Effect of synthesized NiFe2O4-silica nanocomposite on the performance of an ecofriendly silane sol-gel coating

In this research, nickel ferrite nanoparticles dispersed in a silica matrix (NiFe2O4-SiO2) were prepared by sol-gel method. In addition to characterizing the particles using XRD and FTIR, TEM observations indicated that the silica matrix network provides an ideal nucleation environment to uniformly disperse NiFe2O4 nanoparticles and thus to confine them to aggregate. The synthesized particles were then incorporated into an ecofriendly silane sol-gel coating applied on mild steel. The data extracted from electrochemical impedance spectroscopy indicated superior corrosion resistance of mild steel covered by the silane coating with 1000 ppm of NiFe2O4-SiO2 particles compared to the substrate coated with neat silane. As shown by FESEM and AFM, a uniform, smooth and crack-free coating was formed in the presence of NiFe2O4-silica nanocomposite. According to FTIR and water contact angle measurements, the superiority of the nanoparticles inserted coating was suggested to be associated with stronger network reticulation providing more efficient barrier between the substrate and the sodium chloride solution.