Separation of Americium(III) and Europium(III) by thermal-swing extraction using thermosensitive polymer gel

Extraction separation of Am(III) and Eu(III) was examined by the thermal-swing extraction technique using a thermosensitive gel, poly-N-isopropylacrylamide (NIPA) crosslinked with a TPEN derivative, N,N,N′,N′-tetrakis(4-propenyl-oxy-2-pyridylmethyl)ethylenediamine (TPPEN). The separation of Am(III) from Eu(III) was observed in the swelling state of gel (5 °C) and the separation factor of Am(III) was evaluated as about 18 at pH 5.2. The distribution ratio of Am(III) was reduced to about 1/8 by the volume phase transition from the swelling state (5 °C) to the shrinking one (40 °C). These results suggest that Am(III) can be separated and recovered effectively from Eu(III) in nitrate aqueous solution by the thermal-swing extraction technique using TPPEN–NIPA gel. This technique is applicable to the MA partitioning process, which is one of the important chemical processes in the P&T technology.