Aqueous two-phase systems of poly(vinylpyrrolidone) and potassium citrate at different temperatures—Experimental results and modeling of liquid–liquid equilibrium data

The phase diagrams and compositions of coexisting phases have been determined for aqueous two-phase systems containing poly(vinylpyrrolidone) (PVP) and potassium citrate at various temperatures of 298.15, 308.15 and 318.15 K. The effect of temperature on the salting-out effect of poly(vinylpyrrolidone) by potassium citrate has been studied. The results have been discussed on the basis of the effect of temperature on the hydrophobicity of the polymer. Furthermore, the Wilson model has been used for the correlation of the experimental liquid–liquid equilibrium data. The agreement between the correlation and the experimental data is good.