News Coatings Technologies
Self-healing superhydrophobic LDH films enhance aluminium corrosion protection
Researchers report in situ ZnAl-LDH conversion layers on aluminium that self-heal via tungstate intercalation. After fluorosilane modification, the contact angle reaches 171 ° and protective efficiency 99.9 %, remaining 99.6 % after 80 days in NaCl solution.
The study details the fabrication of ZnAl layered double hydroxide (LDH) films directly on aluminium surfaces. Tungstate intercalation (LDH-W) combined with fluorosilane treatment yields a superhydrophobic surface. Scanning electron microscopy shows a uniform, dense lamellar structure; neither intercalation nor FAS treatment compromises morphology. The water contact angle reaches 171 °.
Electrochemical impedance spectroscopy indicates a protective efficiency of 99.9 %, which remains at 99.6 % after 80 days of immersion in NaCl solution. Artificially scratched samples exhibit pronounced self-healing as released tungstate ions trigger a dense oxide layer on aluminium, repairing the barrier.
Reading tip: Corrosion protection coatings
The book “Anticorrosive Coatings: Fundamentals and New Concepts” brings together all the disciplines involved in the creation and use of corrosion protection coatings for metals. It presents the latest insights into the quality and chemistry of surfaces, the proper way to prepare them by conversion treatment, the function of resins and anticorrosion pigments in paints, and novel concepts in corrosion protection. As an added bonus, all the standards and directives mentioned in the text are grouped together in their own chapter for a better overview.
Mechanism and application outlook
The mechanism relies on inhibitor release from the LDH interlayer followed by oxide re-formation. Overall, the system addresses requirements for chromate-free conversion layers while adding superhydrophobicity to reduce wetting and permeation.
Source: Wang, Y., Gao, X., He, W. & Ma, H., Fabrication of self-healing superhydrophobic film via inhibitor loaded LDH for improving the anti-corrosion performance of aluminum alloy. Progress in Organic Coatings 207, 109418 (2025).
