Liquid-liquid equilibrium study of 1-Dodecyl-3-Methyl-Imidazolium Dicyanamide + Inorganic salt + Water systems

The phase behavior of a new ternary aqueous two-phase system (ATPS) based on [1-Dodecyl-3-Methyl-Imidazolium][Dicyanamide] ionic liquid and two inorganic salts of Na 2 CO 3 and Na 2 SO 4 were studied separately at two different salts concentrations and different temperatures (= 288.15, 298.15, and 308.15 K), all at atmospheric pressure (0.1 MPa). This surface-active ionic liquid was chosen due to its similar properties to cationic surfactants and its widespread use in separation processes. The chemical structure of the synthesized ionic liquid was investigated using Fourier Transform Infrared (FTIR), Nuclear Magnetic Resonance (NMR) and Diffuse Reflection (DRS) Spectroscopies, residual chlorine test, and melting point test. The experimental data correlated by the symmetrical local composition model of UNIQUAC-NRF with symmetric Pitzer − Debye − Hückel (PDH) theory. The results demonstrated a minor effect of temperature on the separation process, and the salt ability in phase separation was increased at higher concentrations. A pleasant agreement between correlated data and the experimental results was also found.