Performance of Superhydrophobic Nano Complex Anti- corrosion Coating Fabricated by Sol-gel Technique

Abstract

Superhydrophobic complex coatings of mesoporous carbon/silica on stainless steel were prepared by a sol-gel spin cast method. The morphologies, anticorrosion property and hydrophobic- ity of the coatings were characterizd by means of scanning electron microscopy (SEM) and trans- mission electron microscopy (TEM), electrochemical test technique-Tafel curve and electrochemi- cal impedance spectroscopy, as well as water contact angle measurement (CA) respectively. The coatings exhibited varied surface morphologies with bump-like and nipple-like protrusions on the stainless steel substrate. The coatings had a high water contact angle larger than 163°, indicating its strong hydrophobicity. The corrosion current density of the superhydrophobic complex coating coated steel was 8 order of magnitude lower than the bare steel, while its charge transfer resistance (Rct) was 6 order of magnitude higher as well, implying an excellent corrosion protectiveness. Be- sides, an electrochemical equivalent circuit was proposed to interpret the relevant anti-corrosion mechanism for the superhydrophobic coatings.