Effect of Ce(III) and Ce(IV) ions on the structure and active protection of PMMA-silica coatings on AA7075 alloy. (15th August 2021)

• Record Type: Journal Article
• Authors: Trentin, A.; Harb, S.V.; Uvida, M.C.; Marcoen, K.; Pulcinelli, S.H.; Santilli, C.V.; Terryn, H.; Hauffman, T.; Hammer, P.
• Is Part Of: Corrosion science. Volume 189(2021)
• Publication Date: 2021-08-15
• Subjects: Organic coatings -- Inhibition -- Aluminium alloy -- Intermetallics -- EIS -- SIMS; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2021.109581
• Languages: English
• ISSNs: 0010-938X

Abstract

Graphical abstract: Highlights: Ce(IV) and Ce(III) ions improve the polymeric structure of PMMA-silica coatings. Hybrid network with <1000 ppm Ce consist of evenly spaced (3–4 nm) silica nodes. PMMA-silica-Ce(IV) coatings protect AA7075 alloy up to 700 days in 3, 5% NaCl. Only Ce(IV) provides self-healing effect due to CeO2 /Ce(OH)4 formation at pH 3. Regeneration activity is due to the dispersed form and from oxides leached Ce(IV) ions. Abstract: This work investigates the effect of Ce(III) and Ce(IV) additives on the structure and anti-corrosion properties of poly(methyl methacrylate) (PMMA)-silica coatings on AA7075 aluminium alloy. The results revealed that intermediate Ce(IV) loadings (500 and 1000 ppm) result in a dense hybrid network with a less defective polymeric phase, extending the service time of AA7075 up to 835 days in 3.5% NaCl. Although both additives provide long-term protection, the self-healing ability was observed only for Ce(IV) addition, favoured by the formation of oxides/hydroxides at pH∼3. These properties make the 4 μm-thick PMMA-silica-Ce(IV) coatings very interesting for chromium-free protection technologies.