ANION-EXCHANGE ACTIVITY OF ELECTROCHEMICALLY BONDED ETHYLENE DIAMINE ON CARBON-FIBERS

Carbon fibre based anion exchangers were prepared through electrochemical oxidation and bonding of ethylene diamine on fibre electrodes in acetonitrile and subsequent formation of the chloride salts of the ammonium groups. Catalytically active noble metals can be introduced into the carbon matrix after ion-exchange with complex salts, carrying the noble metal in their anionic component, and subsequent cathodic reduction of the noble metal ions to the metallic state, in aqueous solutions. The free amino groups of the carbon fibres modified with oxidized ethylene diamine can be used for the preparation of chemically modified electrodes via an amidization reaction with acid chlorides. The amount of the oxidized ethylene diamine attached to the carbon fibre surface exceeds a monolayer coverage, suggesting the formation of chain and bridge configurations on the carbon fibres. Investigation was performed by cyclic voltammetric, chrono-amperometric, potentiometric and impedance measurements. The order of magnitude of the anion-exchange capacity of the produced material for small anions was 1 meq per g carbon fibre.