Poly(ethylene glycol)-based aqueous biphasic systems: effect of temperature on phase equilibria and on partitioning of 1,10-phenanthroline-copper(II) sulphate complex.

Solvent extraction is a proven technology for the selective removal and recovery of metal ions from aqueous solutions: the use of aqueous biphase systems can be attractive for many separation processes. These systems have usually been used previously at temperatures around 25 degrees C; however it is possible that better separations may be achieved at other temperatures: phase diagrams have been determined for a polyethylene glycol (AMW 3350)-ammonium sulphate-water system over the temperature range 269-343 K and the effect of temperature on partitioning has been determined for 1,10-phenanthroline-copper(II) sulphate complex.