Physicochemical and radiolytic degradation properties of dihexyloctanmide-imidazolium ionic liquid

•Physicochemical properties of DHOA/ionic liquid system for the first time•Radiolytic degradation studies of ionic liquid DHOA/ionic liquid system•Unusual interaction of DHOA with ionic liquid ([C4mim][NTf2])•FTIR investigation in DHOA/[C4mim][NTf2]•Aggregation of DHOA-ionic liquid-HNO3

N,N-dihexyloctanmide (DHOA) in ionic liquid medium has been proposed for the solvent extraction of actinides from nitric acid solutions. This paper reports the physicochemical and hydrodynamic properties of the solvent system containing N,N-dihexyloctanmide (DHOA) in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) ionic liquid, for the first time. The properties such as density, viscosity, phase disengagement time etc. were measured for irradiated and unirradiated liquids composed of DHOA, [C4mim][NTf2] and 1.1 M solution of DHOA in [C4mim][NTf2]. The results were compared with the values obtained for the nitric acid equilibrated-organic phases. ATR-FTIR spectroscopy and dynamic light scattering (DLS) measurement of the ionic liquid phase was employed for characterizing interaction between the ionic liquid-DHOA-nitric acid, and the aggregate size of the adduct formed in the solution.