离子液体[EOEMIM][NTf_(2)]与甲醇二元混合物的密度和粘度性质及半经验估算

DENSITIES AND VISCOSITIES PROPERTIES OF BINARY MIXTURES OF IONIC LIQUID 1-(2-ETHOXYETHYL)-3-METHYLIMIDAZOLIUM BIS[(TRIFLUOROMETHYL)SULFONYL]IMIDE[EOEMIM][NTf_(2)]WITH METHANOL AND ITS SEMI-EMPIRICAL ESTIMATION

为了更好的研究离子液体二元体系的性质,同时为了离子液体的应用研究提供理论数据,本研究测定了离子液体1-乙基乙基醚-3-甲基咪唑双(三氟甲烷磺酰)亚胺盐[EOEMIM][NTf_(2)]与甲醇二元混合体系(即摩尔分数x1=0.0000~1.000)在T=(288.15~318.15)K温度范围内间隔5 K的密度值和粘度值。二元混合物的密度和粘度值随着温度T的升高而减小,随着摩尔分数的增加而增大。二元混合物的平均摩尔体积随着温度的升高而减小,随着摩尔分数的增加而增大。热膨胀系数随着温度和摩尔分数的变化缓慢。二元混合物的超额摩尔体积均是负值,Redlich-Kister方程将超额摩尔体积对摩尔分数作图,在最低点时值最小,说明此时离子液体与甲醇分子间的相互作用力最强。粘度偏差和超额粘滞流动活化Gibbs自由能分别对摩尔分数进行R-K方程拟合,拟合效果良好。结合R-K方程参数值,提出估算二元混合物任何组成的平均摩尔体积半经验方法和粘度半经验方法,二元混合物的平均摩尔体积和粘度的估算值分别与他们相对应的实验值较好的一致。

In order to study the properties of the ionic liquid binary system and provide theoretical data for the application of ionic liquids research,viscosities and densities for[EOEMIM][NTf_(2)]with methanol binary mixtures had been measured across the entire range of molar fraction(x1=0.0000~1.0000)at T=(288.15~318.15)K interval 5 K.The values of density,viscosity and mean molar volume decrease with the increasing temperature and increase with the increasing mole fraction.Thermal expansion coefficient with the change of temperature and mole fraction is slow.The excess molar volumes are all negative over the entire composition range.Excess molar volumes of binary mixtures were fitted by Redlich-Kister equation.The interaction between ionic liquid and methanol is the strongest attractive interaction at the minimum point.Viscosity deviations and excess Gibbs free energy of activation for viscous flow for the binary mixture were both wellfitted by R-K equation.In terms of R-K parameters,the values of molar volume and viscosity for mixtures were estimated by semi-empirical method.The estimated values,V(est.)andη(est.),are in good agreement with the corresponding experimental ones,V(exp.).