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@INPROCEEDINGS{DiazGomez:909862,
      author       = {Diaz Gomez, Laura Johana and Wilden, Andreas and Modolo,
                      Giuseppe and Gullo, M. C. and Verboom, Willem},
      title        = {{S}olvent extraction studies of different diastereomers of
                      modified diglycolamide ligands for {A}n({III}) and
                      {L}n({III}) extraction},
      reportid     = {FZJ-2022-03475},
      year         = {2022},
      abstract     = {BackgroundSolvent extraction is currently the preferred
                      technique for the separation of actinides (An) from fission
                      products (FP), and especially lanthanides (Ln), as
                      constituents of Spent Nuclear Fuel (SNF) or PUREX raffinate.
                      For this purpose, the separation of minor actinides (MA),
                      especially Am(III) from Cm(III), Eu(III) and other Ln(III)
                      is the current challenge of interest. Nowadays, extractants
                      only made by carbon, hydrogen, oxygen, and nitrogen (CHON
                      principle) are preferred for the extraction of MA, because
                      they can be completely incinerated. Diglycolamides (DGA)
                      showed promising results as extractants for trivalent Ln and
                      An, such as N,N,N’,N’-tetra-n-octyl diglycolamide
                      (TODGA), which usually have a higher affinity for Cm(III)
                      over Am(III). Wilden et al. reported a variation of the
                      Am(III) selectivity over Cm(III) with differently orientated
                      methyl substitutions (syn and anti) in the ligand backbone
                      of Me2-TODGA (Wilden et al., 2019). Here, we study the
                      selectivity and affinity of derivative extractants of TODGA
                      and N,N,N’,N’-tetra-n-decyl diglycolamide (TDDGA) with
                      dipropyl and ethyl-methyl substitutions in the molecule
                      backbone, and their respective diastereomers.MethodsThe
                      experiments were carried out at different nitric acid
                      concentrations (0.8 – 9.8 mol L-1) containing all Ln(III)
                      (except Pm) and other fission products. 241Am, 244Cm, 152Eu
                      and 239Pu(IV) were added as radioactive tracers. The new
                      extractants were tested as 0.1 mol L-1 solution in
                      n-dodecane. The extraction was carried out at 22°C for 30
                      min. After centrifugation for 5 min., phases were separated
                      by hand using fine-tip pipets. Organic and aqueous phase
                      samples were measured using gamma and alpha spectrometry and
                      ICP-MS.ResultsThe steric hindrance from the alkyl side
                      chains gave generally low distribution ratios (D < 1.5) for
                      the trivalent metal ions. In comparison, Pu(IV) showed
                      remarkably higher distribution ratios at the same HNO3
                      concentrations (D > 10). The syn-ethyl-methyl substitutions
                      for both analogues showed the highest D values for Am(III)
                      and all metals (except Ru) by all of the tested ligands
                      giving promising molecules for further studies. No third
                      phase formation was observed for any of the ligands. The
                      results of the extraction studies will be presented and
                      discussed in the poster.ConclusionsAmong the tested ligands,
                      syn-ethyl-methyl substitution for both diglycolamides (octyl
                      and decyl side chains) gave the highest D values for all Ln
                      and An. Nevertheless, the D values were much lower than for
                      their unsubstituted parent molecules. Pu(IV) was extracted
                      much better rising the attention for extraction of
                      tetravalent ions. Further studies aim at increasing the D
                      values by e.g., increasing the ligand
                      concentration.ReferencesWilden, A., Kowalski, P. M., Klaß,
                      L., Kraus, B., Kreft, F., Modolo, G., . . . Verboom, W.
                      (2019). Unprecedented Inversion of Selectivity and
                      Extraordinary Difference in the Complexation of Trivalent
                      f-Elements by Diastereomers of a Methylated Diglycolamide.
                      Chem. Eur. J., 25(21), 5507-5513.
                      https://doi.org/10.1002/chem.201806161},
      month         = {Sep},
      date          = {2022-09-26},
      organization  = {International Solvent Extraction
                       Conference ISEC 2022, Gothenburg
                       (Sweden), 26 Sep 2022 - 1 Oct 2022},
      subtyp        = {Other},
      cin          = {IEK-6},
      cid          = {I:(DE-Juel1)IEK-6-20101013},
      pnm          = {1412 - Predisposal (POF4-141) / Verbundprojekt:
                      Untersuchungen zur SEParation von AMericium aus
                      hochradioaktiven Abfalllösungen (SEPAM), Teilprojekt A
                      (02E11921A)},
      pid          = {G:(DE-HGF)POF4-1412 / G:(BMWi)02E11921A},
      typ          = {PUB:(DE-HGF)24},
      url          = {https://juser.fz-juelich.de/record/909862},
}