Title : Ferrocene modified graphite epoxy coatings for corrosion protection of mild steel
Abstract:
Ferrocene (FC) derivatives have been widely investigated as corrosion inhibitors for mild steel (MS) in aqueous media, however, their use as functional additives in protective coating systems has received limited attention. In this work, pristine FC is fortified into a graphite epoxy coating (GEC) as an anticorrosive additive to improve the corrosion resistance of MS. FC was introduced at different loadings (0–16 wt%) into the GEC using an acetone/chloroform (20:80, wt/wt) azeotropic mixture as the processing medium. Successful incorporation and uniform dispersion of FC were confirmed through spectroscopic and microscopic techniques, including LIBS, XRD, Raman, FTIR, and EDS analyses. Electrochemical impedance spectroscopy revealed a maximum corrosion protection efficiency of 99.78% for the coating containing 16 wt% FC after 120 h of immersion in 3.5 wt% aqueous NaCl, in agreement with Tafel polarization results (99.07%). In addition, the FC-modified coatings exhibited a significantly reduced corrosion rate (0.26 μm y⁻¹), stable wettability with 99.9% contact angle retention, and minimal weight loss (0.71%) following salt-spray exposure at 95% relative humidity for 10 days. These improvements are attributed to a diffusion-controlled redox process, in which FC confined within the graphitic domains modulates charge transport and restricts electrolyte ingress. The findings demonstrate that pristine FC can serve as an effective additive in epoxy-based protective coatings for enhancing the corrosion resistance of MS under aggressive environmental conditions.
