The differences between
|Z|0.01 Hz values remain low (less
than one decade) and, thus, questionable. FTIR–ATR spectroscopy
will provide later in the paper, the same conclusions regarding the effect of PANI pigments on barrier properties.
When immersion
time increases, the
|Z|0.01 Hz of the coating with no PANI decreases
sharply after 1 day of exposure, and then gradually decreases to
reach values below 106cm2 after 21 days of exposure. The initial
quick decrease in
|Z|0.01 Hz may be due to water ingress into
the coating while the subsequent decrease is related to delamination
and corrosion of the steel substrate