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

In the present work, physicochemical properties, such as density (ρ), refractive index ( n D ) and viscosity (η), for six binary systems containing [C n mim]Cl (C n mim = 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 (Δ n 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.