Voltammetric and spectroscopic investigation of binding in complexes of divalent metal ions with styrene maleic acid copolymer and monomeric analogues

The interaction of divalent metal ions with styrene-maleic acid-copolymer (SMA copolymer) has been studied. Polarography, voltammetry on a hanging mercury electrode and UV-VIS spectroscopy were applied to evaluate formation constants for complexation of Cu(II), Zn(II) and Ni(II) ions with the polyelectrolyte SMA copolymer as well as monomeric dicarboxylic acids in aqueous solution, Considering adsorption of the polymer on the Hg electrode the studies show that SMA acts as strong ligand for Cu(II) ions while complexation with Zn(II) is less strong, Voltammetric behavior of Ni(II) in polymer solutions was found to be rather complex. Formation constants of Cu(II) and Zn(II) polymer complexes are considerably greater compared to the corresponding monomeric metal complexes. The results reported point to a strong influence of metal dissolution on the mechanism of deposition of MA copolymers on copper, zinc and nickel electrodes. (C) 1998 Elsevier Science Ltd. All rights reserved.