| In this paper,hydrophobic ionic liquid 1-ethyl-3-（2-methoxyethyl）-imidazolium bis（trifluoromethylsulfonyl）imide,[C22O1IM][NTf2]was synthesized by using of N-ethylimidazole,2-bromoethyl methyl ether and bis（trifluoromethane）sulfonimide lithium salt.The product were characterized by 1H NMR spectroscopy,13C NMR spectroscopy,ESI-MASS spectra and Elemental Analyses（EA）.The spectrum analysis confirmed that the synthesized product was the target ionic liquids and the purity was more than 99%.Firstly,using thermogravimetric analysis,the vaporization enthalpy for ionic liquid[C22O1IM][NTf2]was determined,and the new scale of polarityδμbased on its vaporization enthalpy was obtained.Using the reported vaporization enthalpies and other physicochemical properties of the ionic liquid,the new scale of polarityδμfor other ionic liquids was calculated.According to the data,it is found that the values ofδμdecrease with increasing number of methylene（-CH2-）groups in the alkyl chains of the ILs.Theδμof some molecular solvents were also calculated,it can been seen that the polarity trends ofδμandεr for molecular solvents are consistent,that is,the new scale of polarityδμcould be used to obtain the polarity of molecular solvents.Then,the density and viscosity for binary mixtures of ionic liquid（IL）[C22O1IM][NTf2]with methanol and ethanol were measured across the entire range of mole fraction（x1=0.0000–1.0000）at T=（288.15–318.15）K.Based on the experimental values,the average molar volume（V）,the excess molar volume（VE）,the viscosity deviation,（Δη）and the excess Gibbs energy of activation for viscous flow(ΔG≠E)were calculated.The excess molar volumes（V E）and the excess Gibbs energy of activation for viscous flow(ΔG≠E)were well fitted by Redlich–Kister equation.Using the Redlich–Kister’s parameters,the values of average molar volume and viscosity for mixtures[C22O1IM][NTf2]with alcohols were estimated and the estimated V（est.）andη（est.）are in good agreement with the experimental ones,respectively. |
