2Nascimento K S(Ucon50-HB-2000+磷酸钾、柠檬酸钠).pdf

190 J. Chem. Eng. Data 2011, 56, 190–194 Liquid-Liquid Equilibrium Data for Aqueous Two-Phase Systems Composed of Ethylene Oxide Propylene Oxide Copolymers Kelany S. Nascimento,† Sonia Yelo,† Benildo S. Cavada,‡ Ana M. Azevedo,† and Maria R. Aires-Barros*,† Institute for Biotechnology and Bioengineering (IBB), Centre for Biological and Chemical Engineering, Instituto Superior Te´cnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal, and Biochemistry and Molecular Biology Department, Federal University of Ceara´ (UFC), CP 6033, CEP 60.451-970 Fortaleza, Ceara´, Brazil Phase equilibrium of aqueous two-phase systems (ATPS) containing UCON 50 HB-2000 + potassium phosphate and UCON 50 HB-2000 + sodium citrate were investigated in this work. The effect of temperature and type of salt were determined at (277.15, 298.15, and 313.15) K in pH 6.0, 7.0, and 8.0. Increasing the temperature of the phase system leads to an increase in the slope of the tie-line (STL) and in the tie-line length (TLL) causing a shift in the binodal position toward the origin. Sodium citrate showed a better capability to induce phase separation than potassium phosphate. Introduction strength.7 One common problem faced by ATPS is the difficulty in separating target biomolecules from the polymer solution. Phase separation in solutions containing polymer mixtures Since separation between the phase-forming polymers and is a very common phenomenon that was first reported in the 1 biomolecules after the primary extraction