PASSIVATION OF METALS BY COATING WITH POLYANILINE - CORROSION POTENTIAL SHIFT AND MORPHOLOGICAL-CHANGES

Corrosion protection of metals can be obtained by coating them with polyaniline dispersions, resulting in a signifiecant and reproducible shift of the corrosion potential. Scanning electron micrograph indicate that the passivation is a multistep process, beginning with an etching stage in wh8ch grain boundaries become visible (see Figure). In the second step the metal surface is coated—non‐electrochemically—with an oxide layer. The exact mechanism of formation of this layer remains to be explored. (Figure Presented.) Copyright © 1994 Verlag GmbH & Co. KGaA, Weinheim