Article ID Journal Published Year Pages File Type
673742 Thermochimica Acta 2013 8 Pages PDF
Abstract

Liquid–liquid equilibrium data of aqueous two-phase systems (ATPSs) formed by poly(ethylene glycol) (PEG) of different molecular weights (1000, 2000, 6000) + ammonium carbonate ((NH4)2CO3), ammonium tartrate ((NH4)2C4H4O6), diammonium hydrogen phosphate ((NH4)2HPO4), ammonium sulfate ((NH4)2SO4) + water were determined at 298.15 K, respectively. The binodal data were correlated by using a four-parameter equation. The effect of PEG molecular weight on binodal curves was investigated, and it was found that the biphasic region expanded with an increase in PEG molecular weight. Meanwhile, it was also observed that the ability of the investigated salts for phase separation follows the order: (NH4)2HPO4 > (NH4)2SO4 > (NH4)2C4H4O6 > (NH4)2CO3. Furthermore, a relatively simply two parameter equation, Othmer–Tobias and Bancroft equations was successfully used to correlate the tie-line data.

► The binodal/liquid–liquid equilibrium data of PEG + several ammonium salts + water ATPSs were determined experimentally. ► Some appropriate equations were satisfactorily used to correlate the binodal curves and the tie-lines. ► The salting-out ability of the investigated salts follows the order: (NH4)2HPO4 > (NH4)2SO4 > (NH4)2C4H4O6 > (NH4)2CO3. ► The effect of PEG molecular weight on binodal curves was discussed.

Related Topics
Physical Sciences and Engineering Chemical Engineering Fluid Flow and Transfer Processes
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