Voltammetric investigation of polyelectrolyte-Cu(II) complexes

The complexation behaviours of poly(N-vinylcarbazole) (PNVCz), poly(acrylic acid) (PAA) poly(itaconic acid) (PIA) and their copolymers, synthesized by using different initial monomer compositions, with Cu(II) ions were investigated by the voltammetric technique. Their solutions were prepared in THF-water mixture according to the water-insoluble nature of PNVCz and its copolymers. The polymeric ligand-Cu(II) interactions, i.e. complex formations were studied as a function of copper ion concentration and copolymer composition. It was observed that although the cyclic voltammogram (CV) of Cu(II) alone in THF-water mixture was characterized by one redox wave, which has an irreversible nature, it became more reversible in the presence of polymer. Further, the CV results indicated the presence of two different electron transfer mechanisms, depending on the n _COOH/n _Cu(II) ratio and the carboxyl content of the copolymers.