- Synthesis and characterization of magnetic mesoporous Fe3O4@mSiO2-DODGA nanoparticles for adsorption of 16 rare earth elements
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In this study, novel magnetic mesoporous Fe3O4@mSiO2-DODGA nanoparticles were prepared for efficiently adsorbing and recycling REEs. Fe3O4@mSiO2-DODGA was characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The adsorption behavior of Fe3O4@mSiO2-DODGA was investigated by ICP-OES. The results showed that the content of DODGA in the adsorbent was 367 μmol g-1. Fe3O4@mSiO2-DODGA exhibited the highest adsorption rates for 15 REEs, except Tm, in a 2 mol L-1 nitric acid solution. Among these elements, the adsorption rates for Nd, Sm, Eu, Dy, Ho, Yb, Lu, Y and Sc ranged from 85.1% to 100.1%. The desorption rates for all 16 REE ions reached their maximum values when 0.01 mol L-1 EDTA was used as the eluent. The desorption rates for Nd, Ce, Sm, Eu, Ho, Yb, Lu, Y, and Sc were 87.7-99.8%. Fe3O4@mSiO2-DODGA had high stability in 2 mol L-1 HNO3 and could be used five times without significant loss of adsorption capacity. Moreover, these nanoparticles had high selectivity, and their adsorption rate was not affected even in a high-concentration solution of a coexisting ion. Therefore, 8 REE ions (Nd, Sm, Eu, Ho, Yb, Lu, Y, and Sc) were selected for the study of adsorption kinetics and adsorption isotherm experiments. It was demonstrated that the values of Qe (equilibrium adsorption capacity) for Nd, Sm, Eu, Ho, Yb, Lu, Y, and Sc were 14.28-60.80 mg g-1. The adsorption of REEs on Fe3O4@mSiO2-DODGA followed the pseudo-second-order kinetic model, Elovich model and Langmuir isotherm model, which indicated that the adsorption process of Fe3O4@mSiO2-DODGA for REEs comprised single-layer adsorption on a non-uniform surface controlled by chemical adsorption. It was concluded that Fe3O4@mSiO2-DODGA represents a new material for the adsorption of REEs in strongly acidic solutions.
- Li, Jingrui,Gong, Aijun,Li, Fukai,Qiu, Lina,Zhang, Weiwei,Gao, Ge,Liu, Yu,Li, Jiandi
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- A comparative study on the coordination of diglycolamide isomers with Nd(iii): extraction, third phase formation, structure, and computational studies
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A novel asymmetric diglycolamideN,N-dimethyl-N′,N′-dioctyl diglycolamide (LII) was synthesized. The Nd(iii) extraction behavior from HNO3and loading capability of the solution of LIIin 40/60 (v/v)%n-octanol/kerosene were studied. Analyses by the slope method, ESI-MS, and FT-IR indicated that, similar to the previously studied isomer ligandN,N′-dimethyl-N,N′-dioctyl diglycolamide (LI), 1?:?3 Nd(iii)/LIIcomplexes formed. Under the same experimental conditions, the distribution ratio and limiting organic concentration of LIItowards Nd(iii) were smaller than those of LI, but the critical aqueous concentration of LIIwas larger, which implies that LIIexhibited poorer extraction and loading capabilities towards Nd(iii) than LI, and LIIhas a tendency to be less likely to form the third phase. The quasi-relativistic density functional theory (DFT) calculation was performed to provide some explanations for the differences in their extraction behaviors. The electrostatic potential of the ligands indicated that the electron-donating ability of the amide O atoms in LIIdisplayed certain differences compared with LI. This inhomogeneity in LIIaffected the interaction between LIIand Nd(iii), as supported by QTAIM and bonding nature analysis, and it seemed to reflect in the extraction performance towards Nd(iii).
- Gao, Yang,He, Hui,Jiao, Caishan,Li, Chunhui,Liu, Sheng,Liu, Yaoyang,Liu, Zhibin,Zhang, Shaowen,Zhao, Chuang,Zhou, Yu
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p. 27969 - 27977
(2021/09/15)
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- Diglycolamide Based Mono and Di-Ionic Liquids Having Imidazolium Cation for Effective Extraction and Separation of Pb(II) and Co(II)
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Abstract: Two glycolamide based functionalized ionic liquids (ILs) having imidazolium cations namely LI (mono-ionic) and LII (di-ionic) were synthesized for the extraction of Pb(II) and Co(II) from waste water. The synthesized ligands were characterized by FTIR and NMR spectroscopy. The extraction efficiency of both mono- and di-ionic liquids was evaluated in terms of contact time, pH of the aqueous phase and metal ion concentration. The metal extraction was carried out at various pH values viz. 2, 4, 6, 8, and 10 whereas, at contact time of 15, 30, 45, 60, and 75 minutes. The optimized pH of 4 and equilibration time of 75 minutes was further utilized for extraction at various metal ions concentration (50, 100, 150, 200, and 250 ppm). LI exhibited low equilibration time as compared to LII whereas, both ligands showed maximum extraction at a pH of 4. A very high extraction efficiency of up to 99% for both metals was observed with LI and LII under optimized conditions. In addition to that effective separation of Co(II) and Pb(II) was observed at pH 10.
- Azra, N.,Iqbal, M.,Mehmood, T.,Waheed, K.
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p. 1040 - 1046
(2021/07/17)
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- Study on the extraction of lanthanides by isomeric diglycolamide extractants: An experimental and theoretical study
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Two isomeric diglycolamide (DGA) extractants, N,N′-dimethyl-N,N′-dioctyl diglycolamide (LI) and N,N-dimethyl-N′,N′-dioctyl diglycolamide (LII), were used to perform a comparative study on the extraction performances towards several lanthanides by extraction experiments and theoretical calculations. The experimental results show that both LI and LII show a positive sequence on the extraction of lanthanides, and LI exhibits the higher complex ability with these lanthanides than LII, except for La and Ce. Slope analysis shows that 1:2 or 1:3 complexes are formed between the two ligands and the metal ions. The geometrical structures of the complexes were optimized in the gas phase by density functional theory (DFT) on the basis of complex compositions. The results of bond lengths, MBOs and topological analysis indicated that the electrostatic interaction between metal ions and two amide O atoms in the LII ligand is not as homogeneous as in LI, and this inhomogeneity is likely to be related to the poor extraction performance of LII.
- Gao, Yang,He, Hui,Jiao, Caishan,Liu, Sheng,Liu, Yaoyang,Liu, Zhibin,Zhang, Meng,Zhang, Shaowen,Zhao, Chuang,Zhou, Yu
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p. 790 - 797
(2022/01/22)
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- Novel process for synthesizing N,N,N',N'-tetraoctyl-3-oxyglutaramide
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The invention provides a novel process for synthesizing N,N,N',N'-tetraoctyl-3-oxyglutaramide (TODGA). The novel process includes the steps of firstly, allowing diglycolic acid to have reaction with SOCl2 to generate diglycolic acyl chloride, and allowing the diglycolic acyl chloride to have reaction with amine to generate part of TODGA; secondly, removing components, which can be easily dissolvedin water, in the byproducts, and separating to obtain monooxaamide carboxylic acid; thirdly, allowing the monooxaamide carboxylic acid to have reaction with amine to generate part of TODGA again. Bythe novel process with the features of an existing process, high yield is achieved.
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Paragraph 0026; 0028-0030; 0032-0034; 0036; 0037
(2019/07/04)
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- NITRILOACETATE DIACETAMIDE COMPOUND, EXTRACTANT, AND EXTRACTION METHOD
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PROBLEM TO BE SOLVED: To provide useful new compounds, particularly a compound that can be used as an extractant for extracting a valuable metal, such as a rare metal and a noble metal, or a toxic metal having high toxicity. SOLUTION: A compound represented by the general formula (1) or a salt thereof can be used as an extractant for extracting a valuable metal, such as a rare metal and a noble metal, or a toxic metal having high toxicity. (In the formula (1), R1, R2, R3 and R4 represent hydrocarbon groups identical to or different from each other, provided that the total number of carbon atoms in the R1, R2, R3 and R4 hydrocarbon groups is from 8 to 64.) SELECTED DRAWING: Figure 2 COPYRIGHT: (C)2017,JPOandINPIT
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Paragraph 0031
(2017/07/19)
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- AMIDATED PHOSPHORIC ACID ESTER COMPOUND, EXTRACTANT, AND EXTRACTION METHOD
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PROBLEM TO BE SOLVED: To provide useful new compounds, particularly a compound that can be used as an extractant for extracting a valuable metal, such as a rare metal and a noble metal, or a toxic metal having high toxicity.SOLUTION: A compound represented by the general formula (1) or a salt thereof can be used as an extractant for extracting a metal element. (In the formula (1), R1, R2 and R3 represent hydrocarbon groups identical to or different from each other, provided that the total number of carbon atoms in the R1, R2 and R3 hydrocarbon groups is from 8 to 48.)SELECTED DRAWING: Figure 2COPYRIGHT: (C)2017,JPOandINPIT
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Paragraph 0034
(2017/07/19)
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- SCANDIUM EXTRACTION METHOD
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Provided is a method for selectively extracting and inexpensively recovering scandium from an acidic solution containing calcium, magnesium, and scandium. The scandium extraction method according to the present invention involves subjecting an acidic solution containing calcium, magnesium, and scandium to solvent extraction using an extraction agent consisting of an amide derivative represented by the general formula below. In the formula, R1 and R2 represent the same or different alkyl groups, and R3 is a hydrogen atom or alkyl group. The amide derivative preferably consisting of one or more derivatives selected from glycine amide derivatives, histidine amide derivatives, lysine amide derivatives, and aspartic acid amide derivatives. The pH of the acidic solution is preferably pre-adjusted to between 1 and 4.
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Paragraph 0045-0046
(2015/01/07)
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- METHOD FOR SYNTHESIZING RARE EARTH METAL EXTRACTANT
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A rare earth metal extractant containing, as the extractant component, dialkyldiglycol amide acid which is excellent in breaking down light rare earth elements is reacted in diglycolic acid (X mol) and an esterification agent (Y mol) at a reaction temperature of 70° C. or more and for a reaction time of one hour or more such that the mol ratio of Y/X is 2.5 or more, and is subjected to vacuum concentration. Subsequently, a reaction intermediate product is obtained by removing unreacted products and reaction residue, and an aprotic polar solvent is added as the reaction solvent. Then, the reaction intermediate product is reacted with dialkyl amine (Z mol) such that the mol ratio of Z/X is 0.9 or more and the aprotic polar solvent is removed. As a consequence, a rare earth metal extractant is efficiently synthesized at a low cost and at a high yield without having to use expensive diglycolic acid anhydride and harmful dichloromethane.
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Paragraph 0058
(2013/05/08)
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- SYNTHESIS OF RARE EARTH METAL EXTRACTANT
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A rare earth metal extractant in the form of a dialkyl diglycol amic acid is synthesized by reacting diglycolic anhydride with a dialkylamine in an aprotic polar solvent, with a molar ratio of dialkylamine to diglycolic anhydride being at least 1.0, and removing the aprotic polar solvent.
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Page/Page column 3-4
(2012/01/14)
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- SYNTHESIS OF RARE EARTH METAL EXTRACTANT
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A rare earth metal extractant in the form of a dialkyl diglycol amic acid is synthesized by reacting diglycolic anhydride with a dialkylamine in a synthesis medium. A molar ratio (B/A) of dialkylamine (B) to diglycolic anhydride (A) is at least 1.0. A non-polar or low-polar solvent in which the dialkyl diglycol amic acid is dissolvable is used as the synthesis medium.
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Page/Page column 5
(2012/01/14)
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- Hydrolysis and radiation stability of m-xylylene bis-diglycolamide: Synthesis and quantitative study of degradation products by HPLC-APCI +
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For nuclear hydrometallurgical separation process development, it is necessary to demonstrate the stability of the extracting systems, since it is well known that radio- and hydrolytic degradation leads to undesirable effects, such as a decrease in selectivity, poorer phase separation and third-phase formation. Recently, we have developed a new family of bis-diglycolamide (bis-DGA) molecules with high distribution coefficients (D) for EuIII over AmIII. One of these bis-DGA extractants, namely, compound 1, showed high distribution coefficients even under gamma irradiation at 1000 kGy with external 60Co sources. We report herein a detailed account on the stability of 1 against radio- and hydrolysis. We have also identified and quantified the sub-products formed during the irradiation process. Qualitative and quantitative analyses of irradiated 1 were performed by HPLC-MS, indicating the presence of seventeen degradation compounds. All fragments (2-18) were identified and synthesized independently. To complete this study, the An III and LnIII extraction properties of these fragments were assessed under the same experimental conditions as those used to evaluate the AnIII and LnIII extraction by irradiated 1. Despite the significance of a decrease in the concentration of 1, Am/Eu D values are still quite high. This means that at least some degradation products also act as efficient extractants. It is relevant to remark that two of the major degradation products (compounds 3 and 11) are stable to radiation and showed high D values for AmIII and EuIII extraction. Compound 1, an extractant of AmIII and EuIII from nuclear waste, was irradiated with γ irradiation at 1000 kGy with external 60Co sources, resulting in 17 subproducts. These compounds were synthesized and qualitative and quantitative analyses of irradiated 1 were performed. Two of the major degradation products were stable to radiation and showed high D values for AmIII and EuIII extraction. Copyright
- Galan, Hitos,Murillo, Maria Teresa,Sedano, Rosa,Nunez, Ana,De Mendoza, Javier,Gonzalez-Espartero, Amparo,Prados, Pilar
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experimental part
p. 3959 - 3969
(2011/09/15)
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- The C-and N-terminal residues of synthetic heptapeptide ion channels influence transport efficacy through phospholipid bilayers
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The synthetic peptide, R2N-COCH2OCH 2CO-Gly-Gly-Gly-PrO-Gly-Gly-Gly-OR′, was shown to be selective for Cl- over K+ when R is n-octadecyl and R′ is benzyl. Nineteen heptapeptides have now been prepared in which the N-terminal and C-terminal residues have been varied. All of the N-terminal residues are dialkyl but the C-terminal chains are esters, 2° amides, or 3° amides. The compounds having varied N-terminal anchors and C-terminal benzyl groups are as follows: 1, R = n-propyl; 2, R = n-hexyl; 3, R = n-octyl; 4, R = n-decyl; 5, R = n-dodecyl; 6, R = n-tetradecyl; 7, R = n-hexadecyl; 8, R = n-octadecyl. Compounds 9-19 have R = n-octadecyl and C-terminal residues as follows: 9, OR′ = OCH2CH3; 10, OR′ = OCH(CH 3)2; 11, OR′ = O(CH2)6CH 3; 12, OR′ = OCH2-c-C6H11; 13, OR′ = O(CH2)9CH3; 14, OR′ = O(CH2)17CH3; 15, NR′2 = N[(CH2)6CH3]2; 16, NHR′ = NH(CH2)9CH3; 17, NR′2 = N[(CH2)9CH3]2; 18, NHR′ = NH(CH2)17CH3; 19, NR′2 = N[(CH2)17CH3]2. The highest anion transport activities were observed as follows. For the benzyl esters whose N-terminal residues were varied, i.e. 1-8, compound 3 was most active. For the C18 anchored esters 10-14, n-heptyl ester 11 was most active. For the C18 anchored, C-terminal amides 15-19, di-n-decylamide 17 was most active. It was concluded that both the C-and N-terminal anchors were important for channel function in the bilayer but that activity was lost unless only one of the two anchoring groups was dominant. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.
- Djedovic, Natasha,Ferdani, Riccardo,Harder, Egan,Pajewska, Jolanta,Pajewski, Robert,Weber, Michelle E.,Schlesinger, Paul H.,Gokel, George W.
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p. 291 - 305
(2007/10/03)
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