High pressure speed of sound and related properties of 1‑ethyl‑3‑methylimidazolium methanesulfonate

Abstract

Abstract The speed of sound in 1‑ethyl‑3‑methylimidazolium methanesulfonate was measured at pressures up to 61\u202fMPa in the temperature range from 293.15 to 323.15\u202fK. The density and isobaric heat capacity were conducted under atmospheric pressure at temperatures from 283.15 to 363.15\u202fK and 293.15 to 323.15\u202fK, respectively. The high pressure density, isobaric and isochoric heat capacities, isentropic and isothermal compressibilities, isobaric thermal expansion, and internal pressure were determined by means of the acoustic method. The data determined in this work by the acoustic method were compared with the data obtained by means of a high-pressure vibrating tube densimetry reported in [J. Mol. Liq. 238 (2017) 347–358]. Both investigations were carried out using the same batch of the 1‑ethyl‑3‑methylimidazolium methanesulfonate what eliminates the influence of impurities. Generally, a good agreement between two methods of thermophysical characterization of compressed liquids can be observed, however, some specific differences in relation to various determined properties are visible.