Extraction separation of Am(III) and Eu(III) with thermosensitive gel introducing TPEN derivatives

Takeshita, Kenji*; Nakano, Yoshio*; Matsumura, Tatsuro  ; Mori, Atsunori*

A thermal-swing chromatographic process using a thermosensitive gel copolymerized with NIPA (N-isopropylacrylamide) and TPPEN (N,N,N',N'-tetrakis(4-propenyloxy-2-pyridylmethyl)ethylenediamine) was studied for the separation of Am(III) from Eu(III). Firstly, the radiolysis of the TPPEN-NIPA gel was tested by the -ray irradiation and the nuclide adsorption. The extraction separation of Am(III) was not influenced in the radioactive environment of the proposed process. Next, the TPPEN-NIPA gel was immobilized in porous silica particles and the applicability of the gel-immobilized silica to the proposed process was tested. Am(III) was extracted selectively in the gel-immobilized silica at 5C and the separation factor of Am(III) over Eu(III) was evaluated to be 3.7. The distribution ratio of Am(III) was reduced to less than 1/20 by increasing temperature from 5C to 40C. These results indicate that the TPPEN-NIPA gel is applicable to the thermal-swing chromatographic process for the MA recovery.