22541-44-2Relevant articles and documents
Ghosh Mazumdar, A. S.,Khandelwal, S. C.,Natarajan, R. P.
, p. 3295 - 3295 (1968)
Crown ethers as actinide extractants in acidic aqueous biphasic systems: Partitioning behavior in solution and crystallographic analyses of the solid state
Rogers,Bauer,Bond
, p. 305 - 312 (1994)
The partitioning behavior of UO22+, Pu4+, Th4+, and Am3+ has been investigated in aqueous biphasic systems formed by the addition of polyethylene glycol of average molecular weight 2000 (PEG-2000) and (NH4)2SO4. Water-soluble crown ethers 18-crown-6 and 15-crown-5 have been utilized as extractants. A positive correlation has been observed between crown ether concentration and metal ion partitioning with DAn decreasing in the order UO22+>Pu4+>Th4+>Am3+. A distribution ratio above unity, however, has only been observed for UO22+ at very high (1.25 M) concentrations of 18-crown-6. In general the distribution ratios for 15-crown-5 are all lower. Matrix ions introduced as NH4NO3, H2SO4, or HNO3 drastically reduce the observed distribution ratios and level the extractant dependencies.
Kinetics of the reaction between plutonium(III) and xenon trioxide
Cleveland
, p. 1302 - 1305 (1967)
The kinetics of the reaction between Pu(III) and XeO3, according to the equation 6Pu(III) + XeO3 + 6H+ → 6Pu(IV) + Xe + 3H2O, have been studied in perchlorate media by following the rate of disappearance of Pu(III) spectrophotometrically at 600 mμ. The rate law for the reaction is: -d[Pu(III)]/dt = k[Pu(III)][XeO3]. The reaction rate is independent of acidity in the 0.5-2 M range. From the variation of the reaction rate with temperature, the following thermodynamic quantities of activation at 25° were calculated: ΔH? = 15.3 ± 2.1 kcal/mole; ΔF? = 20.2 ± 0.1 kcal/mole; ΔS? = -16.0 ± 6.9 eu. The mechanism of the reaction appears to involve either successive one-electron changes or a two-electron change to form a Pu(V) species other than PuO2+, which then reacts with Pu(III) to form Pu(IV).
Cleveland, J. M.
, p. 1816 - 1816 (1965)
Baker, F. B.,Newton, T. W.
, p. 381 - 381 (1959)
Improvement of precision spectrophotometric method with internal reference and its application to analysis of plutonium solutions
Stepanov,Stepanov,Nikitina,Gogoleva,Grigor'eva,Bulyanitsa,Panteleev,Pen'kin,Pevtsova,Domkin
, p. 198 - 203 (2006)
A spectrophotometric precision method with internal reference [1, 2] was applied to analysis of straight Pu solutions for certifying Pu reference materials and for studying the PuO2 solubility in the framework of developing methods for accounting and control of nuclear materials. In the context of the activities mainly concerned with certification of reference materials, a two-channel spectrophotomer and the corresponding technique were further improved in order to decrease the error of the method. This allowed the random component of the relative error of the method to be decreased from 0.1 to 0.04% at the confidence level p = 0.95 and the number of degrees of freedom f = 25. The fixed component of the error of the method was studied in relation to impurities of U, Np and corrosion products of structural materials. Also, the extent of Pu oxidation during sample preparation was studied as influenced by the fluoride ion. The revealed lack of such influence within the limits of the study indicates that the method is suitable for analysis of Pu in mixed solutions. Pleiades Publishing, Inc., 2006.
Connick, R. E.
, p. 1528 - 1528 (1949)
Balakrishnan, P. V.,Ghosh Mazumdar, A. S.
, p. 759 - 759 (1964)
Sonochemical redox reactions of Pu(III) and Pu(IV) in aqueous nitric solutions
Virot, Matthieu,Venault, Laurent,Moisy, Philippe,Nikitenko, Sergey I.
, p. 2567 - 2574 (2015/02/19)
The behavior of Pu(iv) and Pu(iii) was investigated in aqueous nitric solutions under ultrasound irradiation (Ar, 20 kHz). In the absence of anti-nitrous reagents, ultrasound has no effect on Pu(iv), while Pu(iii) can be rapidly oxidized to Pu(iv) due to the autocatalytic formation of HNO2 induced by HNO3 sonolysis. In the presence of anti-nitrous reagents (sulfamic acid or hydrazinium nitrate), Pu(iv) can be sonochemically reduced to Pu(iii). The reduction follows a first order reaction law and leads to a steady state where Pu(iv) and Pu(iii) coexist in solution. The reduction process is attributed to the sonochemical generation of H2O2 in solution. The kinetics attributed to the reduction of Pu(iv) are however higher than those related to the formation of H2O2 which, after several hypotheses, is explained by the sonochemical erosion of the titanium-based sonotrode. Titanium particles thereby generated can be solubilized under ultrasound and generate Ti(iii) as an intermediate species, a strong reducing agent able to react with Pu(iv).
Reduction of Pu(IV) and Np(VI) with carbohydrazide in nitric acid solution
Volk,Marchenko,Dvoeglazov,Alekseenko,Bychkov,Pavlyukevich,Bondin,D'Yachenko
, p. 143 - 148 (2012/08/29)
The reduction of Pu(IV) and Np(VI) with carbohydrazide (NH 2NH)2CO in 1-6 M HNO3 solutions was studied. The Pu(IV) reduction is described by a first-order rate equation with respect to Pu(IV). At [HNO3] ≥ 3 M, the reaction becomes reversible. The rate constants of the forward and reverse reactions were determined, and their activation energies were estimated. Neptunium(VI) is reduced to Np(V) at a high rate, whereas the subsequent reduction of Np(V) to Np(IV) is considerably slower and is catalyzed by Fe and Tc ions. The possibility of using carbohydrazide for stabilizing desired combinations of Pu and Np valence states was examined. Pleiades Publishing, Inc., 2012.
