Polymer Inclusion Membrane Containing a Tripodal Diglycolamide Ligand: Actinide Ion Uptake and Transport Studies

A cellulose triacetate (CTA)-based polymer inclusion membrane (PIM) containing a C-pivot tripodal diglycolamide (T-DGA) as the carrier extractant and 2-nitrophenyl octyl ether (NPOE) as the plasticizer shows potential for the uptake of actinides from acidic feed solutions. The uptake of actinides (Am³⁺, Pu⁴⁺, Th⁴⁺, UO₂²⁺) was studied at 1 M HNO₃ with PIMs containing 25.6% T-DGA, 53.9% NPOE, and 20.5% CTA. The metal ion uptake followed the trend: Pu⁴⁺ > Am³⁺ > Th⁴⁺ > UO₂²⁺, which was in synch with the trend reported previously with PIMs containing <i>N</i>,<i>N</i>,<i>N</i>′,<i>N</i>′-tetrakis­(2-ethylhexyl) diglycolamide (T2EHDGA) as the carrier. The sorbed actinide ion could be desorbed from the PIMs using a solution of α-hydroxy-<i>iso</i>-butyric acid (AHIBA). Transport studies carried out with 1 M HNO₃ as the feed and 1 M AHIBA (at pH 3.0) as the receiver phase showed the trend: Am³⁺ > Pu⁴⁺ > Th⁴⁺ > UO₂²⁺, which was different than that observed from the uptake studies. Membrane stability was found to be reasonably good