SENSITIVITY OF POLY 1,8-DIAMINONAPHTHALENE TO HEAVY-METAL IONS - ELECTROCHEMICAL AND VIBRATIONAL-SPECTRA STUDIES

The sensitivity of poly(1,8-diaminonaphthalene) [poly(1,8-DAN)] to hea vy metal ions (Ag+, Hg2+, Cu2+) was studied by means of electrochemica l (open circuit potential (ocp), cyclic voltammetry) and spectroscopic methods (IR, Raman spectra). Changes of the open circuit potential of the polymer electrode indicate that Ag+ and Hg2+ ions are able to oxi dise poly(1,8-DAN), while Cu2+ ions do not influence the ocp of the po lymer. Cyclic voltammograms of poly(1,8-DAN) give direct evidence that Ag+ ions are reduced at the polymer surface whereas Hg2+ or Hg-2(2+) ions are bonded by the polymer matrix. IR and Raman spectra indicate t hat Cu2+ and Hg2+ or Hg-2(2+) ions are complexed by the amino groups o f the polymer. (C) 1997 Elsevier Science B.V.