Double interface reinforced durable superhydrophobic SiO2 anticorrosion coatings on etched aluminum alloys with self-cleaning and anti-fouling properties

Superhydrophobic composite coatings, composed of hydrophobic nanoparticles and adhesive, hold great potential for protecting aluminum alloys from corrosion. However, most existing coatings consider single interfacial stability. This study developed a double-interface reinforced superhydrophobic SiO 2 composite coating on etched aluminum alloys by applying the epoxy polymer (EP) primer followed by spraying a mixture of EP, polydimethylsiloxane (PDMS), and hydrophobic SiO 2 nanoparticles. The etched substrate and the intermediate EP layer effectively resolved the issue of weak interfacial bonding between the substrate and the coating, while the simultaneous incorporation of EP and PDMS ensured robust interactions within the coating itself. The resulting coating demonstrates remarkable mechanical durability and chemical stability. Notably, the coating also displays self-healing capabilities during 19 plasma cycles and provides up to 99.99 % corrosion inhibition efficiency, along with superior self-cleaning and anti-fouling properties. This study presents a novel strategy for constructing durable superhydrophobic coatings on aluminum alloys for corrosion protection.