Liquid–Liquid Equilibrium of Primary and Secondary Aqueous Two-Phase Systems Composed of Sucrose + Triton X-114 + Water at Different Temperatures

Abstract

Liquid–liquid equilibrium (LLE) data for aqueous two-phase systems (ATPSs) composed of sucrose, Triton X-114, and water were determined at 288 K, 293 K, and 298 K. At 293 K and 298 K, the top and bottom phases of the ATPS were enriched with sucrose and Triton X-114, respectively. However, phase inversion was observed in the ATPS formed at a lower temperature (288 K). When the temperature increased, the area of the biphasic region became larger, whereas the slopes and the lengths of the tie lines decreased. Binodal data obtained at different temperatures were correlated using a fourth-order polynomial equation, while tie-line data were correlated using the Othmer–Tobias and Bancroft equations. Moreover, the Setschenow equation was used to investigate the sugaring-out effect of sucrose on the formation of the ATPS. The correlated results and fitting parameters from these empirical equations confirmed the reliability and reproducibility of the experimental results. Furthermore, both top- and bottom-phase solutions can be heated to 303 K to form the secondary ATPSs composed of sucrose and Triton X-114, respectively. The LLE data for secondary ATPSs are presented in this paper.