Separation Science and Technology, Vol.52, No.17, 2767-2776, 2017
Highly efficient extraction of tetra- and hexavalent plutonium using DGA functionalized pillar[5]arene in RTIL: Understanding speciation, thermodynamics and radiolytic stability
DGA functionalized pillar[5] arene (P5DGA) in ionic liquid was demonstrated as highly efficient system for the extraction of plutonium from acidic aqueous solution in tetravalent and hexavalent oxidation state. The extraction followed 'cation-exchange' mechanism via [Pu.P5DGA](4+) and [PuO2. P5DGA](2+), as extracted species for Pu4+ and PuO22+, respectively. Evaluation of thermodynamic parameters (Delta G, Delta H and.S) showed the feasibility and spontaneity of the extraction process. The process was exothermic and primarily 'enthalpy driven', since entropy change was found negative. P5DGA-RTIL solvent system showed good radiolytic stability even at 1000 kGy of gamma dose.