Bathocuproine-Mediated Copper Transport through Liquid Membrane Driven by Redox Potential

Abstract

A new type of carrier-mediated copper transport system driven by redox potential was studied. The two aqueous solutions of different redox potentials were separated by a polymer-supported organic liquid membrane in which Bathocuproine (L) was dissolved as a “carrier”. Copper(II) was reduced in the reducing phase to form [Cu¹L₂]⁺·X^? type complex at the membrane interface and extracted. The copper complex diffused to the other side of the membrane and decomposed to form the copper(II) species in the oxidizing phase, leaving the carrier in the membrane phase. The nature of the system under various operational conditions (pH, redox agents, pairing anions X^?, coexisting metals, etc.) was studied and compared with the metal transport system which can take place without the intervention of redox reaction. An extension of these transport reactions to water-in-oil-in-water type emulsion system was studied.