JRP CALL information
Supported By

European Commission

Short description of the work

The aim of these EXAFS measurements is to determine the nature of uranium (VI) species extracted in an ionic liquid (IL) by two kinds of extractant molecules: a neutral malonamide-base extracting molecule (DMDBMA) and an ionic liquid functionalized with a CMPO group (FIL-CMPO), from acidic aqueous solutions (HNO3 or HClO4). The extraction of charged complexes, instead of neutral complexes formed in the usual organic solvents, was postulated from our previous experimental. We now want to determine experimentally the structure of extracted uranyl species, i.e. the stoichiometry, ligands nature and number.
During the allocated beam time, we have analysed 15 samples at the uranium L3 edge in transmission and fluorescence detection. 8 solutions are reference samples containing a known [extractant molecule]/[NO3- or ClO4-]/[UO22+] ratio, the others were obtained by liquid liquid extraction of uranium in different experimental conditions (nature and concentration of the acid, nature of the extractant molecule).
The preliminary analysis of the spectra show that uranyl is extracted as a bivalent cationic complex at low acidic concentration, whatever the extraction molecule. Using DMDBMA, the nature of the extracted species in the IL phase changes when the aqueous acidic concentration increases, but this is not the case when the extraction is made using the FIL-CMPO molecule. A precise data analysis will allow us to determine precisely the nature of those complexes, and thus, determine the mechanism leading to their extraction in the studied ionic liquid.

Main visitor contact data
Name: Dr Clotilde Gaillard
Organisation: CNRS-IPNL

JRP Identification
JRP nr: TALI-C03-06
JRP title: Characterization of RTIL U(VI) complexes
JRP scope: Scope 1: Actinide separation chemistry

Visited Associated Pooled Facility
Visited APF during the stay: HZDR - ROBL
Name of the APF Contact Person: Dr Christoph Hennig

Other APF and organisation involved in the JRP
Other organisations involved: CNRS - Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg (Maria Boltoeva, Isabelle Billard, Ali Ouadi)
Other APF involved in the project:

Description of the work done at the associated pooled facility
Start date of the stay: 10/24/2014
End date of the stay: 10/28/2014
Quantity of access: 11
Access Unit: Shifts
Misc.: Work during week-ends