293.15K时咪唑醋酸盐-乙醇二元体系的体积性质及分子间相互作用简

用比重瓶法测定了293.15 K时1-甲基咪唑醋酸盐(Mim]Ac)/1，3-二甲基咪唑醋酸盐(Mmim]Ac)/1-乙基-3-甲基咪唑醋酸盐(Emim]Ac)-乙醇(EtOH)二元体系在全组成范围内的密度. 计算出Mim]Ac/Mmim]Ac/Emim]Ac和EtOH的表观摩尔体积和体系的超额摩尔体积. 用三参数多项式关联拟合了表观摩尔体积与摩尔分数的关系，外推出组分的极限偏摩尔体积和摩尔体积. Mim]Ac/Mmim]Ac/Emim]Ac和EtOH的摩尔体积的外推值与实验值分别在±0.07和±0.04 cm3/mol范围内相一致. 计算出了Mim]Ac/Mmim]Ac/Emim]Ac和EtOH分别在无限稀溶液中的溶剂化系数. 用Redlich-Kister 方程关联拟合了超额摩尔体积与摩尔分数的关系. 分别根据极限偏摩尔体积、摩尔体积与极限偏摩尔体积的差值、溶剂化系数和超额摩尔体积对照讨论了分子间相互作用的强弱. 结果显示，在Mim]Ac/Mmim]Ac/Emim]Ac的浓度无限稀溶液中，Mim]Ac/Mmim]Ac/Emim]Ac-EtOH分子对间相互作用的强弱顺序为Mim]Ac-EtOH>Mmim]Ac-EtOH >Emim]Ac-EtOH；在EtOH的浓度无限稀溶液中，以及体系中Mim]Ac/Mmim]Ac/Emim]Ac的摩尔分数在0.15～0.95间时，Mim]Ac/Mmim]Ac/Emim]Ac-EtOH分子对间相互作用的强弱顺序都为Emim]Ac-EtOH>Mmim]Ac-EtOH>Mim]Ac-EtOH.

Volumetric Properties and Molecular Interactions of Binary Mixtures Imidazolium Acetates-ethanol at 293.15 K

Over the full molar fraction range and at 293.15 K, the densities of binary systems 1-methylimi-dazolium acetate(Mim]Ac)/1,3-dimethylimidazolium acetate(Mmim]Ac)/1-ethyl-3-methylimidazolium acetate(Emim]Ac)(1)-ethanol(EtOH)(2) were measured by pycnometer method. The apparent molar volumes of Mim]Ac/Mmim]Ac/Emim]Ac and EtOH, and the excess molar volumes of the binary mixtures were calculated. The relations of apparent molar volumes and molar fractions were fitted by three-parameter polynomials, from which, the limiting partial molar volumes and molar volumes were extrapolated. For Mim]Ac/Mmim]Ac/Emim]Ac and EtOH, the values of molar volumes from extrapolation and measurement are consistent with each other within ±0.07 and ±0.04 cm3/mol, respectively. The solvation coefficients at infinite dilutions of Mim]Ac/Mmim]Ac/Emim]Ac and EtOH were calculated. The Redlich-Kister equation was used to fit the excess molar volumes and molar fractions. Finally, the solute-solvent pairs' molecular interactions were discussed in terms of the limiting partial molar volume, the difference of molar volume and limiting partial molar volume, the solvation coefficients at infinite dilutions, and the excess molar volume. The results show that the sequence of molecular interaction at infinite dilutions of Mim]Ac/Mmim]Ac/Emim]Ac is Mim]Ac-EtOH >Mmim]Ac-EtOH >Emim]Ac-EtOH, and that at infinite dilutions of EtOH and Mim]Ac/Mmim]Ac/Emim]Ac of x1=0.15—0.95, the sequence is Emim]Ac-EtOH >Mmim]Ac-EtOH >Mim]Ac-EtOH.