Hierarchically structured carbon nanotube–polyaniline nanobrushes for corrosion protection over a wide pH range

Abstract

Carbon nanotube–polyaniline brush-like nanostructures have been successfully synthesized through in situ oxidative polymerization of aniline on the surface of carboxylated multi-walled carbon nanotubes. The diameter of the resultant tubular nanobrushes is dependent on the mass ratio of c-MWNTs to aniline. The as-designed carbon nanotube–polyaniline nanobrushes exhibit superior electroactivity not only in acidic, but also in neutral and alkaline environments. The excellent anticorrosion performance has been achieved by incorporation of these nanobrushes into amine cured epoxy modified acrylic resin. It is found that the good barrier property of the nanobrush coating against neutral and alkaline corrosion media penetration and its predominant passivation protection against acidic medium offer anticorrosion protection for steel over a wide pH range. The novel carbon nanotube–polyaniline nanobrushes prepared using this facile route extend the application of polyaniline to a wider range of pH environments and facilitate a more environmentally friendly and economical system than traditional heavy metal coatings and their oxide coatings, in the application of anticorrosion protection of metals.