A novel superhydrophobic composite coating based on DTMS modified MSNs containers for active protection of aluminum alloys

Superhydrophobic coatings hold great promise for protecting aluminum alloys from corrosion. However, most existing coatings offer only short-term passive protection, with limited attention to their long-term efficacy. In this study, dodecyltrimethoxysilane (DTMS)-modified mesoporous silica nanoparticles (SH-MSNs) were selected for the first time as the containers of benzotriazole (BTA). The resulting SH-MSNs@BTA was then incorporated into epoxy resin to create a functional primer, which was then combined with a superhydrophobic silica (SH-SiO 2 ) topcoat to develop a superhydrophobic composite coating system (ESMSS@BTA) that provides both active and passive protection to aluminum alloys. Due to the synergistic effect of excellent water repellency, dense primer structure, and self-healing of BTA, the ESMSS@BTA coating exhibits higher anti-corrosion performance than the coating without BTA loading after immersion in 3.5 wt% NaCl solution for up to 30 days. Additionally, the mechanical stability of the ESMSS@BTA coating, along with the tolerance to either alkaline or acid media, was evaluated to assess its durability. This research is expected to provide new ideas for designing superhydrophobic coatings for long-lasting protection of metals.