Reflectivity on liquid/liquid active interface using monoamide extractants

Proposal SC5637 revealed, via advanced liquid/liquid X-ray reflectivity, the unique uranyl distribution at the 3M nitric acid/dodecane-DEHiBA interface (extreme conditions). Novel methods to track reflected beam and cope with large concentration-gradients in liquid phases allowed us to get unprecedented insights with an uranyl enrichment in a interfacial diffuse nanometric layer, a structural feature that could be explained by the preorganisation of extractant/uranyl complexes within the interface. This continuation proposal has three goals: (i) extend measurements to lower and higher uranyl/extractant ratios to get further insight into transfer mechanisms, (ii) investigate back-stripping of uranyl into a less acidic aqueous phase, and (iii) probe long-term equilibria and interfacial structures, in comparison with neutron reflectivity data. A newly designed low-volume cell will improve safety, reduce costs, and enable future studies of synergistic solvent–extractant formulations.