Investigation of the Effect of Temperature on the Physicochemical Properties of NMP-PA Ionic Liquid

Ionic liquids (ILs), on which much research has been done over the past two decades, have the potential to be used in organic reactions, Li-ion batteries, metal electroplating, extraction and separation processes, gas chromatography columns, carbon capture, desulfurization, and pharmaceutical industries. However, it is important to know ILs' physicochemical properties in order to evaluate the effects of them on the process and their use in the above-mentioned areas. N-Methyl pyrrolidone (NMP) and o-phosphoric acid (PA) have antimicrobial properties. NMP-PA IL synthesized from these two compounds may also have synergistic antimicrobial properties. In this study, FTIR, 1H NMR, 31P NMR, and DSC analysis were performed for the characterization of the synthesized NMP-PA IL. In addition, the density, refractive index, and dynamic viscosity of the synthesized IL were determined at different temperatures. The experimental data were correlated to empirical models. From the measurement results, it was found that the NMP-PA IL has a viscosity higher than that of the imidazolium-based ILs. Density and refractive index values of the IL were shown to be comparable to those of imidazolium-based ILs.