Mesh-Armored Re-Entrant Structures via Solvent Evaporation-Induced Fragmentation for Abrasion-Durable Super-Repellent Surfaces.

Abstract

Super-repellent surfaces hold significant potential in engineering applications such as self-cleaning, antifouling, and drag reduction. However, their practical implementation has been hindered by challenges in scalable fabrication and mechanical fragility. This study presents an innovative and scalable strategy to fabricate hierarchical micro-nano re-entrant structures using a stainless-steel mesh framework. By dip-coating the mesh in a nanoparticle-incorporated superhydrophobic coating, it is observed that the superhydrophobic mesh re-entrant (SHM-R) structures spontaneously form within mesh pores through solvent evaporation-induced membrane fragmentation. The SHM-R surface exhibits exceptional super-repellency, with a water apparent contact angle of 160.3 ± 1.6° (sliding angle 0.9 ± 0.3°) and a 30% ethanol apparent contact angle of 150.6 ± 4.6° (sliding angle 7.4 ± 3.1°). Crucially, the mesh framework acted as mechanical armor, protecting the re-entrant structures from abrasion, enabling the surface to retain its liquid-repellent properties even after 100 abrasion cycles under 12.3 kPa pressure-a durability breakthrough compared to conventional re-entrant surfaces. Furthermore, the SHM-R surface demonstrates robust underwater plastron stability, achieving a ≈100% improvement in water pressure resistance while maintaining stable plastron coverage under pressure fluctuations. The excellent gas spreading behavior of SHM-R enables capillary-driven air self-suction to rapidly replenish damaged plastrons. This work provides an important insight for the scalable design of robust super-repellent surfaces.