The role of β,γ,δ-substituent of dialkylphosphinic acids in HREE extraction and separation behaviors

Heavy rare earth element(HREE) separation has always been a great challenge.The kind of dialkylphosphinic acids is recognized as the third generation of organophosphorous acid extractants.However,detailed relationship between β-substituent(especially when it changes from H to methyl,and further to ethyl) and their extraction behaviors and selectivity for HREEs have rarely been reported.Besides,there are also few reports on effect of γ,δ-substituent on HREE extraction and separation.In this paper...     

On the kinetics and mechanism of extraction of copper with β-hydroximes in the absence of mass transfer limitations

For a variety of experimental systems, the dependence of the rate of extraction of copper with pure, β-hydroximes on reagent concentration changes as a function of that concentration. Under experimental conditions where mass transfer limitations can be considered absent, the dependence can be explained using the Gibbs isotherm. The limiting conditions under which the dependence assumes certain specific forms are discussed. Finally, a mechanism is proposed which can explain the chemistry of the extraction for a wide range of reagent concentrations and experimental conditions.     

Catalytic conversion and DFT analysis of post DDBD-catalysis system for degradation of toluene,ethyl acetate and acetone with different metal-oxides catalysts

A series of multiphase metal-oxide catalysts(MnO_x/γ-Al₂O₃,CuO_x/γ-Al₂O₃,FeO_x/γ-Al₂O₃,CeO_x/γ-Al₂O₃and LaO_x/γ-Al₂O₃) were prepared for plasma-catalyst degradation of multicomponent volatile organic compounds(VOCs,such as toluene,acetone and ethyl acetate).The results reveal that the degradation efficiency(DE) of acetone,toluene and ethy...     

Adsorption of La3+ and Ce3+ by poly-γ-glutamic acid crosslinked with polyvinyl alcohol

With the exploitation of rare earth ore, more and more rare earth elements came into groundwater, caused waste of re-sources and toxicity to the organisms. This study aimed to find an efficient adsorpt...     

Determination of Sub-Trace Sc, Y and Ln in Carbonate by ICP-MS with Inter-Element Matrix-Matched Technique

Inductivelycoupledplasmamassspectrometry(ICP MS)isapowerfultechniquefortracemulti ele mentandisotopicanalysis[1,2 ] .Thistechniquecom binesthecharacteristicsoftheICPforatomizingandionizinginjectedmaterialwiththesensitivityofMS .Ithasbeensatisfactorilyappliedtotheanalysisofvari oussamplesinthefieldsofgeological,environmental ,industrial ,food ,medicalandnuclearsciences .How ever,highlevelsofmatrixelementcancausematrixeffectssuchasCa ,Mg ,K ,NaandCl .Severallitera tures[3～ 5] reportedthee…     

China''''s imports and exports of tungsten,molybdenum,tin and antimony by category

~~China's imports and exports of tungsten,molybdenum,tin and antimony by category~~     

Lanthanide complexes with β-diketones and coumarin derivates:synthesis,thermal behaviour,optical and pharmacological properties and immobilisation

The paper presents the results of the synthesis of complexes of the ty pe Eu(DBM) 3 and Eu(DBM) 3·Q(DBM-dibenzoylmethane,Q-1,10-phenantroline or 4,7-d iphenyl-1,10-phenantroline) and of Tb-and Nd-complexes with the newly-synthesis ed coumarin derivates 3,3’-[(4-chlorphenyl) methylene) bis(4-hydroxy-2H-chromen-2-one) ,3,3’-[(3,5-dimethoxy-4-hydroxy) methylene) bis(4-hydroxy-2H-chromen-2-one) ,etc. Elemental and thermogravimetric analysis,IR,UV,NMR and fluorescence spe ctroscopy and X-ray analysis were applied for characterisation of the complexes. Some peculiarities of the synthetic procedures for both types of complexes were discussed and the influence of the synthetic approach,pH of the reaction mediu m,temperature of synthesis and drying of the complexes on the composition,stab ility and optical properties was reported. The immobilisation of the complexes i n thin films based on sol-gel produced SiO2 and on polymethylmethacrylate was st udied. The optimal conditions for preparation of the matrices(composition of th e starting system,temperature and time of sol aging,etc.) were recommended. Th e film morphology was evaluated by fluorescence,scanning electron and atomic fo rce microscopy. The interaction of the lanthanide ions with the matrices and the influence of their nature,the effect of the in-situ polymerisation and other f actors on photoluminescent excitation and emission spectra and excited state lif e-times of the complexes were followed. The effect of the second ligand on the p hotoluminescence properties of the immobilised diketonates was further elucidate d. Processes involved in the thermal decomposition of the complexes and microcom posites produced on their base were proposed. Preliminary results on the pharmac ological properties of the coumarin complexes reported showed unambiguously high er cytotoxicity of the Nd complex in comparison with that of the respective ligand.     

Production of Ultrahigh-Strength and High-Ductility TWIP Steel by Precipitation of β-Mn during Large Deformation during Warm-Rolling

Herein, twinning-induced plasticity (TWIP) steel having large deformation is rolled at different rolling temperatures to improve the tensile strength and retain a certain plastic deformation capacity. Based on X-ray diffraction and transmission electron microscope analysis, β-Mn is found as the precipitate at the grain boundary during the warm-rolling process (500–650 °C). To investigate the impact of β-Mn on the tensile properties, the microstructure of the TWIP steel rolled at the temperature value of 600 °C is observed by carrying out electron backscatter diffraction and scanning electron microscope measurements. The intergranular β-Mn phase can help the material to accumulate geometric necessary dislocation (GND) density, inhibit crack propagation, as well as improve the strength and plasticity of the material. Once TWIP steel is warm-rolled above the temperature value of 600 °C, and serrated flow appears in the tensile process, which is also conducive to improving the material properties.     

Synthesis, X-ray structure and luminescent properties of Sm^3＋ ternary complex with novel heterocyclic β-diketone and 1,10-phenanthroline （Phen）

A new neutral ternary samarium complex Sm(Phen)HL3 in which Phen is 1,10-phenanthroline and HL is (1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)-1,3-propanedione) was synthesized. Molecular structure of this complex was determined by X-ray diffraction. Under UV-light this complex is demonstrated bright red luminescence (λmax=647 nm), which was corresponding to the electric dipole 4G5/2→6H9/2 transition in Sm3+ ion. UV-absorption, excitation and emission spectra of the title compound were investigated.     

Synthesis and fluorescence properties of Eu（Ⅲ）, Tb（Ⅲ） and Sm（Ⅲ） with β-diketone and 2,2＇- bipyridine

Three new rare earth ternary complexes,RE(PPP)3bpy(RE=Sm 3+ ,Eu 3+ ,Tb 3+ ),were synthesized by the reaction of 1-phenyl-3-(p-phenylethynylphenyl)-1,3-propanedione(HPPP)and 2,2′-bipyridine(bpy)with rare earth chloride RECl3,respectively,in alcohol solution. The compositions were characterized by means of infrared(IR)spectra,chemical analysis,elemental analysis,and thermodynamic analysis.Luminescent properties of the three complexes were studied.At room temperature,under UV light excitation,the Sm 3+ ,Eu 3+ and Tb 3+ complexes exhibited characteristic emission of the central ions.The fluorescence spectra showed that the fluorescence emission intensity of Eu 3+ complex was the strongest.The narrow strongest emission band of Eu 3+ complex was considered to be a valuable material with bright red fluorescence.     

Solvent extraction and separation of light rare earth elements (La,Pr and Nd) in the presence of lactic acid as a complexing agent by Cyanex 272 in kerosene and the effect of citric acid,acetic acid and Titriplex Ⅲ as auxiliary agents

At present, the use of rare earth elements(REEs) has become an inevitable necessity in many modern industries. In general, liquid extraction is the best commercial method for extracting REEs due to its ability to control high volumes of liquids with electrical load. With the aim of improving a separation technology that would be superior to the existing extraction systems, the extraction behaviors of La(Ⅲ),Pr(Ⅲ), and Nd(Ⅲ) from an HCI medium with Cyanex 272 in the presence of the complexing agent lactic acid(HLac) and auxiliary agents citric acid(H_3 Cit), acetic acid(HAc), and Titriplex Ⅲ have been reported.The effect of pH and lactic acid concentration has been examined. The use of lactic acid as a complexing agent leading to a high extraction of REEs with Cyanex 272 at pH = 5 was compared with systems without lactic acid. The results show that the use of acetic acid along with lactic acid leads to an increase in the extraction percentage of LREEs. While use of citric acid and Titriplex Ⅲ reduces the extraction percentage of LREEs. Finally, the presence of Titriplex Ⅲ together with lactic acid could lead to an increase in the separation factor of Pr and Nd.     

Solvent extraction and separation of light rare earth elements (La,Pr and Nd) in the presence of lactic acid as a complexing agent by Cyanex 272 in kerosene and the effect of citric acid,acetic acid and Titriplex III as auxiliary agents

At present, the use of rare earth elements (REEs) has become an inevitable necessity in many modern industries. In general, liquid extraction is the best commercial method for extracting REEs due to its ability to control high volumes of liquids with electrical load. With the aim of improving a separation technology that would be superior to the existing extraction systems, the extraction behaviors of La(III), Pr(III), and Nd(III) from an HCl medium with Cyanex 272 in the presence of the complexing agent lactic acid (HLac) and auxiliary agents citric acid (H₃Cit), acetic acid (HAc), and Titriplex III have been reported. The effect of pH and lactic acid concentration has been examined. The use of lactic acid as a complexing agent leading to a high extraction of REEs with Cyanex 272 at pH = 5 was compared with systems without lactic acid. The results show that the use of acetic acid along with lactic acid leads to an increase in the extraction percentage of LREEs. While use of citric acid and Titriplex III reduces the extraction percentage of LREEs. Finally, the presence of Titriplex III together with lactic acid could lead to an increase in the separation factor of Pr and Nd.     

Synthesis, X-ray structure and luminescent properties of Sm~(3+) ternary complex with novel heterocyclic β-diketone and 1,10-phenanthroline (Phen)

A new neutral ternary samarium complex Sm(Phen)HL3 in which Phen is 1,10-phenanthroline and HL is (1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)-1,3-propanedione) was synthesized. Molecular structure of this complex was determined by X-ray diffraction. Under UV-light this complex is demonstrated bright red luminescence (λmax=647 nm), which was corresponding to the electric dipole 4G5/2→6H9/2 transition in Sm3+ ion. UV-absorption, excitation and emission spectra of the title compound were investigated.     

Syntheses and fluorescent properties of complexes of Eu（III） with HTTA, TPPO and benzoic acid

A series of Eu(III) complexes of α-thenoyltrifluoroacetone(HTTA) with trioctylphosphine oxide(TPPO) and benzoic acid(BA) or its two derivatives, p-toluic acid(PTA) and p-methoxybenzoic acid(POA) were synthesized and were characterized with elemental analysis, IR spectroscopy, scanning electronic microscopy and fluorescent spectra. The complexes were revealed to be Eu(BA)(TTA)₂TPPO₂, Eu(PTA)(TTA)₂TPPO₂ and Eu(POA)(TTA)₂TPPO₂. The excitation and absorption spectra of the complex Eu(POA)(TTA)₂TPPO₂ in MeOH solution were investigated in detail. The experimental result showed that relatively cheap materials with sharp red luminescence could be prepared, when benzoic acid or its two derivatives were added in Eu(III) complexes of α-thenoyltrifluoroacetone with trioctylphosphine oxide. The relative fluorescence intensity of the Eu(III) complexes decreased in the following order: Eu(POA)(TTA)₂TPPO₂> Eu(PTA)(TTA)₂TPPO₂>Eu(BA)(TTA)₂TPPO₂.     

Synthesis,fluorescence properties of Tb(Ⅲ) complexes with novel mono-substituted β-diketone ligands

Two novel pyridine-2,6-dicarboxylic acid derivatives of mono-β-diketone named methyl 6-biphenylacetyl-2-pyridinecarboxylate (MBP) and 6-biphenylacetyl-2-pyridinecarboxylic acid (BAA) and their corresponding binary complexes Tb(MBP)3.6H2O and Tb(BAA)3·6H2O were synthesized. The ligands were characterized by elemental analysis, FT-IR and 1H-NMR, and the complexes were characterized with elemental analysis, FT-IR, 1H-NMR and thermogravimetric and differential thermal analysis(TG-DTA). The investigation of fluorescence properties of the complexes Tb(MBP)3·6H2O and Tb(BAA)3·6H2O showed that the introduction of the biphenyl enlarged the π-conjugated system of the ligands and enhanced the luminescent intensity of the complexes. The Tb(Ⅲ) ion could be sensitized more efficiently by the ligands, in particular, the fluorescence intensity of the complex Tb(BAA)3·6H2O was about 20% higher than that of Tb(MBP)3·6H2O and 30% higher than that of Tb(Ⅲ) complexes with bis-β-diketone-type ligands that we have previously reported.     

Deformation and fracture behavior of a directionally solidified β/γ′ Ni-30 At. pct Al alloy

The effect of a ductile γ′-Ni₃Al phase on the room-temperature ductility, temperature-dependent yield strength, and creep resistance of β-NiAl was investigated. Room-temperature tensile ductility of up to 9 pct was observed in directionally solidified β/γ′ Ni-30 at. pct Al alloys, whereas the ductility of directionally solidified (DS), single-phase [001] β-NiAl was negligible. The enhancement in ductility was attributed to a combination of slip transfer from the ductile γ′ to the brittle β phase and extrinsic toughening mechanisms such as crack blunting, deflection, and bridging. As in single-phase Ni₃Al, the temperature-dependent yield strength of these two-phase alloys increased with temperature with a peak at approximately 850 K. The creep strength of the β/γ′ alloys in the temperature range 1000 to 1200 K was found to be comparable to that of monolithic β-NiAl. A creep strengthening phase needs to be incorporated in the β/γ′ microstructure to enhance the elevated temperature mechanical properties.