Advanced anti-corrosion coatings based on nanostructured organic layers

The corrosion protection performance of new organic coatings can be remarkably improved by the addition of nanoparticles or by the formation in-situ of nanoparticles. In these case we can speak about nano-structured organic coatings [1-7].Nanoparticles can modify the barrier properties of the organic layer through different mechanisms, in all the cases modifying in deep the structure of the layer.Many attempts has been done in the last years in order to better understand the role of nanoparticles in order to explore this technology for practical anti-corrosion application.In this work two examples, using different organic coatings systems and metal substrates, will be presented:· The properties of UV curable coatings were improved modifying the polymeric matrix adding properly functionalized silica inorganic nanoparticles. Mild steel sheets were used as substrate. We found that it is possible to use such UV curable water-based formulations also as matrices for the preparation of nanocomposites in which the filler is generated in situ The addition of a coupling agent between the organic and inorganic phase on the final properties of the nanocomposite has been studied.· The corrosion protection properties offered to galvanized steel and aluminum by an aqueous based silane layer are studied after incorporation of different amounts of sodium montmorillonite nanoclays (Na MMT). Moreover, inhibitive metallic cations can be incorporated in the nanoclays by ion exchange, providing a way to prepare cheap corrosion inhibitors nanoreservoirs offering self-healing properties.The corrosion protection properties were evaluated by electrochemical impedance spectroscopy (EIS) in aerated sodium chloride solution in combination with chemical surface analysis and electron microscopy observations.