γ-ray induced radiolysis of [C 2 mim][NTf 2 ] and its effects on Dy 3+ extraction

The water-soluble radiolytic products of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ionic liquid ([C2mim][NTf2]) under γ-radiation, such as CF3SOOH, CF3SO2NH2, HF, and H2SO3, were identified by using 1H NMR, 19F NMR, and ion chromatography. The extraction behavior of Dy3+ using irradiated [C2mim][NTf2] in combination with 2,6-di(5,6-diisobutyl-1,2,4-triazin-3-yl)pyridine (isobutyl-BTP) was studied and the abnormal increase of Dy3+ partitioning after irradiation is mainly attributed to the precipitation formed between Dy3+ and radiolytic products of [C2mim][NTf2] (F- and SO32-). Washing irradiated [C2mim][NTf2] with water provides a simple method for ionic liquid recycling.