Coating of carbon steel alloy with polyvinyl alcohol/Fe3O4 nanocomposite to increase its corrosion resistance in 3.5% NaCl environment

Corrosion of carbon steel in saline environments poses major economic and safety risks across industries like oil, gas, and automotive. This study developed a Fe 3 O 4 /polyvinyl alcohol (PVA) nanocomposite coating to improve carbon steel’s corrosion resistance in a 3.5% NaCl solution. The nanocomposite, synthesized via a simple dispersion method, was characterized using FT-IR, XRD, SEM, and EDXA. Electrochemical analyses, including Tafel polarization and EIS, revealed the coating’s effectiveness in enhancing anticorrosion performance. The optimal composition, comprising 30% Fe 3 O 4 and 70% PVA with a 5-minute coating time, reduced the corrosion current density from 28.98 µA/cm² (bare steel) to 9.87 µA cm². Charge transfer resistance improved from 480.7 Ω to 3127 Ω, corresponding to protection efficiencies of 84.6 ± 0.9% from EIS and 65.9% from Tafel data. Surface analysis indicated that the Fe 3 O 4 nanoparticles dispersed uniformly in the PVA matrix, forming a tortuous barrier against corrosive agents. The impressive results are attributed to the Fe 3 O 4 nanoparticles’ barrier properties synergizing with PVA’s film-forming ability. This study highlights the PVA/Fe 3 O 4 nanocomposite as an inexpensive, efficient solution for providing effective short-to-medium-term protection.