(262ay) Physico-Chemical Characterization of Fluorinated Ionic Liquids for Their Use As Blood Substitutes

The fluorination of ionic liquids (ILs) (fully or partially) is of particular interest in areas where perfluorocarbons (PFCs) find relevant applications, such as separation methods and fluorous phase organic synthesis, surfactants in supercritical solvents, substitutes for chlorinated solvents or biomedical applications. In the latter case, PFCs are used as in vivo gas carriers in liquid ventilation or artificial blood substitute formulations [1]. This first generation of products, suitable as oxygen carriers only is now in clinical trials. It has an enormous potential in surgery with extensive blood loss, and different substitutes have already been developed for this purpose.

The nearly null volatility of ionic liquids at atmospheric conditions, their easy recovery and therefore, recyclability, as well as their tunable toxicity completely justify the application of fluorinated ionic liquids (FIL) for improving the available oxygen therapeutics. The aforementioned aspects motivate the development of novel neoteric FILs combining the best of perfluorocarbons properties with those of ILs. However, it is crucial to consider multiple aspects related to their thermophysical behavior in the presence of water and respiratory gases.

In this contribution, the phase, interface and structural behaviour of some of these compounds have been theoretically characterized using the soft-SAFT molecular-based equation of state [2], in combination with the Density Gradient Theory (DGT) [3] for the study of interfacial properties. Based on new density, surface tension and phase equilibrium data [4], several FILs with the imidazolium and pyridinium cations, and the perfluoroalkylsulfonate [C₄F₉SO₃] perfluoroalkylcarbonate [C₄F₉CO₂] anions have been studied in detail. A molecular model based on the analysis of the distribution charges on the anion has been proposed and optimized to find a reliable set of parameter values describing the main properties of those fluids in good agreement with the data. An analysis of the molecular parameters based on the analogy between the chemical structures has been performed. Next, the vapor-liquid and liquid-liquid equilibria the respiratory gases (oxygen, nitrogen and carbon dioxide) and water has been reproduced. Preliminary results on the formation of aggregates are also provided. When data were not available, the theoretical approach was used to predict the solubility behaviour of the respiratory gases by transferring the molecular parameters.

Acknowledgements:

F. Llovell and Ana B. Pereiro acknowledge two Short Term Scientific Mission Grants (STSM-CM1206-020315-056728 and STSM-CM1206-010316-071781 STSM), within the framework of the COST Action EXIL - Exchange on Ionic Liquids. Additional support was provided by a TransBio SUDOE collaborative project (TRANSBIO-BCN-GT2-A1-03), the Catalan Government (2014SGR-1582) and the Fundação para a Ciência e Tecnologia (FCT/MEC, Portugal) through the contracts under Investigador FCT 2014 (A. B. Pereiro and J. M. M. Araújo) and through the project PTDC/EQU-FTT/118800/2010.

References:

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