From Surface-Limited to Bulk-Enabled Superamphiphobicity via a Self-Similar Coating Architecture

Superamphiphobic coatings are prone to abrupt wetting failure in high-wear environments owing to the destruction of surface micro/nano-structures, which limits their durability in practical applications. Here, a gradient self-similar structure along the coating thickness is designed and realized via spray deposition, enabling continuous distribution of functional fillers so that newly exposed interfaces during wear retain micro/nanoscale roughness and low-surface-energy chemistry similar to those of the original surface. This design converts abrupt wetting failure into a gradual and controllable degradation process, thereby achieving "bulk inheritance" of the superamphiphobic function. Consistent with this bulk-inheritance mechanism, the coating exhibits markedly enhanced wear resistance and wetting retention under severe Taber abrasion and particle impact compared with conventional surface-engineered superamphiphobic coatings. In addition, the gradient architecture provides an effective electrochemical barrier, endowing the coating with excellent corrosion protection. This work establishes a self-similar structural strategy to regulate the failure behavior of superamphiphobic coatings, offering a pathway toward durable performance in high-wear environments.