Hydrophobic polyaniline/modified SiO2 coatings for anticorrosion protection

•The modified SiO2 using a grafting process can effectively filled the gaps of the electrospun PANI coating.•The corrosion protection efficiency of electrospun PANI/modified SiO2 coatings increase with the hydrophobicity of modified SiO2.•Especially, the PANI/SiO2-DTMS coatings with a self-repairing function still show an impressive anticorrosion efficiency after 71 days immersion.

In this work, hydrophobic polyaniline (PANI)/modified SiO2 composite coatings were prepared by drop-casting modified silica onto electrospun PANI coatings. The PANI/modified SiO2 composite coatings showed excellent corrosion protection properties. The superior protection property of the PANI/modified SiO2 coatings could be ascribed to the synergistic effect of three factors as follows: the electrochemical activity of PANI, the efficient filling of modified SiO2 nanoparticles into the voids of the electrospun PANI coating, and the high hydrophobicity of the hybrid PANI/modified SiO2 coatings. Specifically, the results indicate that PANI/modified SiO2 by the dodecyltrimethoxysilane (PANI/SiO2-DTMS) (CA = 95°) coating has a self-repairing function and shows an anticorrosion efficiency of 99.99% for Q235 carbon steel, which was maintained at 99.99% after 71 days of immersion in 0.1 M H2SO4.