Density and viscosity of aqueous mixtures of N-methyldiethanolamines (MDEA), piperazine (PZ) and ionic liquids

The density and viscosity measurements of aqueous mixtures of N-methyldiethanolamine (MDEA), piperazine (PZ) and the ionic liquids (ILs) 1-n-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), 1-butyl-3-methylimidazolium dicyanamide ([bmim][DCA]), and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][OTf]) were conducted in this work. It was found that an increase in IL concentration resulted in an increase in the densities and viscosities of the aqueous mixtures. The density and viscosity equations for MDEA, PZ and IL aqueous mixtures as a function of temperature and concentration of ILs were derived as well. The density and viscosity equations obtained adequate accuracies with less than 0.34% and 4.013% of deviation from experimental data respectively.