High pressure densities of two nanostructured liquids based on the bis(trifluoromethylsulfonyl)imide anion from (278 to 398) K and up to 120 MPa

In this article the volumetric behaviour of the nanostructured liquids, butyltrimethylammonium bis(trifluoromethylsulfonyl)imide and 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, is reported. Density was measured in the temperature range (278.15-398.15) K up to 120 MPa with a high pressure densimeter based on the vibrating tube principle. Experimental densities were correlated as a function of temperature and pressure by means of the Tammann-Tait equation obtaining standard deviations lower than 3.5 × 10−4 g·cm−3. In addition, the isobaric thermal expansivity and the isothermal compressibility have been calculated from the Tait-like correlation. Furthermore, two group contribution methods proposed by Gardas and Coutinho and by Jacquemin et al. were applied to these fluids to analyse their prediction abilities for the high-pressure density.