Liquid-liquid equilibria of aqueous two-phase systems containing polyvinylpyrrolidone and tripotassium phosphate or dipotassium hydrogen phosphate: Experiment and correlation

Liquid-liquid equilibrium (LLE) data for aqueous polyvinylpyrrolidone (PVP) + tripotassium phosphate and aqueous (PVP) + dipotassium hydrogen phosphate systems have been obtained experimentally at T=(298.15,308.15 and 318.15)K. Furthermore, the Merchuk equation has been used to correlate the experimental binodal data for these systems; and the two-parameter equation and the extended NRTL model have been successfully used to correlate the tie-lines data of these systems. Finally, the effects of temperature and the type of salt on LLE are discussed.