Influence of Extracted Solute on the Organization of a Monoamide Organic Solution

The amounts of extracted water, nitric acid and uranyl nitrate by organic phases of 0.5 mol.L-1 N,N-di–(ethylhexyl)isobutyramide (DEHiBA) in heptane have been measured experimentally. With the aim of investigating the influence of the solutes on the aggregation in these organic phases, Vapor Pressure Osmometry (VPO) and Small Angle X–rays Scattering (SAXS) measurements were carried out. The extraction of the different solutes promotes the aggregation in the order water < nitric acid < uranyl nitrate. Water extraction according to water activity seems to indicate the absence of chemical association between water and DEHiBA. The presence of nitric acid leads to the formation of small aggregates while uranyl extraction increases the organization of the organic solutions. This study is the first step to understand and quantify aggregation phenomenon in monoamide organic phases after solute extraction, which could explain the particular physical chemical behavior of such systems.