Synergic extraction of lanthanoids(III) with thenoyl trifluoroacetone and terpyridine

The synergic extraction of trivalent lanthanoids (Ln: La, Nd, Sm, Eu, Yb and Lu) with 2-thenoyltrifluoroacetone (Htta) and 2,26, 2-terpyridine (tpy) into benzene has been studied. The partition coefficient (P_s) of tpy was obtained experimentally in order to calculate the equilibrium concentration of tpy in the organic phase. From the slope analysis, it was shown that these lanthanoids were extracted as Ln(tta)₃(tpy). The adduct formation constant (_s,1) and the synergic extraction constant were obtained for each lanthanoid. The (_s,1) decreases with increasing atomic number of lanthanoids and the trend of (_s,1) is compared with that for bidentate and unidentate heterocyclic amines.     

Synergic extraction of uranium(VI) by combination of tri-iso-octylamine and neutral donors

Synergistic effect of neutral donors like tri-butyl phosphate (TBP), triphenyl phosphine oxide (TPPO), trioctyl phosphine oxide (TOPO), and dimethyl sulphoxide (DMSO) on the extraction of uranium(VI) by tri-isooctyl amine into CCl₄ is reported. Synergistic coefficients and adduct formation constants are calculated from distribution data and correlated with relative donor abilities of added bases.     

Synergic extraction of cobalt(II) with mixtures of 4-methyl-N-8-quinolinylbenzene sulphonamide and neutral organophosphorus compounds

The distribution equilibria of cobalt(II) with 4-methyl-N-8-quinolinylbenzene sulphonamide in the presence of tributylphosphate or trioctylphosphine oxide dissolved in toluene were studied as a function of hydrogen ion concentration and the concentration of the organophosphorus compounds. Evaluation of the extraction data made it possible to deduce the stoichiometry of the extracted species, determine their corresponding extraction constants and quantify the synergic effect.     

Solvent extraction of uranium(VI) by LIX-54 and its mixtures

Studies on solvent extraction of uranium(VI) by a commercially available chelating extractant LIX-54 (a -diketone derivative) (HA) and its mixtures with tri-n-butyl phosphate (TBP) in benzene diluent show quantitative extraction by a mixture of 5% LIX-54 and 5% TBP at pH 4.3. Influence of different proportions of LIX-54 or TBP in the mixtures on the extraction of the same metal ion has been studied. Pronounced synergism has been observed. The composition of the extracted species seems to be [UO₂(OH)(A)(HA)(TBP)] as determined from slope analysis. Slopes of the linear plots were computed employing regression analysis and variance in results has been shown.     

Mutual binary separations of cadmium(II), indium(III) and thallium(III) as chlorides by their extraction in high molecular weight amines

The extraction of cadmium(II), indium(III) and thallium(III) with high molecular weight amines have been studied from aqueous hydrochloric acid solutions. Using the data mutual binary separations of these three elements with high separation coefficients are proposed. Various variables like type of amine, amine concentration and organic diluent were explored to propose the best conditions of separations.     

Synergistic extraction of manganese(II) with thenoyltrifluoroacetone and neutral unidentate and bidentate ligands

Tritium content in tritiated titanium was measured by the method of fluorescent X-ray detection with an intrinsic Ge detector. The conventional method of setting region-of-interest of overlapped X-ray peaks was developed. The Ti K and K X-ray peak profile of³H/Ti was compared with that of V-49 electron capture standard source. Effect of geometry and sample thickness on peak profile was discussed. Detection limit in this method was 0.187 GBq of tritium.     

Synergic effects in the extraction of paracetamol from aqueous NaCl solution by the binary mixtures of diethyl ether and low molecular weight primary alcohols

Liquid-liquid extraction of paracetamol from aqueous NaCl solutions was performed with diethyl ether, 1-propanol, 1-butanol, isobutanol, 1-pentanol, and binary mixtures diethyl ether/1-propanol, diethyl ether/1-butanol, and diethyl ether/isobutanol. Among the pure solvents investigated in this study best extraction efficacy was obtained with 1-butanol. Synergic effects in the extraction with binary mixtures was investigated and compared with some other systems used for the extraction of poorly extractable compounds. Results obtained in this study may be of both fundamental and practical importance.     

Liquid-liquid extraction of molybdenum(VI) and uranium(VI) by LIX 622

The order of extraction of Mo(VI) from 1M acid solutions by 5% (v/v) LIX 622 (HL) in benzene is HCl>HNO₃>HClO₄>H₂SO₄, and extraction decreases with increasing concentration of HCl and H₂SO₄, and increases slightly with increasing concentration of HNO₃ and HClO₄. The extracted species is shown to be MoO₂L₂ as established by IR data of organic extracts and the extracted species in the solid form. Extraction is almost quantitative at and above 10% LIX 622, and is found to be independent of [Mo(VI)] in the range of 10^–4 to 10^–3 M. The diluents CCl₄, CHCl₃ and C₆H₆ are found to be superior to solvents of high dielectric constant for extraction of Mo(VI). Extraction of uranium(VI) by 10% (v/v) LIX 622 in benzene was found to increase with increasing equilibrium pH (3.0 to 6.0), and becomes quantitative at pH 5.9. Tributyl phosphate acts as a modifier up to 2% (v/v). Thorium(IV) is almost not extracted by LIX 622 or its mixture. Separation of Mo(VI) and U(VI) is feasible.     

Extraction of zinc thiocyanate complexes by high molecular weight amines and quaternary ammonium salt

The extraction of Zn(II) thiocyanate complexes by various high molecular weight amines and quaternary ammonium salts has been studied. The extraction efficiency of various amines and the dependence of extraction on thiocyanate concentration, pH of the aqueous phase and on metal and amine concentration have been investigated. An attempt has also been made to identify the extracted species by extraction isotherms and log-log plots of amine concentration vs distribution ratio.     

Precise molecular weight distributions of high polymers by semiautomatic solvent extraction

It has been found practical to fractionate relatively monodisperse polystyrenes of molecular weights up to 4 × 10⁶ by using a semiautomatic solvent extraction procedure. The fractionators consist of flow-through mixing chambers provided with settling regions for the removal of finely suspended solid material. Provision is made for accurate control of both temperature and solvent–nonsolvent ratio. Two such apparatus, operated in tandem, were used in the present work; in principle, several more stages could be employed if desired for most polymer systems. Results on polystyrenes prepared in well defined ways appear to be in good agreement with predicted distributions. Applicability to other polymer systems is discussed.     

Synergistic effect of heterocyclic bidentate amines on the extraction of thorium(IV) with 2-thenoyltrifluoroacetone

The synergistic effect on the extraction of thorium(IV) was found by the combination of 2-thenoyltrifluoroacetone (Htta) and 1,10-phenanthroline (phen) or 4,7-diphenyl-1,10-phenanthroline (dpp) as a neutral bidentate ligand. Especially in the presence of dpp (1·10^–3M) in benzene, the distribution ratio of thorium(IV) increased by a factor of about 300. Such synergistic enhancement of the extraction was ascribed to the formation of the adduct complex of Th(tta)₄(phen) and Th(tta)₄(dpp) in the organic phase. The extraction constant and the adduct formation constant were determined and discussed.     

Extraction of tetravalent berkelium by high molecular weight amines in the presence of heteropolyanions

A rapid and simple method for the determination of selenium in biological and environmental samples by thermal neutron activation analysis, employing substoichiometric solvent extraction of Se/IV/ with 2-mercaptobenzothiazole /2-HMBT/ from 5. 7M HCl solution into chloroform has been developed.     

Extraction of rare earth elements by high molecular weight amines from nitric acid solutions

Extraction of trivalent rare earth elements by a high molecular weight primary amine /decylamine/ from 0.5–3M nitric acid solutions, containing potassium phosphotungstate /K₁₀P₂W₁₇O₆₁/, has been investigated. The effect of nitric acid and potassium phosphotungstate concentration of the organic solvent, and lanthanides ionic radii upon distribution coefficients has been studied. It has been established that decylamine solutions in chloroform can be used for the group isolation of rare earth elements and for their separation.     

Preparation of high molecular weight poly(vinylaniline)

For the first time, we believe, a high molecular weight soluble poly(vinylaniline) has been prepared. This was done by a bead polymerization with exclusion of oxygen. The polymer has little or no color and good stability in solution.     

Extraction of Mn(II), Co(II), Cr(III) and Fe(III) from succinic acid medium by high molecular weight amines

The extraction behavior of Mn(II), Co(II), Cr(III) and Fe(III) has been studied in high molecular weight amines from succinic acid medium. The effect of different variables, like, type of amine, effect of pretreatment of amine with various acids, type of diluent and concentration of metal, succinate, hydrogen ions and amine, has been investigated. Extraction of Cr(III) and Fe(III) species is proposed and some binary separations achieved.     

Extraction of rare earth elements by primary high molecular weight amines from hydrochloric acid solutions

Extraction of trivalent lanthanides: La, Ce, Nd, Eu, Tb, Tm, Yb by primary high molecular weight amines from 0.5–3M hydrochloric acid solutions, containing complex-forming agent potassium phosphotungstate /K₁₀P₂W₁₇O₆₁/ has been investigated. The effect of hydrochloric acid, potassium phosphotungstate and amine concentration, the length of primary amine alkyl chain, organic solvents nature and elements ionic radii on distribution coefficients have been studied. It has been established that the system can be used for group isolation and separation of rare earth elements.     

Synergic extraction and spectrophotometric determination of titanium(IV)

A method has been developed for the synergic extraction and spectrophotometric determination of Ti(IV) with N-hydroxy-NN'-diphenylbenzamidine and thiocyanate. The yellow ternary complex, extracted into chloroform from dilute sulphuric acid medium (pH = 1.5+/-0.1), has maximum absorbance at 390 nm (molar absorptivity 1.3 x 1O(4) 1.mole(-1). cm(-1)). The method is free from interference from a large number of foreign ions and is recommended for the determination of titanium in steel.     

Thermal decomposition of the solvent-extracted metal complexes with high molecular weight amines

Organic solutions from the extractions of divalent manganese, cobalt, copper and zinc, trivalent gallium, indium and thallium, tetravalent vanadium and zirconium, and hexavalent uranium and molybdenum with trioctylamine (TOA, R₃N) and trioctylmethylammonium chloride (TOMAC, R₃R′NCl) in benzene were heated in vacua to prepare benzene-free complexes. The resulting complexes were examined by thermogravimetry and differential thermal analysis under an atmosphere of nitrogen, and their thermally decomposed products, such as volatile matters and residues, by gas chromatography, X-ray diffraction and infrared spectroscopy. Consequently, the thermal decomposition process of these complexes is discussed and the structure of the complexes is proposed on the basis of the results obtained.     

Synergic extraction of Eu(III) and Tb(III) by 2-thenoyltrifluoroacetone and tribenzylamine

Synergic extraction of Eu(III) and Tb(III) with 2-thenoyltrifluoroacetone (HTTA) and tribenzylamine (TBA) as neutral donor ligand has been studied in chloroform from perchlorate media at lower pH range. The stoichiometric composition of the adduct was established as M(TTA)₃ · 3TBA for both the elements, having a coordination number 9. The formation constants K_3,0 and K_3,3 and stability constant _3,3 of the organic phase reaction have been calculated. The effect of temperature on the extraction has also been studied. The adducts are stabilized by the large exothermic enthalpy change. The calculated thermodynamic functions such as H, S and G were used to elucidate the mechanism of synergism in which the coordination numbers of the lanthanide ions increased.     

Synthesis of high molecular weight and narrow molecular weight distribution poly(acrylonitrile) via RAFT polymerization

Well‐defined polyacrylonitrile (PAN) of high viscosity‐average molecular weight (M_η = 405,100 g/mol) was successfully synthesized using reversible addition‐fragmentation chain transfer polymerization. The polymerization exhibits controlled characters: molecular weights of the resultant PANs increasing approximately linearly with monomer conversion and keeping narrow molecular weight distributions. The addition of 0.01 equiv (relative to monomer acrylonitrile) of Lewis acid AlCl₃ in the polymerization system afforded the obtained PAN with an improved isotacticity (by 8%). In addition, the influence of molecular weights and molecular weight distributions of PANs on the morphology of the electrospun fibers was investigated. The results showed that, under the same conditions of electrospinning, average diameter (247–1094 nm) of fibers increased with molecular weights of PANs, and it was much easier to get “uniform” diameter fibers while using PANs with narrow molecular weight distributions as the precursor of electrospinning. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013