Durable superhydrophobic coatings based on CNTs-SiO2gel hybrids for anti-corrosion and thermal insulation

Abstract

When steel structure buildings appear more frequently in our lives, the anti-corrosion and thermal insulation capacity of steel as the substrate is an inevitable difficult problem. To solve this problem, we propose a carbon nanotube silica aerogel hybrid (CNTs-SiO2gel hybrids), which is a new type of nanoparticle obtained by grafting the modified silica aerogel onto carbon nanotubes. After that, the superhydrophobic coating was prepared on Q235 steel by simple one-step spraying. The prepared superhydrophobic coating has a stable micro nanolayered structure and excellent hydrophobicity, with a contact angle of 168.7 ± 1°and a sliding angle of 4.5 ± 0.4°. The superhydrophobic coating can withstand various mechanical and chemical durability tests and maintained good superhydrophobic properties. The electrochemical experimental analysis shows that the corrosion current density of CNTs-SiO2gel hybrids superhydrophobic coating is 1.55 × 10−7 A/cm2 is three orders of magnitude lower than steel plate (1.07 × 10−4 A/cm2), indicating that CNTs-SiO2gel hybrids have excellent corrosion resistance. CNTs-SiO2gel hybrids superhydrophobic coating has achieved certain thermal insulation performance compared with ordinary CNTs-SiO2 coating. CNTs-SiO2gel hybrids superhydrophobic coating, which has both anti-corrosion and thermal insulation capabilities, will certainly expand the practical application of superhydrophobic coating.