Bronze preservation by using composite hydrogel coating-loaded corrosion inhibitors

Abstract Bronze has been used for various applications since ancient times, and therefore, its preservation is critical. However, preserving bronze is challenging. The traditional inhibitor sealing method is limited by its toxicity and sealing effects. In this study, a benzotriazole (BTA) inhibitor loaded with a composite hydrogel of sodium alginate and cyclic-peptide-grafted β-cyclodextrin was prepared. The chemical structure of the components of the composite hydrogel coating was characterized through Fourier-transform infrared spectroscopy. The microstructure of the coating on bronzeware was characterized through scanning electronic microscopy. The thermal analysis of the composite hydrogel coating confirmed that BTA was introduced successfully into the composite hydrogel, and the coating exhibited the liquid crystalline property because of the mesogenic unit—cyclic peptide. Electrochemical impedance spectroscopy revealed that the modified β-cyclodextrin-loaded benzotriazole considerably improved the corrosion resistance. In a certain range, the higher was the BTA-loaded Cyc-g-β-CD ratio, the stronger was the protective effect of the gel coating. In conclusion, corrosion inhibitors can considerably improve the corrosion resistance of gel coatings.