Fabrication of stable superamphiphobic coatings based on palygorskite nanorods for anti-adhesion and anti-icing

Abstract Compared with superhydrophobic coatings, superamphiphobic coatings offer broader application potential in various fields. However, their practical applications are often hindered by insufficient repellency towards low-surface-tension, high-viscosity and complex multicomponent liquids, as well as by their stability. Herein, a palygorskite-based stable superamphiphobic coating with a simple fabrication process and low cost is reported. The coating was fabricated through sequential spray deposition of a fluorosilicone resin (FSR) bonding layer and a superamphiphobic functional layer composed of fluorinated palygorskite (F-PAL), fluorinated carbon black (F-CB) and FSR. In this coating, F-PAL nanorods serve as the building blocks for constructing the primary nanostructure, while F-CB nanoparticles occupy the interstitial spaces between the PAL nanorods, forming the secondary nanostructure. Together, these components generate a multiscale hierarchical micro-/nanostructure that is critical for achieving superamphiphobicity. By systematically optimizing the mass ratio of F-CB to F-PAL and the FSR content, a low-surface-energy multiscale hierarchical micro-/nanostructure was successfully established, imparting the coating with excellent superamphiphobicity towards water, hydroxyl-terminated polybutadiene/dioctyl sebacate mixtures (HTPB-H) and their aluminium powder-containing suspensions (HTPB-H/Al). The coating exhibits outstanding mechanical, chemical and thermal stability. Furthermore, the coating demonstrates remarkable anti-adhesion performance against both HTPB-H and HTPB-H/Al, together with superior passive anti-icing performance, as evidenced by a significantly prolonged freezing delay time (1291 s, ∼30-fold increase) and a substantially reduced ice adhesion strength (from 224.3 to 65.8 kPa). Moreover, efficient photothermal de-icing performance was achieved under low-temperature, high-humidity and weak-light conditions. These results demonstrate that the proposed superamphiphobic coating holds significant promise for practical applications in anti-adhesion and anti-icing under harsh conditions.