Physicochemical Properties for the Binary Systems of Ionic Liquids [C_nmim]CI + N,N-Dimethylformamide

摘要

Density- p, refractive index n_D, and viscosity η for ionic liquids [C_nmim]Cl (C_nmim = 1-alkyl-3-methylimidazolium; n = 2, 4, 6, 8 for ethyl, butyl, hetyl, and octyl) + N,N-dimethylformamide (DMF) binary systems have been investigated at atmospheric pressure from 288.15 K to 318.15 K. The molar excess Gibbs energy △G~(*E), volumetric properties including excess molar volume V~E, and apparent molar volume V_(φ,j) have been calculated from the experimental data. Furthermore, the refractive index and viscosity deviations (△n_D; △η) from the ideal behavior have been obtained and well fitted to the Redlich—Kister equation. Our results show that DMF can effectively adjust the physicochemical properties of 1-alkyl-3-methylimidazolium ionic liquids.