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Equilibrium data were determined for aqueous two-phasesystemscomposed of poly(ethylene glycol) (PEG), maltodextrin (MD), and water.The systems were prepared by varying the PEG molar mass (4000 g·mol–1, 6000 g·mol–1, and 8000 g·mol–1) and the dextrose equivalent (DE) of the MD (10.5and 15). The temperatures tested were 298.2 K, 308.2 K, and 318.2K. For the systems studied it was observed that the molar mass ofthe PEG did not sensitively affect the equilibrium curve position,and as the DE of MD increased, the concentration of polymers usedto form the phases decreased. In some systems temperature minimallyinfluenced the displacement of the equilibrium curve. [ABSTRACT FROM AUTHOR]

The effect of poly(ethylene glycol) (PEG) molar mass,pH, and temperatureon interfacial tension was investigated for aqueous two-phase systemscomposed of PEG with molar masses of (1500, 4000, 6000, and 8000)g·mol–1and potassium phosphate. The temperaturestested were (293 and 313) K at the pH values of 6, 7, and 9. Interfacialtension was determined by using a spinning drop tensiometer and theVonnegut equation. An increase in both the PEG molar mass and thetemperature resulted in an increase of interfacial tension values.The interfacial tension varied from (0.05 to 3.11) mN·m–1for systems composed by PEG 4000 (mass fraction; w= 0.12) potassium phosphate (w= 0.11) water(w= 0.77) at pH 6.0 and 293 K and PEG 4000 (w= 0.19) potassium phosphate (w= 0.16) water (w= 0.65) at pH 7.0 and 313 K, respectively. [ABSTRACT FROM AUTHOR]