Quadruple-action coatings provided by doping epoxy with inhibitor laden clay nanotubes functionalized with layer-by-layer of cross-bridged chitosan and anionic polyelectrolytes

Abstract

The present study divulges the quadruple-protective-action including combined enhanced barrier, active feedback protection, self-repairing and anti-fouling properties of epoxy composite coatings reinforced with benzotriazole-laden clay nanotubes capped with ferric ion and wrapped with layer-by-layer (LBL) assembly of chitosan/polyacrylic acid (CTS-PAA-CTS-PAA) and chitosan/polymethacrylic acid (CTS-PMMA-CTS-PMMA) polyelectrolytes cross-bridged with (+D)-epichlorohydrin. UV–vis spectrophotometric technique reveals the pH-responsive release of the loaded benzotriazole, while scanning vibrating electrode technique (SVET), electrochemical impedance spectroscopy (EIS) and optical techniques reveal the combined active feedback corrosion suppression and self-repairing of impressed defects. Additionally, confocal laser scanning microscopy (CLSM) and SEM techniques reveal the anti-bacterial properties. The experimental results confirmed that the new composite coatings exhibited unprecedented quadruple-action protection.