Novel extraction of metal ions from acidic media using poly(ethylene oxide) phases

Abstract

A novel type of extraction system based on poly(ethylene oxide) (PEO) has been developed. Interaction of the aqueous solution of PEOs and trichloroacetic acid (TCA) leads to the formation of a second liquid phase without the addition of any organic diluent. Liquid associates of PEOs with trichloroacetic acid show excellent Pb²⁺ and Ba²⁺ extraction from strongly acidic media. The same effect was also observed on the surface of the polystyrene beads, coated with poly(ethylene oxide) chains. Both liquid and solid systems based on PEO associates demonstrate quantitative extraction of GaIII, FeIII, InIII, AuIII and TlIII from various acidic solutions. High extraction of TcO₄^– is expected on the basis of ReO₄^– extraction. PEOs present an environmentally acceptable, inexpensive alternative to standard solvent extraction systems for metals separation.