New Ionic Liquid Based on the CMPO Pattern for the Sequential Extraction of U(VI), Am(III) and Eu(III)

Dariia Ternova (1) , Ali Ouadi (1) , Valérie Mazan (1) , Sylvia Georg (1) , Maria Yu Boltoeva (1) , Vitaly Kalchenko (2) , Stanislas Miroshnichenko (2) , Isabelle Billard (3) , Clotilde Gaillard (4, 5)

1 IPHC - Institut Pluridisciplinaire Hubert Curien
2 Institute of Organic Chemistry of NASU [Kyiv]
3 LEPMI - Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces
4 IPNL - Institut de Physique Nucléaire de Lyon
5 ACE

Extraction of U(VI), Eu(III) and Am(III) has been performed from acidic aqueous solutions (HNO 3 , HClO 4) into the ionic liquid [C 4 mim][Tf 2 N] in which a new extracting task-specific ionic liquid, based on the CMPO unit {namely 1-[3-[2-(octylphenylphosphoryl) acetamido]propyl]-3-methyl-1H-imidazol-3-ium bis(trifluoromethane)sulfonamide, hereafter noted OctPh-CMPO-IL}, was dissolved at low concentration (0.01 molÁL-1). EXAFS and UV-Vis spectroscopy measurements were performed to characterize the extracted species. The extraction of U(VI) is more efficient than the extraction of trivalent Am and Eu using this TSIL, for both acids and their concentration range. We obtained evidence that the metal ions are extracted as a solvate (UO 2 (OctPh-CMPO-IL) 3) by a cation exchange mechanism. Nitrate or perchlorate ions do not play a direct role in the extraction by being part of the extracted complexes, but the replacement of nitric acid for perchloric acid entails a drop in the selectivity between U and Eu. However, our TSIL allows a sequential separation of U(VI) and Eu/Am(III) using the same HNO 3 concentration and same nature of the organic phase, just by changing the ligand concentration.

Mots clés: Uranyl; Solvent extraction; Ionic liquids; Europium(III); Americium(III); Carbamoylmethylphosphine oxide

Domaines: Radiochimie; Génie chimique

Dariia Ternova, Ali Ouadi, Valérie Mazan, Sylvia Georg, Maria Yu Boltoeva, et al.. New Ionic Liquid Based on the CMPO Pattern for the Sequential Extraction of U(VI), Am(III) and Eu(III). Journal of Solution Chemistry, 2018, 47 (8), pp.1309-1325. ⟨10.1007/s10953-018-0730-3⟩. ⟨hal-02271283⟩