Investigation on unusual role of N,N,N',N'-tetradodecyl diglycolamide in controlling the third phase formation in N,N,N',N'-tetraoctyl diglycolamide in n- dodecane during the trivalent metal ion extraction

N,N,N',N'-tetraoctyl diglycolamide (TODGA) in n-dodecane (n-DD) is one of the well established solvents for the separation of trivalent ions from nitric acid medium. Present study explores the usage of a higher chain homologue of TODGA, viz N,N,N',N'-tetradodecyldiglycolamide (TDdDGA) as the phase modifier. The extraction of nitric acid and trivalent metal ions by TODGA/n-DD upon addition of TDdDGA was studied and to understand the microscopic insights about the extraction behaviour, organic phase was subjected to dynamic light scattering measurements (DLS). The results thus obtained were compared with the corresponding unsymmetrical diglycolamide N',N' didodecyl N,N-tetraoctyl diglycolamide (D³DODGA) under similar conditions. Comparisons of the nitric acid extraction behaviour in four solvent systems were investigated and the results revealed that the addition of TDdDGA increased the nitric acid extraction limits in the combined system, without third phase formation even at 16 M nitric acid