The new experimental data and a new thermodynamic model based on group contribution for correlation liquid–liquid equilibria in aqueous two-phase systems of PEG and (K2HPO4 or Na2SO4)

摘要: The new experimental data of liquid–liquid equilibria for aqueous two-phase systems PEG–K2HPO4–water and PEG–Na2SO4–water are presented. effects pH molecular weight polyethylene glycol were investigated the tie lines with binodal curves both shown. A thermodynamic model based on group contribution has been proposed studying phase behavior polymer–salt systems. assumptions NRTL-NRF activity coefficient equation UNIQUAC-NRF have used groups. In this model, UNIFAC-NRF, nonrandom state groups selected as a reference state. binary interaction parameters adjusted using salt–water ternary correlated only six adjustable parameters. Debye–Huckel Fowller–Guggenheim was to calculate long range electrostatic ions. UNIFAC-NRF applied correlate systems: two different PEG at pH. results showed that it can be LLE in solution very well.