Polyaniline (PANI) is one of the most intensivelyinvestigated conducting polymers due to its excellentenvironmental stability, ease of synthesis, and relativelyhigh level of electrical conductivity.
1–4 Now,PANI has been widely studied for potential applicationsin many domains such as electrochromic devices,rechargeable batteries, electromagnetic interferenceshielding, and sensors.5,6 Since the time Deberry7found the protective effect of PANI on iron-basedmetal, the anticorrosion application of PANI hasattracted enormous interest among researchers.8,9However, this has been controversially discussedamong the experts so far.
Some studies by expertssuch as by Williams and McMurray10 suggested thatconducting polymers could not be used successfully forcorrosion protection application, which reportedenhanced corrosion by PANI, and some other studiessuch as by Michalic and coworkers11,12 criticallydiscussed the corrosion protective ability of conductingpolymers. Furthermore, the benefits of PANI’s applicationare restricted by its poor solubility, as well asinfusible and almost nonprocessable properties.13 Inorder to improve the application property of PANI, anumber of methods, such as mixing of PANI withepoxy resin by mechanical dispersion to preparecomposite coatings14–18; synthesis of PANI–Na–MMTclay nanocomposites to modify the application property19; copolymerization with water-soluble polymerthrough in situ polymerization to improve the watersolubility20; and deposition on the surface of substratemetal by electrochemical techniques to protect materialfrom corrosion were studied.