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 twophase 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 fourthorder 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.

Measurement and Correlation of Phase Equilibria in Aqueous Two-Phase Systems Containing Polyoxyethylene Cetyl Ether and Three Organic Salts at Different Temperatures

“…The binodal data of polymer–salt ATPSs was correlated by the third-order polynomial equation (eq ), and the equation analogue effect was good. Equation was widely used to fit the binodal curves of many ATPSs. ,,,− In this work, the experimental binodal data of three ATPSs were regressed and analyzed by computer and the fitting parameters a , b , c , and d of three euqations were given in Tables – , where the square of correlation coefficients ( R 2 ) and the corresponding standard deviations (sd) were also shown. It was found that eq has a higher goodness-of-fit than the other two equations by comparison of the correlation coefficients and standard deviations given in three tables.…”

“…The corresponding tie-lines were shown in Figures – . As the widespread empirical correlation equations, the Othmer–Tobias and Bancroft equations (eqs and ) were used to correlate the tie-line compositions of many ATPSs. ,,,− , In investigated systems, the tie-lines data was fitted by using these two equations where w stands for the mass fraction of materials in ATPS, the subscripts “1”, “2”, and “3” respectively represent three substances of systems (POELE20, salt, and water), the superscripts “t” and “b” represent two phases of ATPS (the top phase and bottom phase), and k 1 , k 2 , n , and r were the fitting parameters whose values were shown in Table . The square of correlation coefficient values ( R 2 ) and standard deviations (sd) were shown in Table , and it was found that these two equations were qualified for the studied systems.…”

Environmentally Benign and Recyclable Aqueous Two-Phase System Composed of Distillable CO2-Based Alkyl Carbamate Ionic Liquids

“…The concentration of DIMCARB in phase solutions was measured spectrophotometrically using a UV–vis spectrophotometer at 350 nm. Then, the samples were subjected to vacuum drying using a freeze-dryer (CoolSafe series, ScanVac) at 181 K for 24 h . Both DIMCARB and water were vaporized after the drying, leaving the PPG as the residue.…”

Green, Aqueous Two-Phase Systems Based on Cholinium Aminoate Ionic Liquids with Tunable Hydrophobicity and Charge Density

“…The concentrations of IL in both phases were determined using an UV–vis spectrophotometer (Cary 100 UV–vis, Agilent Technologies) at 277 nm. To quantify the water content of the top and bottom phases, the samples were subjected to vacuum-drying at −92 °C for 24 h using a freeze-dryer (CoolSafe series, ScanVac) . The weight loss in the sample was equivalent to the mass of the water in the system.…”