In situ one-step fabrication of superhydrophobic layered double hydroxide on Al alloys for anti-corrosion

Abstract

In this work, superhydrophobic layered double hydroxide intercalated with sodium dodecyl sulfate (LDHs-SDS) were fabricated in one-step using in situ method on the surface of 6061Al. This method is different from the previously reported secondary modification method, and truly realizes the one-step fabrication of superhydrophobic LDHs. In the experiment, the superhydrophobic properties of LDHs-SDS film are caused by the combined effect of surface roughness and surface energy. A static contact angle (CA) of 161° was observed on LDHs-SDS film, and showed excellent stability after long-term exposure to atmospheric environment and various pH. Compared with 6061Al, LDHs-SDS film can obviously elevate the corrosion potential of 6061Al while inhibiting the cathodic reaction process. The corrosion potential is increased from −0.720 V to −0.255 V (vs. SCE), and the corrosion current density is reduced from 1.3 μA to 0.02 μA. Meanwhile, the film enhanced the corrosion resistance of 6061Al from 3.2 KΩ to 70 KΩ. After corrosion, no obvious corrosion pits were observed on the surface of LDHs-SDS, which showed excellent protective performance against 6061Al.