Amine-facilitated up-hill transport of plutonium(IV) cations across an immobilized liquid membrane

Abstract

<span style="font-size:11.0pt;font-family:" calibri","sans-serif";="" mso-ascii-theme-font:minor-latin;mso-fareast-font-family:"times="" new="" roman";="" mso-hansi-theme-font:minor-latin;mso-bidi-font-family:arial;color:black;="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">The diffusion-limited and amine-facilitated plutonium (IV) ion permeation from nitric acid media across an immobilized liquid membrane (ILM) has been investigated to quantify the membrane carrier type effects on its transport. Amberlite LA-2 (Amb LA-2), Trilaurylamine (TLA) and Aliquat-336 (Ali- 336) have been tested as the carriers as typical examples of secondary, tertiary and quaternary amines, respectively. After suitable dilutions, the receptors have been immobilized on a microporous polymeric support and are held within the pores by capillary forces. Both the &nbsp;composition' of the organic membrane solvents and type of amine carrier have a marked effect on plutonium permeation. Recovery of Pu steadily increases from secondary to quaternary amines and its permeability across ILM follows the order: quaternary &gt; tertiary&gt; secondary. More than 95% pertraction of Pu(IV) is easily accomplished using tertiary or quaternary amine as ionophore across ILM in single run employing a feed solution containing about 5 mg/L Pu in 4 <i>M</i> nitric acid solution while the receiving phase was 0.1 <i>M </i>NH₂OH.HCI prepared in 0.3 <i>M</i> HNO₃ On the other hand, plutonium permeation is found to plummet to about 49% on employing secondary amine, Amb LA-2, as the carrier.</span>