Investigation of multifunctional nanocomposite coatings containing GO and NbC for the protection of steel structures in harsh environment

Abstract

Graphene oxide (GO) was combined with functionalized niobium carbide (NbC) by 2-amino-3-ethylbenzenethiol (AEBT), and the resulting GO/AEBT-NbC nanofiller was added to the polyurethane matrix (PU). The protective effectiveness of polyurethane coated steel was examined using electrochemical techniques in the presence of various concentrations of GO/AEBT-NbC in 3.5 % NaCl. For the application of coatings, PU-GO/AEBT-NbC nanocomposite was designed with outstanding physico-mechanical properties that show high levels of durability and corrosion resistance. It was shown that a weight ratio of 0.6 for GO-AEBT/NbC in the PU matrix produced the best coating performance. The resistance of the PU-GO/AEBT-NbC coating was discovered to be 81.5 times more than that of pure PU after being exposed for 1 h to the chloride environment. The EIS measurements showed that the PU-GO/AEBT-NbC nanocomposite exhibited increased coating resistance (12550 kΩ.cm2) even after 320 h of immersion in 3.5 % NaCl. Due to the increased resistance to anodic dissolution, SECM experiments showed that the least number of Fe2+ ions discharged (1.0 I/nA) at the scratch of the PU-GO/AEBT-NbC coating. The presence of NbC in the constituents of the rust helps to produce an excellent coating protection. The results show that the recently created PU-GO/AEBT-NbC composite has improved barrier and hydrophobic properties (WCA: 165°). The GO-AEBT/NbC additive enhanced the PU matrix's mechanical properties. The PU-GO/AEBT-NbC coating material is considered to be the best nanocomposite for industrial applications. Consequently, we were able to create a promising PU-GO/AEBT-NbC nanocomposite top coat for marine coating applications that has excellent thermal stability, superhydrophobicity, surface inertness against corrosion, cost effectiveness, and enhanced lifetime.