Adhesion aspects of hydrophobic silane zeolite coatings for corrosion protection of aluminium substrate

The adhesive properties of an anti-corrosion silane-zeolite coatings on aluminium substrates have been evaluated in this work. The coated samples were obtained by dip-coating sol-gel solution. Four different composite coatings at increasing zeolite amount (60-90 wt% of zeolite) have been investigated. The composite coatings evidenced a high hydrophobic behaviour (contact angle between 125°and 140°) and good adhesive properties with the aluminium substrate. The best results were obtained at low concentrations of zeolite. A structural model of the composite coating able to interpret phenomenologically the performances of this new protective coating has been proposed.