scholarly journals The interphase distribution of light REE Ce(III) and La(III) in system based on PEG-1500 – NaNO3 – H2O with the quaternary ammonium base addition

2022 ◽  
Vol 1212 (1) ◽  
pp. 012023
Author(s):  
A V Levina ◽  
A Ya Fedorov ◽  
M I Fedorova

Abstract The problem of e-waste processing and recovery of valuable metals from such waste for the second use is attracting more and more scientists’ attention. Liquid extraction as one of hydrometallurgy steps is a traditional method for the metal recovery. However, application of solvent extraction is not meet the green chemistry principles due to organic solvents. Aqueous two-phase systems based on water-soluble polymers are promising alternative for hazardous organic solvents. In this work the dependencies of Ce(III) and La(III) distribution coefficients from process time and the initial quaternary ammonium base concentration have been achieved. Also, based on the Ce(III) and La(III) extraction isotherms it has been shown that the metals initial concentrations are highly affects the distribution coefficients of studied metals. The possibility of aqueous two-phase system application as a solvent for quaternary ammonium salt for light REE (Ce(III) and La(III)) extraction from water solution has been shown.

1997 ◽  
Vol 488 ◽  
Author(s):  
P. J. Kinlen ◽  
Y. Ding ◽  
C. R. Graham ◽  
J. Liu ◽  
E. E. Remsen

AbstractA new emulsion process has been developed for the direct synthesis of the emeraldine salt of polyaniline (PANI) that is soluble in organic solvents. The process entails forming an emulsion composed of water, a water soluble organic solvent (e.g., 2-butoxyethanol), a water insoluble organic acid (e.g., dinonylnaphthalene sulfonic acid) and aniline. Aniline is protonated by the organic acid to form a salt which partitions into the organic phase. As oxidant (ammonium peroxydisulfate) is added, PANI salt forms in the organic phase and remains soluble. As the reaction proceeds, the reaction mixture changes from an emulsion to a two phase system, the soluble PANI remaining in the organic phase. With dinonylnaphthalene sulfonic acid (DNNSA) as the organic acid, the resulting product is truly soluble in organic solvents such as xylene and toluene(not a dispersion), of high molecular weight (Mw >22,000), film forming and miscible with many polymers such as polyurethanes, epoxies and phenoxy resins. As cast, the polyaniline film is only moderately conductive, (10−5 S/cm), however treatment of the film with surfactants such as benzyltriethylammonium chloride (BTEAC) or low molecular weight alcohols and ketones such as methanol and acetone increases the conductivity 2–3 orders of magnitude.


2008 ◽  
Vol 73 (3) ◽  
pp. 341-350 ◽  
Author(s):  
Laura Bulgariu ◽  
Dumitru Bulgariu

The extraction of Cd(II) was studied in an aqueous PEG-(NH4)2SO4 two-phase system, formed from a water-soluble polymer (poly(ethylene glycol), PEG) and an inorganic salt ((NH4)2SO4), in the presence of halide ions. In the absence of a suitable extracting agent, Cd(II) remains predominantly in the salt-rich phase of the extraction system. By addition of halide ions as extractants, Cd(II) is extracted into the PEG-rich phase due to the formation of cadmium halide species. The efficiency of the extractants increased in the order: Cl- < Br- < I-. From the distribution coefficients determined as a function of the concentration of the halide ions, the compositions of the extracted species were assumed and the "conditional" extractions constants calculated. The experimental results indicate that the extractability of Cd(II) in such extraction systems depends on the type of Cd(II) halide species (which is mainly determined by the acidity of salt stock solution) and of their stability.


1976 ◽  
Vol 59 (5) ◽  
pp. 1051-1058 ◽  
Author(s):  
Bozidar Stavrić ◽  
Raymond Klassen ◽  
W Arnold

Abstract Thirteen saccharin samples used for carcinogenicity tests in animals in various laboratories were analyzed for their chemical purity. Although most of the impurities were water-soluble, some were mainly soluble in organic solvents. These impurities were extracted with chloroform-methanol from a water solution of sodium saccharin. Samples obtained as acid-saccharin were converted to the sodium form before extraction. The major impurity in commercial saccharin, o-toluenesulfonamide, was also soluble in this system. Impurities were separated by gas-liquid chromatography of the underivatized, concentrated extract. Eleven major, well separated peaks were collected from the gas chromatographic column and identified by mass spectroscopy. Some of the peaks were compared with known standards. Qualitative and quantitative differences in impurities were observed among different saccharin samples. The identified impurities (in order of appearance from the gas-liquid chromatographic column) were as follows: o-toluenesulfonamide; p-toluenesufonamide; 1,2-benzisothiazole 1,1-dioxide; 1,2-benzisothiazoline 1,1-dioxide; diphenylsulfone; o,o′-ditolylsulfone; o,m′-ditolylsulfone, o,p′-ditolylsulfone; m,p′-ditolylsulfone; p,p′-ditolylsulfone, and tetracosane.


1990 ◽  
Vol 12 (12) ◽  
pp. 950-954 ◽  
Author(s):  
Evgeni N. Vulfson ◽  
Rooma Patel ◽  
Jean E. Beecher ◽  
Anthony T. Andrews ◽  
Barry A. Law

1951 ◽  
Vol 35 (1) ◽  
pp. 55-65 ◽  
Author(s):  
V. G. Dethier

Rejection thresholds of eight primary alcohols applied to the tarsal chemoreceptors of the blowfly Phormia regina Meigen and the ovipositor of Gryllus assimilis Fab. have been determined. Three different solvents for the alcohols have been used: water, ethylene glycol, and mineral oil. The comparative stimulating effectiveness of the alcohols assumes a different aspect with each different solvent. In oil the range of thresholds from methanol to octanol extends over less than one log unit as compared with the corresponding thresholds in water which extend over four log units. In glycol the thresholds extend over two and one half log units only. When water is employed as a solvent, the line which describes the relationship between threshold concentration and chain length of the compound exhibits a sharp break at or near butanol. No such discontinuity is evident when glycol or oil is employed as solvent. This is offered as evidence supporting the hypothesis that the limiting mechanism in tarsal chemoreception involves a two phase system whereby highly water-soluble compounds gain access to the receptor through an aqueous phase and the larger lipoid-soluble molecules chiefly through a lipoid phase. Additional facts which support this idea are gained from data which show that the inflection in the curve occurs at different points with different species of insects and is conspicuously absent in the case of man. When thresholds in aqueous solutions are converted from molar concentrations to activities, it is clear that the relation of equal physiological effect at equal thermodynamic activities does not apply here. The lower members of the series stimulate at progressively increasing activities up to pentanol and then at progressively decreasing activities. Furthermore, the ratio of water threshold to oil threshold exhibits no obvious agreement with the water/oil partition coefficients determined experimentally. These results indicate either that the limiting process of chemoreception in these insects does not depend upon the establishment of an equilibrium or that some kinetic effect is obscuring an underlying relationship which does so depend.


1994 ◽  
Vol 49 (11) ◽  
pp. 1511-1524 ◽  
Author(s):  
David J. Brauer ◽  
Jörg Fischer ◽  
Stefan Kucken ◽  
Klaus P. Langhans ◽  
Othmar Stelzer ◽  
...  

Primary and secondary aminoalkylphosphanes R2N-(CH2)m-PH2 (R2 = Me2, nBu2, C5H10, C4H8O, 2-(1-Methyl-2-pyrrolidinyl); m = 2, 3, 6, 10, 11; 1-6) or [R2N-(CH2)m]2PH (7, R2 = C5H10; m = 2) are accessible by aminoalkylation of PH3 with ω̃ -chloroalkylamines R2N-(CH2)m-Cl in the superbasic medium DMSO/KOH (DMSO = dimethylsulfoxide). By selective N-quaternization of 1, 2, 4-6 with R'I (R' = Me, CnH2n+1; n = 6-8, 12, 16, 18) in the two-phase system CH2Cl2/H2O novel primary phosphanes [R'R2N-(CH2)m-PH2]+I- (11-16f) with quaternary ammonium groups in the alkyl side chain are obtained. The water solubility of 11-16f decreases with increasing chain length (n) of R′ 11 (R = R' = Me; m = 2) shows a trans conformation at the C2H4 bridge according to an X-ray structural analysis. Protonation of 1, 2, 4, 5 with HCl affords the water-soluble hydrochlorides [HR2N-(CH2)m-PH2]+Cl- (19-22). The cationic primary phosphanes 11-16f are stable towards oxygen. By oxidation of 11 with one or two equivalents of H2O2 the primary phosphane oxide [Me3N-(CH2)2-P(O)H2]+I- (23) or the phosphonous acid [Me3N-(CH2)2- P(O)(OH)H]+I- (23a) are formed. Hofmann degradation of 11 or 16c with KOH yields phosphirane in good yields. Reaction of 1, 2, 4-6 (L) with Fe2(CO)9 at ambient temperature yields stable complexes (CO)4FeL (26-30). Under more rigorous conditions Fe3 clusters (31, 32) with free R2N groups are obtained.


2021 ◽  
Author(s):  
Xiaowang Zhang ◽  
Zhuotao Tan ◽  
Chaojian Li ◽  
Siyu Qi ◽  
Mengjiao Xu ◽  
...  

Abstract Background: Lactones are important compounds in the field of medicine, material and chemical industry. One of the promising accesses to these flexible scaffolds is NAD(P)+-dependent alcohol dehydrogenases-catalyzed oxidative lactonization of diols, which relies on the construction of an efficient NAD(P)+ regeneration system. Results: In this study, a novel system combining horse liver alcohol dehydrogenase (HLADH) with the synthetic bridged flavin cofactor was established for biosynthesis of lactones. The reaction conditions of this system were optimized and a variety of lactones including chiral lactones were efficiently obtained from various diols. Compared to the previously reported NAD(P)+-regeneration systems, this system showed better regeneration efficiency and product yield. A two-phase system was further applied to solve the problem of product inhibition, and 80% yield was obtained at the condition of 300 mM substrate.Conclusions: This study provides an efficient method to synthesis of lactones from diols under mild conditions. We believe this system will be a promising alternative to promote the synthesis of other valuable compounds.


2011 ◽  
Vol 236-238 ◽  
pp. 49-53
Author(s):  
Shao Peng Liu ◽  
Zhi Min Zong ◽  
Shan Shan Zhang ◽  
Yue Xu ◽  
Gui Zhen Gong ◽  
...  

This paper was aimed to study the aqueous two phase extraction (ATPE) on water soluble bio oil(SBO), in which ethanol, K2HPO4, NaH2PO4and (NH4)2SO4were selected to form the water soluble bio oil(SBO) aqueous two phase system (ATPS). After phase separation, the extraction rates and the volume ratios of the upper to lower layer of the ATPSs were investigeted. Both the upper and lower layers of these SBO ATPSs were analyzed by elemental analyzer and Fourier transformation infrared spectrometer (FTIR). The different extraction rates indicates the influnces of different salt during the phase saperation, of which NaH2PO4has less effect to SBO than the other two; K2HPO4may neutralize some organic acid; the lowest extraction rate of ethanol/(NH4)2SO4system indicates the effects of (NH4)2SO4to SBO. Too much ethanol will fech in more water, hence the optimizational ratio of the SBO ATPS should be SBO:salt:ethanol=10:10:5. In element analysis, the diclining of oxygen in all the upper layers and the increasing of nitrogion in both layers of (NH4)2SO4system indicates the abbility of the less oxygen components concentration of the ATPS and the reaction between (NH4)2SO4and SBO. According to FTIR test, the lack of absorption at 1515cm-1of all the lower layers indicates the completely transforming of phenols into the upper layers. Because of the high extraction rate and less influence to SBO, ethanol/NaH2PO4system may be the most suitable ATPS for SBO extraction.


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