Anion Effects on the Liquid-Liquid Equilibrium Behavior of Pluronic L64 + Water + Sodium Salts at Different pH: Determination of Thermodynamic Parameters

Two-phase aqueous systems have replaced and simplified steps in extraction purification processes, especially for biocompounds. Thus, this study evaluated the liquid-liquid equilibrium behavior of Pluronic L64 + water sodium salts at pH 5.0, 7.5, 10.0. Sodium sulfate demonstrated greatest phase separation, followed by citrate tartrate. Higher values resulted larger biphasic regions. The polymer distribution coefficients increased with addition salt. As increased, there was a tendency to migrate polymer-rich phase. Gibbs energy micellization between −11,000 −25,000 kJ mol−1 indicated spontaneity process all systems, showing lower sulfate. This parameter related anion speciation each pH. Besides, effects structuring around ions ion-polymer interaction influenced separation.