Enhanced mechanical durability in superhydrophobic coatings: A primer-topcoat strategy with PVDF and hydrophobic Fe2O3 nanoparticles

Superhydrophobic surfaces are widely recognized for their exceptional anti-fouling and self-cleaning properties, making them suitable for diverse applications. However, their fragile micro-nano structures are susceptible to mechanical damage, leading to a progressive loss of superhydrophobicity. To address this limitation, a novel superhydrophobic coating exhibiting robust mechanical stability through a primer-topcoat strategy. The coating comprises a top layer of fluorocarbon resin/hydrophobic iron oxide nanoparticles, bonded to an epoxy-based adhesive underlayer. This design provides superior liquid repellency (CA > 150°) and enhances substrate adhesion. The resulting coating demonstrates exceptional durability, maintaining its superhydrophobicity even after extensive abrasion (over 1000 cycles), high-temperature exposure (400°C), and prolonged immersion in strongly alkaline environments (over 120 h). This study presents a straightforward yet effective method for fabricating durable superhydrophobic coatings that retain long-term self-cleaning and anti-fouling performance under harsh conditions. The developed system exhibits broad application potential for scenarios demanding robust surface functionality.