Viscosity of [c4mim][(cf3so2)2n], [c4mim][n(cn)2], [c2mim][c2h5so4] and [aliquat][n(cn)2] in a Wide Temperature Range. Measurement, Correlation, and Interpretation

The viscosity of four in-house-made ionic liquids, 1-butyl-3-methyl-imidazolium bis(trifluoromethane sulfonylimide), ([C(4)mim][(CF3SO2)(2)N]), CAS RN 174899-83-3, 1-butyl-3-methyl-imidazolium dicyanamide, ([C(4)mim][N(CN)(2)]), CAS RN 448245-52-1, 1-ethyl-3-methyl-imidazolium ethylsulphate, ([C(2)mim][C2H5SO4]), CAS RN 342573-75- 5 and methyltrialkyl(C-8,C-8,C-10)ammonium dicyanamide [Aliquat][N(CN)(2)], CAS RN 63393-96-4, was measured in the temperature range 283.15 K = 373.15 K, at P = 0.1 MPa. Data obtained with an absolute relative uncertainty of U-r (eta) = 0.02 was compared with available literature data for all ionic liquids, except for [Aliquat][N(CN)(2)], data herein presented for the first time. Both the Vogel-Tammann-Fulcher and IUPAC/IAPWS equations were applied to correlate the measured viscosity data as a function of temperature, the latter being more accurate. Values of eta (298.15 K) are recommended for each ionic liquid studied. The viscosities of the different ionic liquids are discussed, considering their chemical structure differences. (C) 2021 Elsevier B.V. All rights reserved.