Superhydrophobic and smart MgAl-LDH anti-corrosion coating on AZ31 Mg surface

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) 2021, 103(0), , pp.154-164
• Main Authors: Huang, Manyi, Lu, Guangming, Pu, Jibin, Qiang, Yujie
• Format: Article
• Language: English
• Subjects: Active protection; Corrosion resistance; LDH; Superhydrophobic coating; Surfactant; 화학공학
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2021.07.031

[Display omitted] •Convenient in-situ preparation strategy of MgAl-LDH coatings on Mg was proposed.•The prepared superhydrophobic coating has long-lasting anti-corrosion performance.•The anti-corrosion mechanism of MgAl-LDH coatings modified by different long-chain molecules has been clarified. Layered double hydroxides (LDHs) have been widely used as “smart” containers in the field of metal corrosion protection, and have broad industrial prospects. It is environmentally friendly and feasible to use aliphatic carboxylates and corresponding acids as substitutes for harmful corrosion inhibitors. However, previous studies rarely involved comparing the anti-corrosion mechanisms of different aliphatic acids modified on the LDH surface, and the durability of the prepared coatings also needs to be improved. In this work, MgAl-LDH laminates were grown in situ on AZ31 substrates by a hydrothermal method, and then modified by sodium laurate (SL) and sodium dodecylbenzene sulfonate (SDBS). Due to the physical barrier effect of the LDH layers, the spatial repulsion effect of the air film and the ion exchange reactions in the interlayer galleries, the functional coatings prepared exhibit smart and superior anti-corrosion performance on the magnesium substrates in 3.5 wt.% NaCl solution. Compared with LDH-SDBS-8 coating, the obtained superhydrophobic LDH-SL-8 coating shows more excellent long-term corrosion protection owing to the stronger intercalation capacity.