Evaluation of physical properties of ionic liquids

  • Nan Zhao

Student thesis: Doctoral ThesisDoctor of Philosophy


Firstly, experimental data for ionic liquids properties; density, viscosity of pure ionic liquids, viscosity of binary ionic liquid mixtures, and solubility in molecular solvents were collected from the literature and thus four databases were compiled. Then mathematical gnostics was used to analyse the uncertainty and discrepancy of experimental data reported from different resources and to recommend reliable datasets.The volumetric properties of ionic liquids were evaluated by using a group contribution method. The volumetric parameters of 55 ions were calculated by correlating 5,399 training data points using the Tait-type equations. 2,522 test datapoints were used to validate the accuracy of this method. This method also allows the calculation of mechanical coefficients with a good agreement.The viscosity of pure and binary mixtures of ionic liquids was estimated using a new method based on the UNIFAC-VISCO model. The dataset containing 819 experimental viscosity data points for 70 pure ionic liquids was correlated using the modified UNIFAC-VISCO method, thus the interaction parameters and ion VFT parameters were estimated, which were used for the evaluation of 11 types of binary mixtures. A good agreement with the evaluation of binary mixtures in turn proved that the parameters estimated were accurate enough to estimate the viscosity of pure and mixtures ionic liquids.The liquid-liquid-equilibrium data for binary mixtures; ionic liquid and a molecular solvent, were modelled using the UNIQUAC and UNIFAC methods. A user-friendly web based interface was established and all the mutual solubility data between the ionic liquid and molecular solvents were uploaded to the online database, which allows end user to get reference data in academy and industry.
Date of AwardMay 2017
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorJohan Jacquemin (Supervisor) & Volkan Degirmenci (Supervisor)

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