Corrosion resistant coatings from bio-derived sodium alginate and inorganic components for metallic materials

T. Moskalewicz, M. Warcaba, A. Ɓukaszczyk
AGH University of Science and Technology,

Keywords: sodium alginate, graphite oxide, coating, adhesion strength, corrosion resistance


It is crucial to enhance the resistance of metallic materials to electrochemical corrosion. One promising strategy is the deposition of polymeric coatings. Sodium alginate, a natural hydrophilic polysaccharide is a biocompatible and biodegradable component of marine brown algae. Therefore, it can be used in biomedical engineering and in the food industry. The mechanical properties of alginate can be enhanced by crosslinking with Ca2+ ions, present in hydroxyapatite, for example, and by the introduction of reinforced phases. The main objective of this study was to investigate the effect of adding two-dimensional graphite oxide nanoflakes on the adhesion strength and electrochemical corrosion resistance of electrophoretically deposited biodegradable sodium alginate/hydroxyapatite coatings on titanium and Ti-13Nb-13Zr titanium alloy substrates. It was found that the coatings adhered well to the oxide layer covering the substrates. The adhesion strength of the coatings depended on the surface chemistry of substrates and the graphite oxide mass in the suspension used for deposition. Excellent adhesion strength was achieved by the chemical treatment of titanium and by adjusting the chemical composition (graphite oxide content) of the suspension. The addition of graphite oxide flakes improved the corrosion resistance of the hydroxyapatite/sodium alginate coatings in a chloride environment. The results of this study are relevant to enhance the corrosion resistance of metallic materials in aggressive environments to be utilized for biomedical engineering applications or in the food industry. Acknowledgments. This work was supported by the National Science Centre Poland (decision no DEC-2018/31/G/ST5/00429).