An investigation of the radiochemical stability of ionic liquids

Ionic liquids have been considered for their potential applications within the nuclear fuel cycle. If ionic liquids are to be successful in their application as solvents for highly radioactive materials in any future process, there will be a requirement for them to be robust to high radiation doses. A preliminary assessment of the radiation stability of 1,3-dialkylimidazolium cation based ionic liquids containing nitrate and chloride anions has been performed. The results of radiolysis studies are reported, in which the samples were exposed to alpha radiation from a tandem Van der Graaff generator, beta radiation from a linear accelerator and gamma radiation from cobalt 60 sources. These results suggest that their stability is similar to that of benzene and that they are much more stable than mixtures of tributylphosphate and odourless kerosene under similar irradiation conditions. The radiolysis of 1,3-dialkylimidazolium cation based ionic liquids reflects their combination of the properties of a salt, an alkane and an aromatic. They appear to be relatively radiation resistant and there is certainly no major decomposition of the organic component.