An effect of cation functionalization on thermophysical properties of ionic liquids and solubility of glucose in them – Measurements and PC-SAFT calculations

• Density, viscosity and DSC thermograms for four ionic liquids were measured.
• New data on solubility of glucose in ionic liquids were presented.
• An impact of cation functionalization on solubility was established.
• Apparent thermodynamic functions of dissolution were determined.
• Modeling of the studied systems with PC-SAFT equation of state was performed.

This contribution is concerned with thermodynamic investigation on thermophysical properties of four ionic liquids based on dicyanamide anion. The ionic liquids under study differ in substituent attached to imidazolium cation, so that an impact of terminal functional groups on the considered properties is established. Discussion is presented in terms of molecular packing and interactions (polarity, hydrogen bonding) between molecules forming system. Differential scanning calorimetry thermograms, density and viscosity were the investigated properties of pure ionic liquids. Moreover, new data sets on solubility of glucose in ionic liquids are presented. Analysis of the temperature-dependent solubility data by means of modified Van’t Hoff equation is given and apparent thermodynamic functions of dissolution are calculated. Thermodynamic modeling of the (solid + liquid) equilibrium phase diagrams was carried out by means of perturbed-chain statistical associating fluid theory (PC-SAFT). It is evidenced that consistent and accurate thermodynamic description of complex cross-associating {ionic liquid + sugar} systems can be achieved by using simple (but physically grounded) molecular schemes, assuming that two adjustable binary corrections are introduced.