Sol–gel hybrid films based on organosilane and montmorillonite for corrosion inhibition of AA2024

[Display omitted] •Addition of clay to silica-based sol–gel films protects aluminum from corrosion.•The protection of the hybrid depends on the concentration and type of clay.•Montmorillonite modified with quaternary ammonium salts provides the best protection.•Hybrid sol–gel matrixes doped with represents a robust system for corrosion. The present work reports the production of films on AA2024-T3 composed of vinyltrimethoxysilane (VTMS)/tetraethylorthosilicate (TEOS) with incorporation of montmorillonite (sodium montmorillonite and montmorillonite modified with quaternary ammonium salt, abbreviated Na and 30B, respectively), generated by the sol–gel process. According to FT-IR analyses the incorporation of montmorillonite does not affect silica network. Electrochemical characterization was performed by electrochemical impedance spectroscopy measurement in 0.05molL−1 NaCl solution. Results indicate that montmorillonite incorporation improves the corrosion protection compared to the non-modified system. Scanning electron microscopy micrographs reveal that high concentrations of montmorillonite provide agglomerations on the metallic surface, which is in detriment of the anticorrosive performance. The VTMS/TEOS/30B films with the lowest concentration (22mgL−1) of embedded clay provide the highest corrosion protection.