Durable fluorine-free superhydrophobic coatings enabled by microwave-assisted ball milling of octadecylamine-graphene oxide

Superhydrophobic coatings exhibit significant potential for various applications, but their practical application is hindered by poor durability. Achieving high durability often relies on fluorinated reagents, posing environmental pollution risks. Herein, a fluorine-free strategy for fabricating durable and environmentally friendly superhydrophobic coatings was proposed to address these challenges. Octadecylamine-functionalized graphene oxide (ODA-GO) without fluorine compounds was synthesized via microwave-assisted ball milling. Subsequently, a superhydrophobic coating was established by spraying a mixture of ODA-GO, epoxy resin, and polydimethylsiloxane. The resulting coating demonstrated high superhydrophobicity, with a water contact angle greater than 161° on various substrates, and outstanding durability. After immersion in chemical solvents (NaCl, HCl, NaOH) for 24 h, prolonged ultraviolet (UV) irradiation, high-temperature exposure, and a series of mechanical stability tests, including tape peeling, sandpaper abrasion, sand impact, and water impact, the coating consistently maintained its superhydrophobic properties. Furthermore, the coating achieved a polarization resistance of 1.76 × 10 6 Ω·cm 2 after 21 days in a 3.5 wt% NaCl solution and maintained a high oil-water separation efficiency of up to 98 %. This work provides a green, fluorine-free approach for highly durable superhydrophobic coatings, paving a potential path for their practical applications in marine anti-corrosion and protective coatings for industrial equipment.