SYNTHESIS OF ORGANIC-INORGANIC HYBRID COATINGS FOR THE PROTECTION OF ALUMINUM SUBSTRATES

A silica-based organic-inorganic hybrid coating has been developed for corrosion protection of aluminum substrates by dip-coating technique. The hybrid sols were prepared by hydrolysis and condensation of trimethoxy(7-octen-1-yl)silane (TMOS) and tetraethyl orthosilicate (TEOS) in the presence of acetic acid. Structural characterization of the hybrid coatings was performed using powder X-ray diffraction analysis (PXRD). The morphology of the coating has been studied by scanning electron microscope (SEM). Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) tests have been performed, and the results showed that the silane coatings had high corrosion resistance. The heat treatment of the coatings at various temperatures have been investigated, and the results show that 130(circle)C is an optimized temperature. The results expose that the hybrid coating enhanced the corrosion protection of aluminum in aqueous 3.5% NaCl solution.