Construction of MOF-based superhydrophobic composite coating with excellent abrasion resistance and durability for self-cleaning, corrosion resistance, anti-icing, and loading-increasing research

A superhydrophobic composite coating was facilely constructed based on MOF (ZIF-8) nanoparticles and organic resin. Hydrophilic ZIF-8 nanoparticles with hydroxyl group were firstly prepared in aqueous media at room temperature, and then modified with low surface energy perfluorooctyltriethoxysilane (POTS) through hydrolytic condensation to give a superhydrophobic paint. Additionally, epoxy resin (EP) was innovatively introduced as adhesive layer to improve the robustness and adhesive force of the superhydrophobic coating. The as-prepared ZIF-8/POTS/EP composite coating showed high water-repellency (water contact angle = 168.2°), mechanical and chemical robustness, and durability that it could maintain the superhydrophobicity after weathering in air for 300 days or immersing in 3.5 wt% NaCl aqueous solution for 60 days. The superhydrophobic composite coating also possessed excellent performance in self-cleaning, corrosion resistance, anti-icing and loading-increasing. Noteworthily, for the corrosion resistance, the ZIF-8/POTS/EP coating could increase the impedance modulus (at 0.01 Hz) of Q235 steel by about 7 orders of magnitude after immersion in 3.5 wt% NaCl aqueous solution for 7 days. We believe that this work can not only promote the effortless and large-scale preparation of superhydrophobic surface and their practical applications in future, but also provide a novel way for applying MOF materials into more fields.