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In order to expand our understanding of a potential zinc-basedbattery electrolyte, we have characterized the physical and transportproperties of the ionic liquid (IL) 1-butyl-1-methylpyrrolidiniumdicyanamide ([C4mpyr][dca]) containing various levels ofboth Zn2+and H2O. Detailed measurements ofdensity, viscosity, conductivity, and individual anion and cationdiffusion coefficients using pulsed-field-gradient (PFG) NMR combinedwith NMR chemical shifts and spin–lattice relaxation (T1) NMR experiments provide insights into themotion and chemical environment of all molecular species. We findthat the various techniques for probing ion transport and dynamicsform a coherent picture as a function of electrolyte composition.Zn2+addition causes a moderate reduction in the self-diffusionof the IL anion and cation, whereas the addition of H2Oincreases ion mobility by increasing the liquid’s overall fluidity.Temperature-dependent 13C T1experiments of the dca carbon analyzed using Bloembergen–Purcell–Poundfits show monotonic slowing of anion dynamics with Zn2+addition, suggesting increased Zn2+/dca–association. T1experiments show minimalchange in the spin–lattice relaxation of cation or anion uponH2O addition, suggesting that H2O is playingno significant role in Zn2+speciation. Finally, we employa novel electrophoretic NMR technique to directly determine the electrophoreticmobility of the C4mpyr cation, which we discuss in thecontext of impedance-based conductivity measurements. [ABSTRACT FROM AUTHOR]

High methane dissolution capacity in a liquid is important for methane storage and transformation. In this work, methane solubility in different ionic liquids (ILs) was studied and was found associated with IL's structural and physical properties. In imidazolium-based ILs, ILs containing C-F and long alkyl chain showed high methane solubility mainly due to lower surface tension and molar density. Reducing the surface tension of solvent by adding 0.16 mol of trimethyl-1-propanaminium iodide (FC-134) with respect to [Bmim][NTf2] increased methane solubility by 39.3%. In situ high-pressure attenuated total reflection Fourier transform infrared spectroscopic results indicated a reversible process of methane dissolution in the ILs. The antisymmetric C-H stretching band of dissolved methane in ILs showed highly prominent rotational-vibrational bands with high intensity and narrow half-peak width compared to gaseous methane. Induced interaction between methane and IL resulted in increased dipole variation strength and reduced methane molecular symmetry. The constant antisymmetric C-H stretching peak at 3016.85 cm-1 revealed an unconstrained methane rotation in the stable physical and chemical environment of IL. Methane insertion into the IL's intranetwork space needs activation energy to overcome the interaction of cation-anion network. Kinetic analysis of methane in [Bmim][NTf2] and [Bmim][HSO4] at different temperatures indicated that methane dissolution in these two ILs was a reversible first-order and very weak endothermic process and that methane dissolution required high activation energy in ILs with stronger cation-anion interaction. [ABSTRACT FROM AUTHOR]

Ionic liquids have been widely studied as effective reaction media for the conversion of glucose or cellulose to 5-hydroxymethhylfurfural (5-HMF). However, the recovery of 5-HMF from ionic liquids, typically carried out by extraction, has been encountered with very low extraction efficiency, which limited the reusability of the solvents. Through this work, based on the model biphasic system that consists of 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) as the ionic liquid phase and methyl isobutyl ketone (MIBK) as the extractant phase, the dominant force that suppresses the extraction efficiency of 5-HMF was identified as being the strong hydrogen bonding between 5-HMF and [BMIM]Cl. Solvent mediation with functional promoters have been established as a new strategy to shift this force, resulting in improved extraction efficiency of 5-HMF from the ionic liquid. For example, with ethanol as a promoter, the distribution coefficient of 5-HMF was about 10 times higher than that without a promoter. [ABSTRACT FROM AUTHOR]