In Situ Synthesis and Long-Term Corrosion Inhibition Performance of GO-PANI@ZP Composite

Abstract

This study successfully synthesized a graphene oxide-polyaniline@zinc phosphate (GO-PANI@ZP) composite through in situ polymerization and stepwise ion introduction. Using graphene oxide (GO) as the substrate, the sequential deposition of polyaniline (PANI) and zinc phosphate (ZP) mitigates the hydrophilicity and reduces interlayer agglomeration. The lamellar structure provides a physical barrier that extends corrosive media penetration pathways. PANI contributes redox reversibility to dynamically regulate charge transfer, facilitating the formation of an electrochemical protective layer. Protonated PANI responds to corrosion reactions and releases corrosion inhibitors. Additionally, the composite exhibits a microcapacitor effect, establishing a stable charge barrier at the coating-substrate interface that impedes corrosive species penetration. After 168 h of immersion in 3.5 wt % NaCl solution, the composite coating demonstrated a total impedance value 4.56 times that of epoxy resin, revealing exceptional corrosion resistance. This work provides a novel design strategy for developing organic–inorganic composite anticorrosion materials.