Enhanced corrosion resistance and mechanical stability of superhydrophobic micro-nano particles/epoxy coatings for the protection of cements

As an advanced protective material, superhydrophobic coatings utilize their distinctive surface properties to effectively prevent moisture and other corrosive substances from directly contacting the substrate, thereby significantly enhancing its service life. This study introduces a robust superhydrophobic coating specifically designed for cement-based substrates. The coating system, developed through a two-step fabrication process, primarily comprises quartz sand and nanomaterials with hierarchical structures. Comprehensive evaluations were conducted focusing on abrasion resistance, corrosion resistance, UV aging resistance, and freeze-thaw cycle durability. Notably, the 12 wt.% nano-Al₂O₃ coating prepared via two dip-coating cycles (12Al-2D coating) demonstrated superior hydrophobicity and stability. The 12Al-2D coating achieved remarkable surface properties with a contact angle of 153° and an ultra-low sliding angle of 1.8° Under sandpaper abrasion, the coating retained a contact angle >150° after 50 friction cycles, demonstrating exceptional wear resistance. Additionally, the 10 wt.% nano-SiO₂ coating fabricated through three dip-coating cycles (10Si-3D coating) attained a hardness level of 6H Both coatings displayed strong adhesion. After 50 freeze-thaw cycles, the 12Al-2D coating retained a contact angle of 140°, demonstrating robust environmental adaptability. In simulated corrosive environments, the coatings exhibited excellent durability without significant corrosion damage. The 12Al-2D coating maintained its hydrophobic characteristics, providing effective protection for the substrate. This research provides valuable insights and innovative strategies for the corrosion protection of cements.