Corrosion performance of epoxy coatings containing silane treated ZrO2 nanoparticles on mild steel in 3.5% NaCl solution

Clear epoxy coatings were modified by adding various levels of ZrO2 nanoparticles. In order to achieve proper dispersion of nanoparticles in the epoxy-based coating and making possible chemical interactions between nanoparticles and polymeric coating, the surface of the nanoparticles was treated with amino propyl trimethoxy silane (APS). Corrosion performance of mild steel coated specimens was investigated employing EIS, electrochemical noise (ECN) techniques and salt spray test. Coatings with 2–3 wt% ZrO2 nanoparticles possessed the best corrosion performance among the coating specimens. Possible chemical interactions between polymeric matrix and treated nanoparticles in nanocomposites cause high barrier properties and ionic resistances.

Research highlights
► This work explains an efficient approach to improve corrosion performance of an epoxy-based coating with employing silane coupling agent treated ZrO2 nanoparticles.
► Corrosion performance of zirconia nanocomposites coated on mild steel specimens was investigated utilizing EIS and electrochemical noise (ECN) techniques.
► EIS and ECN results revealed, 2 or 3 wt% additions of ZrO2 nanoparticles significantly improved the corrosion resistance of epoxy coating via increasing barrier properties and ionic resistances of the coatings.
► The experimental results showed a good correlation between EIS and ECN findings.