Highly efficient and selective extraction of Pu(IV) using two alkyl-substituted amides of nitrilo triacetic acid from nitric acid solutions

Role of ligand spacer length of a tripodal amide on uranium(vi) and plutonium(iv) complexation: synthesis, solvent extraction, liquid membrane transport and theoretical studies

“…1), the former has ethylene spacers in its structure which led to completely different distribution ratios of actinides and selectivities. U( vi ), Pu( iv ) and Am( iii ) showed lower distribution ratios at 0.5 M HNO 3 with HONTP compared to those with HONTA 14 (Table 4). Also, the extraction trend reversed for U( vi ) and Am( iii ) extraction.…”

“…However, a marginal increase in the D-values of Pu(IV) was observed in our earlier work with HONTA on irradiation with gamma rays. 14 Gujar et al also reported an increase in the D-value for Pu(IV) extraction with TREN-DGA (a substituted tripodal diglycolamide ligand). 25 Supported liquid membrane studies.…”

“…They display promising results for the extraction of Pu(IV) ions as compared to that of UO 2 2+ and Am(III) ions from nitric acid feed solutions. [12][13][14][15] Out of the different alkyl NTA ligands (alkyl: n-butyl, n-hexyl, n-octyl and n-dodecyl) studied by us, the hexa-n-octyl nitrilotriacetamide (HONTA) ligand was found to be superior for the extraction of tetravalent metal ions from nitric acid medium. However, the spacer length effect of the HRNTA ligands is unexplored.…”

Aggregation Behavior of Nitrilotriacetamide (NTAmide) Ligands in Thorium(IV) Extraction from Acidic Medium: Small-Angle Neutron Scattering, Fourier Transform Infrared, and Theoretical Studies

“…20 The high relative extraction of Pu 4+ compared to U(VI) and Am(III) from 3 M HNO 3 solution was also suggested by others. 7,22,27,32−34 The separation factor of Pu 4+ was found to be greater than10 3 and 5 × 10 3 for UO 2 2+ and Am 3+ , respectively, at 3 M HNO 3 for HONTA 27 dissolved in n-dodecane +10% isodecanol. The distribution ratio of Pu(IV) (D Pu ) in the presence of phase modifiers, for example, isodecanol (IDA), shows a significant decrease from ca.…”

“…Nitrilotriacetamide (NTAmide) ligands, with soft N -donor atoms, have been studied by several authors for the extraction of lanthanide (Ln)/actinide (An) ions for their potential application toward An 3+ /Ln 3+ separation. − However, higher extraction of tetravalent actinide compared to the trivalent or hexavalent actinides by NTAmide was also reported by others. − The involvement of the central nitrogen of the NTAmide in the extraction of softer trivalent actinides was suggested by Bhattacharyya et al, , whereas interaction of amidic oxygen of lignad for tetravalent ion extraction was shown by Huang et al The long alkyl chain derivatives of NTAmide , such as the one with n -octyl groups (HONTA­( L II ), Figure ), show high extraction ability and selectivity for Th­(IV) compared to trivalent Ln ions from pH 1 to 10.0 M HNO 3 with separation factors ( SF Th – Ln = D Th / D Ln ) ranging from 2.5 × 10 2 to 10 3 . The high relative extraction of Pu 4+ compared to U­(VI) and Am­(III) from 3 M HNO 3 solution was also suggested by others. ,,,− The separation factor of Pu 4+ was found to be greater than10 3 and 5 × 10 3 for UO 2 2+ and Am 3+ , respectively, at 3 M HNO 3 for HONTA dissolved in n -dodecane +10% isodecanol. The distribution ratio of Pu­(IV) ( D Pu ) in the presence of phase modifiers, for example, isodecanol (IDA), shows a significant decrease from ca.…”