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Tri-n-butylphosphate (TBP) in an ionic liquid (IL) has been proposed as a suitable alternative for the solvent extraction of actinides from nitric acid solutions. This paper reports the detailed investigations on the physicochemical and hydrodynamic properties of the solvent system containing TBP in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide ([C4mim][NTf2]) IL. The properties such as density, viscosity, phase separation time (PST), etc., were measured for irradiated and unirradiated solvent phases composed of TBP, [C4mim][NTf2] and 1.1 mol.L-1 TBP in [C4mim][NTf2]. The results are compared with the values obtained in acid-equilibrated IL phases. ATR- FTIR spectroscopy and dynamic light scattering measurement of the IL phase were employed to characterize the interactions among the IL, TBP and nitric acid medium, and the aggregate size of the adduct formed in the IL phase. [ABSTRACT FROM AUTHOR]

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 ([C 4 mim][NTf 2 ]) 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, [C 4 mim][NTf 2 ] and 1.1 M solution of DHOA in [C 4 mim][NTf 2 ]. 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. [ABSTRACT FROM AUTHOR]

The major objective of this paper is the application of a reliable model to describe volumetric properties of imidazolium-based ionic liquids. In this regard, we have applied the Song and Mason equation of state for [Bmim][PF 6 ], [C 2 mim][NtF 2 ], [C 3 mim][NtF 2 ], [C 6 mim][NtF 2 ], [C 7 mim][NtF 2 ], [C 2 mim][EtOSO 3 ], [Bmim][MeSO 4 ], [Bmim][OcSO 4 ], [C 4 mim][dca], [Bmim][BF 4 ], [hmim][PF 6 ], [omim][PF 6 ] and [omim][BF 4 ]. This equation of state consists of three temperature dependent parameters. These parameters have been calculated as functions of reduced temperature with the use of a law of corresponding states. It is shown that knowledge of liquid density at the normal boiling point and normal boiling temperature are sufficient to predict the volumetric properties of these ionic liquids. We have taken 2469 experimental points for 13 ionic liquid to show the reliability of the present equation of state. The overall average absolute deviation is 1.06%. A comparison of the predicted results, using the present equation of state (which needs just two input parameters) with the results of some previous equations of state (needing 3 input parameters) indicates that this equation of state is more accurate than those. [ABSTRACT FROM AUTHOR]

In this paper, a densimeter based on vibrating tube principle is used to determine experimentally the density of 1-butyl-2,3-dimethylimidazolium tris(pentafluoroethyl)trifluorophosphate and 1-butyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide at temperatures between (278.15 and 398.15) K and at pressures up to 120 MPa. The apparatus was calibrated by using water, vacuum and bromobenzene. The Tammann–Tait equation of state was used to correlate ( p , T , ρ ) results with standard deviations around 2 · 10 −4 g · cm −3 . Other volumetric properties, such as isothermal compressibility and isobaric thermal expansivity, were obtained from this equation. For each ionic liquid, the α p isotherms present a crossing point within the experimental pressure range. Besides, the effect that the C2-methylation in the imidazolium cation provokes on density values is analyzed. The prediction ability of the group contribution methods of Gardas and Coutinho and Jacquemin et al. were tested with the experimental densities. [ABSTRACT FROM AUTHOR]

Abstract: Ether-functionalized imidazolium-based ionic liquids (EFIILs) exhibit extremely high SO2 solubility. In this paper, a series of EFIILs were prepared, and their structures were confirmed by 1H NMR. The thermodynamic properties of EFIILs, such as density, viscosity and surface tension, were measured from (298.15 to 343.15) K at atmospheric pressure. The molecular volume, coefficient of thermal expansion, standard entropy, surface entropy, and surface enthalpy were calculated from the experimental data. The results indicate that density, viscosity and surface tension of the specific EFIILs show linear decline as temperature rises, and decrease with the increase of ether chain length of the cation at the same temperature. The surface properties of EFIILs were also discussed systematically. [Copyright &y& Elsevier]