Durable superhydrophobic coatings based on CNTs-SiO2gel hybrids for anti-corrosion and thermal insulation
Xing Shen, Tianci Mao, Changquan Li, Fei‐Fei Mao, Zhiye Xue, Guoqiang Xu, Alidad Amirfazli
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-SiO 2 gel 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-SiO 2 gel hybrids superhydrophobic coating is 1.55 × 10 −7 A/cm 2 is three orders of magnitude lower than steel plate (1.07 × 10 −4 A/cm 2 ), indicating that CNTs-SiO 2 gel hybrids have excellent corrosion resistance . CNTs-SiO 2 gel hybrids superhydrophobic coating has achieved certain thermal insulation performance compared with ordinary CNTs-SiO 2 coating. CNTs-SiO 2 gel hybrids superhydrophobic coating, which has both anti-corrosion and thermal insulation capabilities, will certainly expand the practical application of superhydrophobic coating.