CoAl2O4/TiO2 nano composite as an anti-corrosion pigment

It is well-known that corrosion the incorporation of inorganic pigments is efficient and economical way to improving the corrosion protection performance of the epoxy coating. In this study a series of eco-friendly anti corrosive nano composite pigments was synthesized by precipitating of different weight percentages of CoAl2O4 on the surface of TiO2 nanoparticles followed by a calcination process. The bright blue colored pigment was obtained using only 10 wt% of CoAl2O4 to TiO2. Coating of epoxy and nano composite doped coating was applied on mild steel substrate for corrosion analysis. The effect of the weight % of CoAl2O4 on anti-corrosive properties of the epoxy/nano composite coatings was investigated by electrochemical impedance spectroscopy in 3.5% NaCl solution. The composite pigment comprising about 70 wt% of TiO2 covered with a thin layer of CoAl2O4 showed the best anti corrosion properties. The corrosion protection of 99.99% was obtained from Tafel plot.