Liquid-liquid equilibrium of (1H,1H,7H-perfluoroheptan-1-ol + perfluoroalkane) binary mixtures

This work presents new liquid-liquid equilibrium data for mixtures of 1H,1H,7H-perfluoroheptan-1-ol and linear perfluoroalkanes from C₆ to C₉. Data were measured at atmospheric pressure by turbidimetry and at pressures up to 5 MPa using a laser light scattering technique. The coexistence curves have been fitted to renormalization group extended-scaling expressions with the critical temperature and molar fraction obtained from the fit. The soft-SAFT equation of state (EoS) was also used to describe the experimental data at both low and high pressures. A good description of the immiscibility gap was obtained with this approach although results seem to deteriorate at high pressures showing that the model cannot simultaneously describe the equilibrium and excess thermodynamic properties.