Volumetric behavior of two pyridinium-based ionic liquids

In this work the volumetric behavior in a broad range of temperatures (283.15 K–333.15 K) and pressures (0.1 MPa–65 MPa) of two pyridinium-based ionic liquids, namely: 1-ethyl-2-methylpyridinium bis(trifluoromethylsulfonyl)imide and 1-propyl-2-methylpyridinium bis(trifluoromethylsulfonyl)imide, is presented. The density–pressure–temperature data have been correlated successfully with two empirical equations: Tait and TRIDEN equations. Using these equations, relevant derived properties such as isobaric expansibility and isothermal compressibility have been obtained. Finally, the Paduszynski–Domanska group contribution method has been used to predict the volumetric behavior of our ionic liquids; a reasonable agreement between experiment and predicted data is found.