On the Structure of Highly Hydrolyzed Thorium Salt Solutions.

Magini, M.; Cabrini, A.; Scibona, G.; Johansson, Georg; Sandstroem, Magnus

doi:10.3891/acta.chem.scand.30a-0437

Cited by 32 publications

(25 citation statements)

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“…Despite the good results obtained, there is still room for substantial improvement, especially for sample 1. The main contribution to the residual is the peak at 7.6 ,i ndicated with an asterisk in Figure 3a,w hich does not belong to fluorite ThO 2 .Asimilar feature was previously reported by Magini et al [31] in their investigation of hydrolysedt horium salts. They assigned it to aggregates of oxygen-centred tetrahedra interconnected throughf acet-sharing at an early stage of the synthesis of ThO 2 .I no ur case, the peak could be the result of surface disorder on the 1.0 nm NPs.…”

Section: Resultssupporting

confidence: 81%

“…Small crystallites of ThO 2 have seldom been identified in the precipitates obtainedu nder synthesis conditions compatible with the formationo fa morphous Th IV hydrous oxide. [9,[29][30][31][32] Magini et al [31] investigated hydrolysed thorium salts with wide-ands mall-angle X-ray scatteringa nd found small clusters of atomsa nd microcrystalline ThO 2 particles up to 4nmi n heat-treated solutions at relativelym ild temperatures (below 100 8C). Dzimitrowicz et al [32] observedT hO 2 crystallites of more than 3nmi nX -ray-amorphous precipitatesb yu sing TEM and electron diffraction.…”

Section: Introductionmentioning

confidence: 99%

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The Application of HEXS and HERFD XANES for Accurate Structural Characterisation of Actinide Nanomaterials: The Case of ThO₂

Amidani

Vaughan

Plakhova

et al. 2020

Chemistry A European J

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The structuralc haracterisation of actinide nanoparticles (NPs) is of primary importance and hard to achieve, especially for non-homogeneous samples with NPs less than 3nm. By combining high-energyX-ray scattering (HEXS) and high-energy-resolution fluorescence-detected X-ray absorption near-edge structure (HERFD XANES) analysis,w eh ave characterised for the first time both the short-and mediumrange order of ThO 2 NPs obtained by chemicalp recipitation. By using this methodology,anovel insight into the structures of NPs at different stages of their formation has been achieved. The pair distribution functionr evealed ah igh concentration of ThO 2 small units similart ot horium hexamer clusters mixed with1nm ThO 2 NPs in the initial steps of formation. Drying the precipitates at around1 50 8Cp romoted the recrystallisation of the smallest units into more thermodynamically stable ThO 2 NPs. HERFD XANES analysis at the thorium M 4 edge, ad irect probe for fs tates, showed variations that we have correlated with the breakdown of the local symmetry aroundt he thorium atoms, which most likely concerns surface atoms. To gether,H EXS and HERFD XANES are ap owerful methodology for investigatinga ctinideN Ps and their formation mechanism.

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Section: Resultssupporting

confidence: 81%

Section: Introductionmentioning

confidence: 99%

The Application of HEXS and HERFD XANES for Accurate Structural Characterisation of Actinide Nanomaterials: The Case of ThO₂

Amidani

Vaughan

Plakhova

et al. 2020

Chemistry A European J

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“…If one refers to Table 1, which presents all the results within pH range (2)(3)(4)(5)(6)(7)(8)(9)(10)(11), several anionic mononuclear hydroxo complexes are observed for the lanthanides, namely M(OH) 2+ , M(OH) 3 The Th 4+ cation undergoes hydrolysis to a greater extent than the cations of lanthanides as is evident from the high values of its calculated constants for the above species.…”

Section: Nature Of the Species Formedmentioning

confidence: 89%

“…This is because of exclusively ionic bonds in the latter, whereas the former are known to form covalent bonds using their 5f electrons. Binuclear species with hydroxo bridges as well as polymeric ones have been characterised [10]. Usherenko and Skorik [11] have determined the hydrolysis constants of thorium by potentiometric methods.…”

Section: Thoriummentioning

confidence: 99%

Physicochemical study of the hydrolysis of Rare-Earth elements (III) and thorium (IV)

Bentouhami

Bouet

Meullemeestre

et al. 2004

Comptes Rendus. Chimie

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The present work reports the hydrolysis of ions of the series of lanthanides (III) and actinide (IV) elements in dilute aqueous solutions. It has been systematically examined in the presence of sodium perchlorate, which has been used for maintaining the solution at constant ionic strength. The number, the nature of the species in solution and their hydrolysis constants logb 10i for all ions at I = 0.1 mol dm -3 and at 25°C were determined by different softwares: Superquad and Sirko_P. A pH-potentiometric method was used with glass electrodes to determine the equilibrium constants K i :n+ represents Ce 3+ , Pr 3+ , Nd 3+ , Eu 3+ , Sm 3+ and Th 4+ ions. For the lanthanides, hydrolysis increases with the increase of the atomic number and the contraction of the ionic radius. The Th 4+ ion undergoes significant hydrolysis. To cite this article: E. Bentouhami et al., C. R. Chimie 7 (2004). RésuméCette étude concerne l'hydrolyse des ions de la série lanthanides (III) et du thorium (IV) ; elle a été effectuée en présence de perchlorate de sodium, utilisé pour maintenir constante la force ionique des solutions I, égale à 0,1 mol dm -3 . Le nombre et la nature des espèces en solutions, ainsi que leurs constantes d'hydrolyse logb 10i , ont été déterminées à 25°C à l'aide de différents softwares de calculs, à savoir, Superquad et Sirko_P. Une méthode potentiométrique est utilisée sur électrode de verre pour déterminer les constantes d'équilibres K i :OH) (n−1)+ + H + où M n+ représente les ions Ce 3+ , Pr 3+ , Nd 3+ , Eu 3+ , Sm 3+ et Th 4+ . Pour les lanthanides, l'hydrolyse augmente avec le numéro atomique et la diminution du rayon atomique. On montre que l'ion Th 4+ subit l'hydrolyse de manière significative. Pour citer cet article : E. Bentouhami et al., C. R. Chimie 7 (2004).

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“…Conversely, at the optimum pH (pH"" 6.0), uranium exists mainly as uranyl hydroxide in solution, the solubility of uranium decreases, and the effect of electrostatic repulsive force stays minor; therefore, the maximum uranium uptake is observed. Thorium hydrolysis, however, is more complicated than uranium hydrolysis (18). Indeed, thorium solubility changes dramatically with pH.…”

Section: Effect Of Ph On Uranium and Thorium Adsorptionmentioning

confidence: 99%

Biosorption of Actinides from Dilute Waste Actinide Solution by Egg-Shell Membrane

Ishikawa

Suyama

Satoh

1999

Twentieth Symposium on Biotechnology for Fuels and Chemicals

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Removal of radioactive elements from the effluent and waste aqueous solutions is an important problem. In previous laboratory batch experiments, hen egg-shell membrane (ESM) was stable as an insoluble protein and was very capable of binding heavy metal ions from aqueous solution. Batch laboratory pH profile, time dependency, and capacity experiments were performed to determine the binding of uranium (U) and thorium (Th) to ESM. Batch pH profile experiments indicated that the optimum pH for binding these actinides was approx 6.0 (U) or 3.0 (Th). The adsorption isotherms were developed at pH 5.0 (U) or 3.0 (Th) at 25°C, and the adsorption equilibrium data fitted both Langmuir and Freundlich models. The maximum uptakes by the Langmuir model were about 240 mg U / g and 60 mg Th/ g dry weight ESM. In addition, their adsorption capacities increased as salt concentration increased. ESM could also accumulate uranium from dilute aqueous solution by adjusting to the optimum pH. These results showed that ESM was effective for removing actinides from solution and would be useful in filtration technology to remove actinides from aqueous solution.

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On the Structure of Highly Hydrolyzed Thorium Salt Solutions.

Cited by 32 publications

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The Application of HEXS and HERFD XANES for Accurate Structural Characterisation of Actinide Nanomaterials: The Case of ThO₂

The Application of HEXS and HERFD XANES for Accurate Structural Characterisation of Actinide Nanomaterials: The Case of ThO₂

Physicochemical study of the hydrolysis of Rare-Earth elements (III) and thorium (IV)

Biosorption of Actinides from Dilute Waste Actinide Solution by Egg-Shell Membrane

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On the Structure of Highly Hydrolyzed Thorium Salt Solutions.

Cited by 32 publications

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The Application of HEXS and HERFD XANES for Accurate Structural Characterisation of Actinide Nanomaterials: The Case of ThO2

The Application of HEXS and HERFD XANES for Accurate Structural Characterisation of Actinide Nanomaterials: The Case of ThO2

Physicochemical study of the hydrolysis of Rare-Earth elements (III) and thorium (IV)

Biosorption of Actinides from Dilute Waste Actinide Solution by Egg-Shell Membrane

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The Application of HEXS and HERFD XANES for Accurate Structural Characterisation of Actinide Nanomaterials: The Case of ThO₂

The Application of HEXS and HERFD XANES for Accurate Structural Characterisation of Actinide Nanomaterials: The Case of ThO₂