1
|
Gujar RB, Verma PK, Bhattacharyya A, Mohapatra PK, Egberink RJM, Huskens J, Verboom W. Effect of branching in the alkyl chain of diglycolamide on the sequestration of tetravalent actinides: solvent extraction and theoretical studies. Dalton Trans 2024. [PMID: 39257215 DOI: 10.1039/d4dt02176b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
DGA (diglycolamide) ligands show a different extraction behavior of trivalent metal ions by changing the branching alkyl chain length as well as the branching at the methylene position. There are no studies of these factors on the extraction efficiency of these DGA derivatives for the extraction of tetravalent actinides. We have evaluated four different DGA derivatives for the extraction of Np, Pu, and Th from molecular diluents. The n-butyl derivative shows enhanced extraction efficiency and branching gives rise to a reduction in the extraction efficiency of tetravalent ions. The distribution ratios are higher in pure octanol than in a mixture of 30% octanol and 70% n-dodecane. This behavior is in marked difference to that of the extraction of trivalent ions where the addition of an alcohol generally decreases the distribution ratio of trivalent ions due to the ligand-modifier intercation, poor aggregation or micelle formation tendency of DGAs in polar solvents. This suggests that micelle-mediated extraction may not be the dominating factor for the extraction of tetravalent metal ions. Slope analysis suggests the involvement of only two DGA molecules in the extracted species suggesting no/poor possibility of micelle formation in the present system. The higher extraction in pure octanol may be due to a better solubility of the extracted complexes in this polar medium compared to the mixture of octanol and n-dodecane. The water and acid uptake, the back extraction, and the radiation stability of the solvent systems were also investigated. DFT studies were performed to get a better insight into the extraction and complexation of the different DGA solvent systems.
Collapse
Affiliation(s)
- Rajesh B Gujar
- Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai - 400 085, India.
| | - Parveen K Verma
- Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai - 400 085, India.
| | | | - Prasanta K Mohapatra
- Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai - 400 085, India.
| | - Richard J M Egberink
- Laboratory of Molecular Nanofabrication, Department for Molecules @ Materials, MESA+ Institute, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
| | - Jurriaan Huskens
- Laboratory of Molecular Nanofabrication, Department for Molecules @ Materials, MESA+ Institute, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
| | - Willem Verboom
- Laboratory of Molecular Nanofabrication, Department for Molecules @ Materials, MESA+ Institute, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
| |
Collapse
|
2
|
Rout A, Mishra S. Ligand Effect on Physicochemical Properties of Ionic Liquid. Chemphyschem 2023; 24:e202200802. [PMID: 36631955 DOI: 10.1002/cphc.202200802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/11/2023] [Accepted: 01/11/2023] [Indexed: 01/13/2023]
Abstract
In the solvent extraction process, the importance of an extractant (or ligand) and a diluent is inferred from their respective physicochemical properties. We have brought together all the recent results reported on the mixture of different extractants dissolved in a well-known ionic liquid diluent: 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4 mim][NTf2 ]) in the form of a review and aimed to emphasize the role of ligand polarity and structure on the physicochemical properties of an ionic liquid (IL) diluent. Some of the most important properties such as dynamic viscosity (η), absolute density ( ρ ${{\rm{{\rm \rho} }}}$ ), energy of activation (Ea ), coefficient of thermal expansion (α), phase separation time (PST), refractive index (n), etc., have been discussed meticulously in the paper. The effect of ligand structure on the aggregation behaviour of IL phase and the physicochemical properties of gamma irradiated solvent phases containing different ligands and their solution with IL phase also have been deliberated in detail.
Collapse
Affiliation(s)
- Alok Rout
- Materials Chemistry & Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102, India
| | - Satyabrata Mishra
- Reprocessing Research & Development Division, Reprocessing Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 603102, India
| |
Collapse
|
3
|
Gujar RB, Verma PK, Mahanty B, Bhattacharyya A, Musharaf Ali S, J. M. Egberink R, Huskens J, Verboom W, Mohapatra PK. Sequestration of Np4+ and NpO22+ions by using diglycolamide-functionalized aza-crown ethers in C8mim·NTf2 ionic liquid: Extraction, spectroscopic, electrochemical and DFT studies. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
4
|
Verma PK, Mohapatra PK. Fate of Neptunium in nuclear fuel cycle streams: state-of-the art on separation strategies. RADIOCHIM ACTA 2022. [DOI: 10.1515/ract-2022-0008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Neptunium, with a half life of 2.14 million years is one of the most notorious activation products in the nuclear fuel cycle. It has been more than 5 decades in the reprocessing of nuclear fuels by the well documented PUREX process, but the fate of Np in the PUREX cycle is still not well controlled. Although Np being stable in its pentavalent state in low acid media, its starts to undergo disproportionation at higher acidities. This disproportionation along with the oxidizing conditions of the HNO3 medium makes Np to exits as Np(IV), Np(V) and Np(VI) in the dissolver solution. The overall extractability of Np in the co-decontamination step of the PUREX cycle is dependent on its oxidation state in the medium as Np(VI) and Np(IV) being extractable while Np(V) being least extractable. The present review article discusses about the speciation of Np in HNO3 and its disproportionation. The variety of redox reagents are discussed for their effectiveness towards controlling Np redox behavior in the HNO3 media. The extraction of Np with the different class of extractant has also been discussed and the results are compared for better understanding. Solid phase extraction of Np using both commercially available resin and lab based synthesized resins were discussed. The anion exchange resins with the different cationic centers were shown to behave differently towards the uptake of Np form the acidic medium. The present review also highlight the chemical conditions required for controlling or minimizing the fate of Np in different process streams of the nuclear fuel cycle.
Collapse
Affiliation(s)
- Parveen K. Verma
- Radiochemistry Division , Bhabha Atomic Research Centre , Trombay , Mumbai 400085 , India
| | - Prasanta K. Mohapatra
- Radiochemistry Division , Bhabha Atomic Research Centre , Trombay , Mumbai 400085 , India
| |
Collapse
|