Preparation of Fe3O4/PANI nanocomposite and its metal anticorrosive activity

Spherical Fe 3 O 4 /polyaniline(PANI) nanocomposites with core-shell structure were prepared by oxidative polymerization of aniline on the Fe 3 O 4 − /aniline(ANI) + nanocomposite template formed by the electrostatic interaction between nano-Fe 3 O 4 and aniline salt. FTIR and UV–Vis results indicate that there is coordination interaction between Fe 3 O 4 and PANI interface. SEM and TEM results show that the thickness of PANI shell increases with the increase of aniline/Fe 3 O 4 mass ratio. Compared with PANI, Fe 3 O 4 /PANI nanocomposites maintain obvious redox activity in neutral medium. The organic composite coating was prepared by filling Fe 3 O 4 /PANI nanocomposites into waterborne acrylate/amino baking paint. The results show that the composition ratio of aniline/Fe 3 O 4 has a great influence on the metal anticorrosive activity of Fe 3 O 4 /PANI nanocomposites. The long-term metal corrosion resistance of Fe 3 O 4 /PANI(1:2) composite coating is three times as compared with unfilled organic coating. The metal anticorrosive mechanism of Fe 3 O 4 /PANI nanocomposites has been revealed to be the excellent nano-barrier effect and the metal surface passivation. • Fe 3 O 4 /PANI with spherical core-shell structure were prepared by electrostatic interaction of Fe 3 O 4 /ANI + template. • 1% (mass fraction) of Fe 3 O 4 /PANI (1:2) significantly improved the waterborne coating corrosion protection. • The metal anticorrosion mechanism of Fe 3 O 4 /PANI is the effective nanobarrier effect and metal passivation catalysis.