SALTING-OUT EFFECT IN PEG-BASED AQUEOUS BIPHASIC SYSTEMS IN THE PRESENCE OF IONIC LIQUIDS AS ADDITIVES

ABS are able to provide, during the last two decades, ionic liquid (IL)–salt ABS have been proposed. In recent years, with the aim of using the high extraction efficiencies exhibited by ILs, but with lower IL amounts, a new approach based on the use of ILs as additives in conventional polymer–salt ABS has been proposed. For designing and operating aqueous two-phase extraction processes, the availability of information about the phase behavior of ABS is of great importance. Therefore, in this work novel ABS composed of polyethylene glycol 400 (PEG 400) and potassium carbonate (K2CO3) or ammonium sulfate ((NH4)2SO4) using the IL 1-butyl-3-methyl-imidazolium bromide ([C4C1im]Br) as additive (at 5 wt%) were studied. The binodal curves were determined at T = 298.15 K. Furthermore, the salting-out effect and the consequent ABS formation were examined on the basis of the ionic viscosity B-coefficients of the Jones-Dole equation.