Liquid–Liquid Equilibria for the Poly(ethylene glycol) + Water + Copper Sulfate System at Different Temperatures

Abstract

The compositions of coexisting phases have been determined for aqueous two-phase systems containing poly(ethylene glycol) of nominal molecular weight 20000 and copper sulfate at (290.15, 299.15, 308.15, and 317.15) K. The effect of temperature on the liquid–liquid equilibrium was discussed. The experimental compositions of coexisting phases of the systems were used to obtain interaction parameters in universal quasichemical theory (UNIQUAC) activity coefficient models. The experimental tie line data were compared with those obtained using the UNIQUAC model. The results of comparison were indicated by calculation of the root-mean-square deviations (rmsd). The calculated results show good agreement with the experimental data.

Equilibrium Data of the Biphasic System Poly(ethylene oxide) 4000 + Copper Sulfate + Water at (5, 10, 35, and 45) °C

“…Several authors have focused on the measurement of liquid−liquid equilibrium data of biphasic PEO with different molar masses and salt systems, as presented in Table . However, equilibrium data of PEO 4000 + copper sulfate aqueous systems are scarce in the literature . Thus, the aim of this work was to obtain phase equilibrium data of the PEO 4000 + CuSO 4 + water system at (5, 10, 35, and 45) °C.…”

“…However, equilibrium data of PEO 4000 + copper sulfate aqueous systems are scarce in the literature. 15 Thus, the aim of this work was to obtain phase equilibrium data of the PEO 4000 + CuSO 4 + water system at (5, 10, 35, and 45) °C.…”

Surface Excess Enthalpy of PEO + Salt +Water and L35 + Salt + Water Aqueous Two-Phase Systems

“…However, this approach (eq ) is not very appropriate for an aqueous two-phase systems due to the strong dependence between phase composition and temperature . So a change of the temperature promotes a change of the interfacial entropy, as calculated by eq , but also causes a modification of the interface composition.…”