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Fugate, G.*; Takeshita, Kenji*; Matsumura, Tatsuro
Separation Science and Technology, 43(9&10), p.2619 - 2629, 2008/07
The compound N,N,N',N'-tetrakis(methylpyridyl)-1,2-ethylenediamine (TPEN) has been shown previously to exhibit a high separation factor for the separation of americium(III) and europium(III) but the application of this material to the nuclear fuel cycle is limited because of pH range of the separation (pH3 to 6) and the high solubility of the compound in acidic aqueous media. A variety of compounds have been synthesized during the course of this study in an attempt to retain the separation factor found in the parent compound while decreasing the working pH and aqueous solubility of the extractant. A series of compounds was synthesized in which the ethylene linker was replaced by several aromatic compounds. Another series of analogs was synthesized replacing two or more of the methylpyridyl groups with several different functional moieties. The separation properties of these new compounds were characterized and will be presented.
Takeshita, Kenji*; Fugate, G.*; Matsumura, Tatsuro; Nakano, Yoshio*; Mori, Atsunori*; Fukuoka, Sachio*
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM), p.120 - 125, 2007/09
Extraction separation of Am(III) and Eu(III) was examined by the thermal-swing extraction technique using a thermosensitive gel, poly-
-isopropylacrylamide (NIPA) copolymerized with a TPEN derivative, 
-tetrakis(4-propenyloxy-2-pyridylmethyl)ethylenediamine (TPPEN). The separation of Am(III) from Eu(III) was observed in the swollen state of gel (5
C) and the separation factor of Am(III) was evaluated as about 18 at pH5.2. More than 90% of Am(III) extracted into the gel was released by the volume phase transition of gel from the swollen state (5C) to the shrunken one (40C). The repetition test for the thermal swing extraction of a soft metal ion, Cd(II), which was used as a substitute of Am(III), was carried out and the extraction and release of Cd(II) were repeated three times stably under the thermal-swing operation between 5C and 40C. The radiation effect of gel on the extraction of Am and Eu was tested by the irradiation of 
-ray (10 kGy) and the long-term adsorption of 
-emitter (
Cm). The TPPEN-NIPA gel sustained no damage by these radiation tests. These results suggest that the thermal-swing extraction technique is applicable to the MA partitioning process indispensable for the establishment of P&T technology.