Refractive Indices of Aqueous Blends of Ammonium-Based Ionic Liquids and Potassium Carbonate

Carbon dioxide (CO2) capture via chemical absorption to capture excess CO2 in a variety of gas streams has emerged as an important operation in industrial process. This project concerns the thermophysical properties study of aqueous blends of ammonium-based ionic liquids (AILs), a new class of unique solvents that has emerged as cheaper and greener alternatives due the possibility of tuning its properties by combining between cations, anions and/or possibly the introduction of functional groups. The specific AIL of particular interest in this study is tetrabutylammonium hydroxide (TBAOH), blended with the common solvent, potassium carbonate (K2CO3). Experimental data of refractive indices of aqueous blends of TBAOH and K2CO3 are measured in the temperature range between 303.15 and 333.15 K and at varying degrees of concentration. Based on the gathered results as well as comparative study with previous literature, the influence of varying temperature and concentrations on the refractive indices of these blends are discussed. Derived correlational properties such as polarizabilities, molar refractions and free volumes are also predicted by utilizing techniques from past studies.