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N,N-Dialkyl diglycolamic acid (HDRDGA) derivatives with alkyl groups varying from n-hexyl to n-dodecyl were synthesized, and the promising ligands such as N,N-dioctyl diglycolamic acid (HDODGA) and N,N-didecyl diglycolamic acid (HD2DGA) were investigated for the mutual separation of trivalent lanthanides and actinides from dilute nitric acid solution. Since diglycolamic acid is strongly polar, it was dissolved in a traditional diluent, n-dodecane, with the help of an isodecyl alcohol (IDA) phase modifier. Nevertheless, the hexyl and didodecyl derivatives were sparingly soluble even in the presence of 30% (v/v) IDA in n-dodecane, and therefore, the extraction behavior of the lanthanide and actinide representatives, Eu(III) and Am(III), respectively, was studied only in a solution of HDODGA or HD2DGA present in 30% (v/v) IDA/n-dodecane. The cation-exchange mechanism of extraction and the stoichiometry of trivalent metal to HDRDGA were elucidated from the slope analysis of the extraction data. Since the stoichiometry of the metal to ligand complex in the organic phase was unusually varied from 1 : 3 to 1 : 6 depending upon the Nd(III) loading into the organic phase, the reverse micellar aggregation behavior and the coordination chemistry of Nd(III) in the organic phase were probed by dynamic light scattering and visible spectroscopy, respectively. The results revealed that three molecules of anionic DRDGA were coordinated to Nd(III) in the inner-sphere at lower metal concentrations, and also three more molecules of HDRDGA in the outer-sphere at higher metal concentrations. The good separation factor achieved with the use of these ligands showed their potential ability to separate lanthanides from actinides in nitric acid medium. [ABSTRACT FROM AUTHOR]

N,N-dihexyloctanamide (DHOA) is being considered as a promising extractant in the aqueous reprocessing of spent nuclear fuels. In view of rise in temperature of the solvent during reprocessing of fast reactor fuel, the present study aimed at evaluating the physical properties such as density, viscosity, and interfacial tension and Pu(IV) extraction behavior in 1.1 M DHOA/n-dodecane as a function of temperature and duration of heating. The influence of nitric acid in altering the physical properties with respect to temperature was evaluated. Physical properties and extraction behavior of the solvent changed to a remarkable extent with temperature. Quantitative amount of Pu(IV) could be back-extracted from loaded, solvent in three contacts at 313 K. FT-IR studies were carried out to evaluate the thermal stability of the solvent. Thus, the performance of the solvent, 1.1 M DHOA/n-dodecane is satisfactory at higher temperatures also. [ABSTRACT FROM AUTHOR]

Various diglycolamides (DGAs),N,N,N’,N’-tetraoctyl diglycolamide (TODGA),N,N-di-2-ethylhexyl-N’,N’-di-octyl diglycolamide (DEHDODGA),N,N,N’,N’-tetra-2-ethylhexyl diglycolamide (TEHDGA),N,N-di-decyl-N’,N’-di-hexyl diglycolamide (D2DHDGA),N,N-di-butyl-N’,N’-di-dodecyl diglycolamide (DBD3DGA),N,N,N’,N’-tetra-hexyl diglycolamide (THDGA), andN,N,N’,N’-tetradecyl diglycolamide (TDDGA) have been synthesized and studied for the extraction of Am(III) and Eu(III) from nitric acid medium. An attempt was made to understand the extraction and third phase formation behavior of trivalent metal ions in these DGAs. Our results revealed that despite having the same carbon to oxygen ratio in these DGAs, the third phase formation behavior and extractions achieved in these DGAs are significantly different. [ABSTRACT FROM AUTHOR]