Liquid−Liquid and Liquid−Liquid−Solid Equilibrium in PEG + Cs₂SO₄ + H₂O

Abstract

The phase diagram was determined for the PEG + Cs2SO4 + H2O system at 25 °C using PEG (poly(ethylene glycol)) with a molecular weight of 4000. Compositions of the liquid−liquid and the liquid−liquid−solid equilibrium were determined using calibration curves for the index of refraction of the solutions; atomic absorption (AA) and TG analyses were made on the solids. The solid phase in equilibrium with the biphasic region was Cs2SO4. The binodal curves were correlated using a four-parameter equation. Tie lines were satisfactorily described using the Othmer−Tobias and Bancroft equations. The effects of temperature (25 °C, 35 °C and 45 °C) and molecular weight of the PEG (1000, 4000, and 10 000) on the binadol curve were also investigated. It was observed that the effect of the temperature was insignificant within the investigated range and an increase in the molecular weight of the PEG produced a displacement of the binodal curve toward the origin.

Solubilities, densities and refractive indices for the ternary systems ethylene glycol+MCl+H2O (M=Na, K, Rb, Cs) at (15 and 35)°C

“…In previous work, our research groups have focused on the solubility of rare alkali metal (Rb and Cs) salts in water + organic solvent [14][15][16][17]. The organic solvents including methanol, ethanol, 1-propanol, 2-propanol, as well as PEG [poly-(ethylene glycol)].…”

Cloud-point measurement for (sulphate salts+polyethylene glycol 15000+water) systems by the particle counting method

“…Therefore, the formation of the ATPS indicates the mutual exclusion of the salt and polymer and their high affinity for water. This trend is observed in all systems with PEG and inorganic salts [20,21]. da Silva and Loh [22] proposed a model based on calorimetric measurements that accounted for the trend in separation in terms of electrolyte and polymer efficacy interaction.…”

Activity Coefficients of CsCl in PEG 200–H2O and PEG 600–H2O Mixtures at 298.15 K

“…When evaluating the free energy interaction parameters, the standard transfer Gibbs energy ΔG t 0 m(M) (mol per kilogram of the mixed solvent) and ΔG t 0 m(W) (mol per kilogram of pure water) can be converted to each other as follows: 11 12) where m N is the molality of the PEG 200/600 (in mol/kg water) and M N is the molecular mass of the PEG 200/600. On the basis of the McMillan-Mayer theory, 36 (13) where g EN and g EEN are pair and triple Gibbs energy interaction parameters.…”