Study of the Physicochemical and Excess Properties of Binary Systems Composed of Ionic Liquids ([C_nmim]Cl, n = 6, 8) and Three Dipolar Aprotic Solvents at T = 288.15–333.15 K

Abstract

In the present work, physicochemical properties, such as density (ρ), refractive index (n_D) and viscosity (η), for six binary systems containing [C_nmim]Cl (C_nmim = 1-alkyl-3-methylimidazolium; n = 6, 8) and three dipolar aprotic solvents [N-methyl-2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone)] were measured at wide composition ranges and temperatures from T = 288.15 to 333.15 K at atmosphere pressure. Moreover, the derived properties, such as excess molar volumes (), apparent molar volumes (V_φ,i), deviations in refractive index (Δn_D), and isobaric thermal expansivity coefficients (α_P), were calculated. The Redlich–Kister polynomial equation was fitted to the excess molar volumes and the deviation in refractive index data. The experimental results in this work allow us to discuss the interactions in the mixtures. The physicochemical properties of such systems may be useful for applications of imidazolium-based ionic liquids in the field of chemical engineering.

Keywords:

• Density
• Dipolar aprotic solvents
• Imidazolium-based ionic liquids
• Refractive index
• Viscosity

Supplemental Material

Supplemental data for this article can be accessed on the publisher's website website at http://dx.doi.org/10.1080/00986445.2015.1114477