Magnesium alloy has significant advantages in lightweighting and is widely used in aviation, automobiles, and electronic devices. However, its electrode potential is extremely low, and it is prone to uneven and continuous corrosion in chlorine-containing environments. Traditional epoxy resins rely solely on physical barriers and a single corrosion inhibitor filler is prone to being depleted quickly. The corrosion of magnesium alloys is divided into two stages: an initial intense stage and a later stable stage. The existing coatings cannot match the dynamic evolution pattern of corrosion, resulting in a significant shortcoming in long-term protection life. The porous structure of diatomite and the high drug-loading potential of ZIF-8 have been used separately, lacking a hierarchical composite system to simultaneously achieve long-term barrier and on-demand release.
Professor Zhang Yuxin's team from Chongqing University, specializing in new silicon algae material innovation, used natural diatom (DE) as the base to in-situ grow layered hierarchical SZIF-8 carriers, loaded sodium molybdate corrosion inhibitor to construct Na₂MoO₄@SZIF-8-DE intelligent filler, and combined with E51 epoxy resin to prepare an adaptive anti-corrosion coating.
- Material structure innovation: Through water phase regulation, two-dimensional sheet-like ZIF-8 is uniformly coated with silica algae, forming micro-to-intermediate pore channels. The loading amount of corrosion inhibitor reaches 12.49%, and the fillers do not aggregate in the epoxy and have excellent interface bonding.
- pH sequential release: In acidic corrosive environments, molybdate is rapidly and abundantly released to inhibit the initial intense corrosion. In neutral/weakly alkaline environments, it is released slowly and over a long period to provide sustained replenishment, perfectly matching the two-stage characteristics of magnesium alloy corrosion.
- Excellent anti-corrosion performance: The 10 wt.% filler composite coating maintained ultra-high and low-frequency impedance after being immersed in a 3.5 wt.% NaCl solution for 60 days. Molecular dynamics simulation confirmed that the free volume of the coating and the diffusion coefficient of the corrosive medium decreased significantly; the scratch salt spray test can in situ generate a dense magnesium molybdate passivation film, demonstrating the potential for self-repair.
- Multiple synergistic advantages: Diatom extends the penetration path of corrosive ions, SZIF-8 provides a pH-responsive channel, molybdate and Mg²⁺ spontaneously form a stable protective film, while enhancing the coating's wear resistance and interface adhesion.
This work breaks through the traditional static anti-corrosion thinking and establishes a new strategy of corrosion evolution-matched time-sequenced slow-release protection. It provides a brand-new design scheme for the long-term anti-corrosion coating of lightweight magnesium alloys in aviation and transportation. The related results have been published in Nano Research on June 22, 2026.
About the Authors
Professor Zhang Yuxin's Profile
Professor and PhD Supervisor at Chongqing University's School of Materials Science and Engineering, Chief of Silago New Materials at Mingyue Lake Laboratory and Executive Deputy Editor of Nano Material Science, he is a Clarivate Highly Cited Researcher on Stanford University's Top 2% Global Scientists list, a Chongqing academic and young scientific leader, Fellow of the Royal Society of Chemistry and Shandong Taishan Industrial Leading Talent. Focused long-term on silago biomimetic nanocomposites, metal alloy long-term anti-corrosion, environmental functional materials and extreme-environment military-civilian infrastructure research, he has undertaken over 20 national/provincial projects with 29,338 citations and an H-index of 96, claiming multiple provincial-ministerial first prizes including the 2022 Chongqing Natural Science First Prize and 2021 Non-metallic Mineral Science and Technology First Prize as the first completer. He develops an integrated undergraduate-postgraduate training system, built a silago materials innovation platform and guided students to win national "Internet +" competition gold, published two academic monographs and one popular science book on silago, and built interdisciplinary pilot platforms with aerospace and new materials enterprises to boost industry-university-research collaboration.
Diatom New Materials Innovation Team
The team has established a complete platform for material synthesis - multi-scale characterization - theoretical calculation based on the School of Materials Science and Engineering of Chongqing University, the National Key Laboratory of Mountain and Earthquake Engineering Safety, and the Mingyue Lake Laboratory. The core directions include the modification of natural diatom minerals, composite intelligent corrosion inhibitors, lightweight metal long-term protective coatings, and biomimetic functional materials. The team has published a series of results in top journals such as Nano-Micro Letters, Advanced Powder Materials, Nano Research
