The effects of temperature and pH on the phase equilibrium of aqueous two phase systems containing polyvinylpyrrolidone and K2HPO4 / KH2PO4 buffer: Experimental and modeling

Liquid-liquid equilibrium (LLE) data of the aqueous polyvinylpyrrolidone (PVP) + K2HPO4 / KH2PO4 buffer system at various temperatures ( 298.15, 308.15 and 318.15 ) K and pH 5 and pH 7 were studied. It was found that, an increasing in temperature and pH caused the expansion of two-phase area. Furthermore the osmotic virial equation and Flory-Huggins- Debye-Huckel theory were used to correlate the phase behavior data of this system. Good agreement was obtained with the experimental data using these models.

کلیدواژه ها:

Liquid-liquid equilibrium ، K2HPO4 / KH2PO4 buffer ، Poly vinylpyrrolidone ، Osmotic virial equation ، Flory-Huggins- Debye-Huckel theory