Insitu growth of durable superhydrophobic Mg–Al layered double hydroxides nanoplatelets on aluminum alloys for corrosion resistance

Abstract

A series of superhydrophobic aluminum alloys covered with Mg–Al layered double hydroxide (LDH) films were fabricated by a simple hydrothermal method. The as-prepared metal surface showed excellent superhydrophobicity, corrosion inhibition and mechanical robustness. The morphology and phase composition of the as-prepared films were studied by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). SEM and EDS results showed that the homogeneous micro/nanoscale hierarchical films are predominantly verticality to the substrate and cover almost all over the surface, which composed of Mg–Al LDHs nanoplates structures. The static water contact angle (WCA) for the prepared surface was observed at around 160°. The phase structure of the Mg–Al LDH films was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that the LDHs nanoplatelets were preferentially formed on the surface of aluminum alloy, which led to an effective healing of the film defects. The corrosion resistance of Mg–Al LDH covered alloy surface was studied by means of electrochemical corrosion tests. Compared with that of bare aluminum alloy sample (1.584 × 10−4 A/cm2), the calculated corrosion current density of superhydrophobicity aluminum alloy surface was 1.585 × 10−5 A/cm2, which showed highly improved corrosion resistance. Further, the results of mechanical durability and anti-icing tests indicated the modified hierarchical alumina alloy surfaces exhibit excellent mechanical durability and anti-icing properties, rendering an excellent active protection for the LDH films covered aluminum alloy substrate.