Density and Viscosity for Binary Mixtures of the Ionic Liquid 2,2-Diethyl-1,1,3,3-Tetramethylguanidinium Ethyl Sulfate with Water, Methanol, or Ethanol

Abstract

The ionic liquid (IL), 2,2-diethyl-1,1,3,3-tetramethylguanidinium ethyl sulfate ([(C2)22(C1)2(C1)23gu][C2OSO3]), was synthesized and characterized. The density and viscosity data were determined for the binary mixtures of [(C2)22(C1)2(C1)23gu][C2OSO3] with water, methanol, or ethanol over the whole concentration range at different temperatures T = 293.15–323.15 K and atmospheric pressure p = 0.1 MPa. The excess molar volume, VmE, and viscosity deviation, Δη, for the binary mixtures are calculated and fitted with the Redlich–Kister type polynomial equation. The values of VmE for [(C2)22(C1)2(C1)23gu][C2OSO3] + water system are observed to be negative, and those for [(C2)22(C1)2(C1)23gu][C2OSO3] + methanol/ethanol system change from negative to positive against the mole fraction (x1) of the IL, which exhibit the minimum values around x1 = 0.2 and the maximum values near x1 = 0.8. The Δη values for all of the three binary systems are negative, and the minimum values occur near x1 = 0.6. The temperature depen...