EFFECT OF NITRIC ACID EXTRACTION ON PHASE BEHAVIOR, MICROSTRUCTURE AND INTERACTIONS BETWEEN PRIMARY AGGREGATES IN THE SYSTEM DIMETHYLDIBUTYLTETRADECYLMALONAMIDE (DMDBTDMA) / n-DODECANE / WATER: A PHASE ANALYSIS AND SMALL ANGLE X-RAY SCATTERING (SAXS) CHARACTERISATION STUDY

Effect of long-range interactions on ion equilibria in liquid–liquid extraction

“…equating activity to concentration is not adequate. Using selective actinide-lanthanide extraction performed in the DIAMEX process for trivalent lanthanide cations as a example [15], we show that considering only classical molecular complexation free energy as the dominant interaction can typically introduce a factor of 10 for the evaluation of the free energy driving extraction. Moreover, nonmonotonous behavior of selectivity is naturally obtained, not via a molecular property, but via an emerging property resulting from colloidal interactions occurring in the aggregates, all considered to be perfectly spherical, and not of fluctuating shapes taking into account non-zero temperature in the microstructure of the organic phase containing flexible fluctuating aggregates [16].…”

Influence of the extracted solute on the aggregation of malonamide extractant in organic phases: Consequences for phase stability

“…In 1992, NMR spectrometry was used to show that the malonamide molecule N,N 0 -dimethyl N,N 0 -dibutyl tetradecylmalonamide extractant (DMDBTDMA) contacted with water can be associated, and forms small aggregates (aggregation number about 4 to 6) [23]. A few years thereafter, Erlinger et al [17][18][19] studied the small angle scattering (neutron or X-rays) data of an organic solution of DMDBTDMA diluted in alkane contacted with nitric acid aqueous phase. This was quantitatively linked to a dispersion of spheres associated with a short-range ''sticky sphere'' attractive potential.…”

“…The concept of a colloidal approach enabled a better understanding of the organic solution of extractants [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. The first direct characterization of reverse micelles with interaction potential came from the modeling of small angle scattering intensities on absolute scale by Madic et al [17][18][19]. Over recent years, the TBP-alkane system has been reexamined [7][8][9][10][11][12][13], and TODGA organic phases have also been studied [14][15][16].…”

“…He indicated that the occurrence of phase splitting was due to the formation of reverse micelles, or microemulsion, in the organic diluent by the aggregation of TBP complexes. The concept of a colloidal approach enabled a better understanding of the organic solution of extractants [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. The first direct characterization of reverse micelles with interaction potential came from the modeling of small angle scattering intensities on absolute scale by Madic et al [17][18][19].…”

Small‐Angle Neutron Scattering Study of Plutonium Third Phase Formation in 30% TBP/HNO3/Alkane Diluent Systems

“…[11,12] Interpretation and analysis of the SANS scattering data has been largely based on the pioneering work on small-angle X-ray scattering measurements of the interactions between small reverse micelles in the N,N 0 -dimethyl-N,N 0 -dibutyl-2-tetradecylmalonamide (DMDBTDMA)-dodecane-HNO 3 solvent extraction system. [13,14] These works modeled the reverse micelle interaction via the Baxter model for hard-spheres with surface adhesion, also known as the "sticky spheres" model. [15] The Baxter model allows the calculation of the energy of interaction between small reverse micelles assumed as incompressible spheres.…”