Density and Speed of Sound of Binary Mixtures of Ionic Liquid 1-Ethyl-3-methylimidazolium Tetrafluoroborate,N,N-Dimethylformamide, andN,N-Dimethylacetamide at Temperature Range of 293.15–343.15 K: Measurement and PC-SAFT Modeling

Abstract

Density, ρ, and speed of sound, u, were measured for two binary mixtures, 1-ethyl-3-methylimidazolium tetrafluoroborate (1) + N,N-dimethylformamide (2) and 1-ethyl-3-methylimidazolium tetrafluoroborate (1) + N,N-dimethylacetamide (2), over the entire range of compositions at T = 293.15–343.15 K in 5 K intervals using an Anton Paar density and sound velocity analyzer (DSA 5000). Also excess molar volume, VmE, isentropic compressibility, ks, and isentropic compressibility deviation, Δks, were calculated. For these two binary mixtures, the VmE values were negative in x1 = 0.1–0.8, they were positive in x1 ≥ 0.8, and they became more negative with increase in the temperature from 293.15 to 343.15 K. For both systems, the most negative VmE values were observed in the region of x1 = 0.5. The VmE values were fitted to the Redlich–Kister polynomial equation. The perturbed chain statistical associating fluid theory (PC-SAFT) was also employed in order to correlate the densities of the binary mixtures at the temper...