Polyaniline (PANI) is one of the most intensively
investigated conducting polymers due to its excellent
environmental stability, ease of synthesis, and relatively
high level of electrical conductivity.1–4 Now,
PANI has been widely studied for potential applications
in many domains such as electrochromic devices,
rechargeable batteries, electromagnetic interference
shielding, and sensors.5,6 Since the time Deberry7
found the protective effect of PANI on iron-based
metal, the anticorrosion application of PANI has
attracted enormous interest among researchers.8,9
However, this has been controversially discussed
among the experts so far. Some studies by experts
such as by Williams and McMurray10 suggested that
conducting polymers could not be used successfully for
corrosion protection application, which reported
enhanced corrosion by PANI, and some other studies
such as by Michalic and coworkers11,12 critically
discussed the corrosion protective ability of conducting
polymers. Furthermore, the benefits of PANI’s application
are restricted by its poor solubility, as well as
infusible and almost nonprocessable properties.13 In
order to improve the application property of PANI, a
number of methods, such as mixing of PANI with
epoxy resin by mechanical dispersion to prepare
composite coatings14–18; synthesis of PANI–Na–MMT
clay nanocomposites to modify the application property
19; copolymerization with water-soluble polymer
through in situ polymerization to improve the water
solubility20; and deposition on the surface of substrate
metal by electrochemical techniques to protect material
from corrosion were studied.