New insights into the extraction of uranium(VI) by an N,N-dialkylamide

Abstract

International audienc

Determination of the Structures of Uranyl–Tri‐n‐butyl‐Phosphate Aggregates by Coupling Experimental Results with Molecular Dynamic Simulations

“…The calculated SWAXS intensity profiles are in good agreement with the experimental ones thanks to the use of a polarizable force field, as emphasized in our previous studies . The first I ( q ) peak is well reproduced at 14 nm −1 ; this corresponds to the first‐shell interactions of the aliphatic chains in solution.…”

“…This technique, based on “soft” ionization, transfers preexisting ions from solution to the gas phase and provides speciation information on species in solution. It has been applied to the characterization of the organic phase of extractant systems and gives relevant information ,. Solutions of TBP10 % and TBP30 % in contact with an aqueous solution containing uranyl nitrate were analyzed.…”

“…The trajectories were then analyzed by computing RDFs to determine the aggregation cutoff distances and corresponding aggregate populations were counted by using the CPPTRAJ AmberTools module . These sets of parameters have already provided results in good agreement with experimental data …”

“…The corresponding molar fractions have been used to build the starting MD simulation boxes. Another difference is the use of an all‐atom polarizable force field, which, to date, has only been used in three published studies for UO 2 2+ . As stated by Kunz et al., dispersion forces and polarization interactions are crucial to take into account for specific ion effects, especially for ions located in reverse micelle‐like aggregates, and therefore, are essential to represent proper structures resulting from 1) strong interactions of the extractant with the charged UO 2 2+ cation, and 2) weak extractant/diluent aliphatic chain interactions.…”

Depletion of water-in-oil aggregates from poor solvents: Transition from weak aggregates towards reverse micelles

“…The value of the area per molecule immediately gives the area per surfactant molecule present [9] and the amount of monomers coexisting in dynamic equilibrium is experimentally difficult to determine and is roughly in the order of 10 −3 M for all cases described up to now [10]. -"No" because there are recent experimental reports by Rodrigues [11] and Ferru [12] about well determined w/o aggregates, with four to height molecules per aggregate, that do not show a measurable Porod limit decay in scattering. These aggregates are in dynamic equilibrium with monomers of extractant dispersed in the solvent.…”