³⁺ sorbed on Na-montmorillonite were processed by parallel factor analysis, which provided the fluorescence spectra, decay lifetimes, and relative intensity profiles of three Eu³⁺ surface species. These species corresponded to one outer-sphere (factor A) and two inner-sphere (factors B and C) complexes. It turned out that factors A and B correspond to Eu³⁺ sorbed by ion exchange to permanent charge sites of Na-montmorillonite and inner-sphere complexation with surface hydroxyl groups of the edge faces. Factor C became dominant at relatively high pH and ionic strength and likely corresponded to the precipitation of Eu(OH)₃ on the surface of Na-montmorillonite.     

掺铕钴基复合催化剂的制备与性能

为了提高钴基催化剂的催化性能,采用稀土元素铕对钴基催化剂进行改性,通过TG-DSC、SEM、BET检测和甲烷催化燃烧试验等方法研究了加入聚乙烯醇并进行了超声处理对水热法制备掺铕钴基复合催化剂结构与性能的影响。结果表明:加入聚乙烯醇并进行超声处理制备出的掺铕钴基复合催化剂表面具有明显的孔道;在500~600℃其催化性能比改性前的钴基催化剂提高了22%~47%。     

PMA—Eu^3＋—TPPO等三元配合物的合成与发光性质研究

合成了PMA-Eu与TPPO（Phen、Bipy)形成的系列固体配合物,分析了它们的组成,常温下研究了它们的荧光光谱。发现TPPO（Phen、Bipy)作第二配体加入到Eu^3 的配合物中,能使Eu^3 的红色荧光大大增强,其中TPPO比Phen、Bipy对Eu^3 具有更好的荧光增强效果。     

Gd2O3:Eu荧光粉体的制备及其发光特性

分别采用溶胶-凝胶/燃烧合成结合法和共沉淀法合成了Gd2O3:Eu粉体,借助X射线衍射、扫描电镜、透射电镜、分光光度计等分析手段,对比研究了两种工艺制备Gd2O3:Eu荧光粉体的物相组成、形貌及荧光特性.结果表明:共沉淀法合成的Gd2O3:Eu为立方相;溶胶-凝胶/燃烧合成法制备的Gd2O3:Eu为单斜相.溶胶-凝胶/燃烧合成法制备的Gd2O2:Eu粉体蓬松、多孔,但存在一定程度的团聚.共沉淀法制备的立方相Gd2O3:Eu粉体在610 nm处呈现Eu2 的特征荧光;溶胶-凝胶/燃烧合成法制备的单斜相Gd2O3:Eu的发射波长产生红移,其中最强的2个发射峰起源于Eu3 的5D0→7F2跃迁,分别位于612 nm和621 nm.两种工艺制备Gd2O3:Eu粉体荧光特性的差异是由Eu3 在这两种粉体中所处晶格结构的对称性差异引起的.     

Synthesis and Characterization of 6,6ˊ-bis(1-(2-ethylhexyl)-1H-1,2,3-triazol-4-yl)-2,2ˊ-bipyridine (EH–BTzBP) for Actinide/Lanthanide Extraction and Separation

A new N-donor extractant, 6,6ˊ-bis(1-(2-ethylhexyl)-1H-1,2,3-triazol-4-yl)-2,2ˊ-bipyridine (EH-BTzBP), was synthesized and tested for Am(III)/Ln(III) extraction and separation. EH-BTzBP in combination with 2-bromohexanoic acid (as lipophilic anion source) selectively extracts Am(III) from acidic solutions (HNO₃ ≤ 0.1M) with Am(III)/Eu(III) separation factors of about 70. Phase transfer kinetics is rapid, back-extraction of metal ions posed no issues, and there is no evidence of ligand degradation by acid hydrolysis or contact with hydrogen peroxide (which simulates some effects of radiolysis).     

含氮杂菲类中性配体的铕配合物电致发光研究

文章用一系列含氮杂菲类中性配体的铕配合物Eu（DBM）3pyzphen、Eu（DBM）3dpmq、Eu（DBM）3dppz和Eu（DBM）3dptp制作了有机EL器件,研究了它们的电学特性。采用的器件结构为ITO/TPD/CBP：Eu（DBM）3L/BCP/Alq3/LiF/Al（L=pyzphen、dpmq、dppz和dptp）,其中基于Eu（DBM）3pyzphen的器件获得了992cd/m2的最大亮度和2.9cd/A的最大效率。在此基础上分析了第二配体对器件性能的影响。     

On-Demand Removable Self-Healing and pH-Responsive Europium-Releasing Adhesive Dressing Enables Inflammatory Microenvironment Modulation and Angiogenesis for Diabetic Wound Healing

Current diabetic wound treatments remain unsatisfactory due to the lack of a comprehensive strategy that can integrate strong applicability (tissue adhesiveness, shape adaptability, fast self-healability, and facile dressing change) with the initiation and smooth connection of the cascade wound healing processes. Herein, benefiting from the multifaceted bonding ability of tannic acid to metal ions and various polymers, a family of tannin–europium coordination complex crosslinked citrate-based mussel-inspired bioadhesives (TE-CMBAs) are specially developed for diabetic wound healing. TE-CMBAs can gel instantly (< 60 s), possess favorable shape-adaptability, considerable mechanical strengths, high elasticity, considerable wet tissue adhesiveness (≈40 kPa), favorable photothermal antimicrobial activity, excellent anti-oxidant activity, biocompatibility, and angiogenetic property. The reversible hydrogen bond crosslinking and sensitive metal–phenolic coordination also confers TE-CMBAs with self-healability, pH-responsive europium ion and TA releasing properties and on-demand removability upon mixing with borax solution, enabling convenient painless dressing change and the smooth connection of inflammatory microenvironment modulation, angiogenesis promotion, and effective extracellular matrix production leveraging the acidic pH condition of diabetic wounds. This adhesive dressing provides a comprehensive regenerative strategy for diabetic wound management and can be extended to other complicated tissue healing scenarios.