Density and isothermal compressibility for two trialkylimidazolium-based ionic liquids at temperatures from (278 to 398)Â K and up to 120Â MPa

- Densities of two ILs were measured from T = (278.15 to 398.15) K and up to 120 MPa.
- Experimental densities were correlated to a Tammann Tait equation with a standard deviation lower than 2.8 · 10−4 g · cm−3.
- Gardas-Coutinho method predicts ρ with an AAD of 0.5% and 1% for [C4C1C1Im][(C2F5)3PF3] and [C4C1C1Im][NTf2], respectively.
- αp isotherms present an intersection point at moderate pressures for both ILs.
- The addition of a methylene group in the cation decreases the density.