Mc. Bernard et al., Protection of iron against corrosion using a polyaniline layer - III. Spectroscopic analysis of the mechanisms accompanying the breakdown, J ELCHEM SO, 148(8), 2001, pp. B304-B306
The protection of iron against corrosion brought by polyaniline (PANI) pote
ntiostatically polymerized in phosphoric/metanilic solution is due to the c
ombination of the passive layer and the polymer. The passive layer is stren
gthened by phosphate incorporation, and sulfonated aniline is inserted in t
he chain to yield a copolymer (SPAN). The potentiostatic polarization is pa
rtly responsible for the heterogeneity of polymer (block-polymer). Raman an
d optical spectroscopies are used to characterize the modifications in the
PANI composition preceding and accompanying the passivity breakdown. The br
eakdown is associated with the loss of PANI reoxidability, but this step is
preceded by slow modifications in the polaron distributions. (C) 2001 The
Electrochemical Society.