Thermophysical properties of phosphonium-based ionic liquids

Area of Science:

• Materials Science
• Physical Chemistry
• Chemical Engineering

Background:

• Ionic liquids (ILs) are tunable solvents with unique properties.
• Phosphonium-based ILs are of interest for various applications.
• Accurate physical property data is crucial for IL design and application.

Purpose of the Study:

• To experimentally determine density, viscosity, refractive index, and surface tension for four phosphonium-based ionic liquids.
• To estimate derivative properties including thermal expansion coefficients and critical temperatures.
• To evaluate the applicability of group contribution methods for predicting IL properties.

Main Methods:

• Experimental measurements of key physical properties at temperatures from 288.15 K to 353.15 K.
• Calculation of derived thermodynamic and physical properties.
• Application and fitting of group contribution methods to experimental data.

Main Results:

• Comprehensive datasets for density, viscosity, refractive index, and surface tension were obtained.
• Estimated derivative properties provide further insights into IL behavior.
• Group contribution methods showed varying degrees of success in predicting experimental data.

Conclusions:

• The study provides valuable experimental data for phosphonium-based ionic liquids.
• Group contribution methods require further refinement for accurate IL property prediction.
• The findings support the use of these ionic liquids in various chemical processes.