Binary Vapor–Liquid and Vapor–Liquid–Liquid Equilibria of Hydrofluorocarbons (HFC-125 and HFC-143a) and Hydrofluoroethers (HFE-125 and HFE-143a) with Ionic Liquid [emim][Tf2N]

Solubility behaviors of binary HFC-125 (CF 3 −CF 2 H), HFE-125 (CF 3 −O−CF 2 H), HFC-143a (CF 3 −CH 3 ), and HFE-143a (CF 3 −O−CH 3 ) systems with room-temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([emim][Tf 2 N]) have been studied using a gravimetric microbalance method from (283 to 348) K and/or volumetric and cloud-point methods. Vapor–liquid equilibrium (VLE) data for HFC-125 + [emim][Tf 2 N] and HFE-125 + [emim][Tf 2 N] systems have been well correlated with our equation-of-state (EOS) model, which predicted vapor–liquid–liquid equilibria (VLLE) for both of these binary systems, and the VLLE have been experimentally proved. As for the binary systems of HFC-143a + [emim][Tf 2 N] and HFE-143a + [emim][Tf 2 N], only VLLE experiments have been made, and partial miscibility (temperature and composition: VLLE− Tx ) data are well correlated with the NRTL (nonrandom two-liquids) activity model. While the immiscibility gap of the HFC-125 binary system is smaller than that of the HFE-125 system, the immiscibility behaviors for the HFC-143a and HFE-143a systems are opposite; the HFE-143a system is more soluble.