Enhancing epoxy coatings with spherical ZnO nanoparticles for improved hydrophobicity and corrosion resistance

This study explores the integration of spherical zinc oxide (ZnO) nanoparticles into epoxy (EP) coatings to enhance hydrophobicity and corrosion resistance. Through sol-gel synthesis, ZnO nanoparticles with a spherical morphology were successfully fabricated, as confirmed by UV-Vis spectroscopy, FT-IR, XRD, and SEM/EDX analyses. The spherical shape of ZnO facilitated dense packing within the epoxy matrix, significantly improving coating compactness and superhydrophobicity, evidenced by a contact angle of 101.5°, a 17.5% increase over pure epoxy. Electrochemical assessments revealed remarkable corrosion protection: the epoxy-ZnO (EPZ) coating reduced the corrosion rate to 0.00092 mm.y−1 after 5 days of immersion in 3.5% NaCl, outperforming pure epoxy (0.019 mm.y−1). Polarization resistance surged to 2.19 × 106 Ω·cm2, 25 times higher than epoxy alone, while coating resistance reached 3.62 × 105 Ω·cm2, demonstrating superior barrier properties. EDX analysis further highlighted ZnO’s protective role, showing a 46.74% reduction in Al2O3 corrosion products compared to unmodified epoxy. These findings underscore the potential of spherical ZnO nanoparticles to revolutionize protective coatings by combining enhanced hydrophobicity with robust electrochemical stability.