Investigation of smart graphene oxide multilayer nanocoating for improved steel structural protection in natural seawater.

The GO-AMTT/TiS₂ nanofiller was developed by combining surface-modified titanium disulphide (TiS₂) with graphene oxide (GO) and 2-amino-5-methylthio-1H-1,2,4-triazole (AMTT), and it was subsequently incorporated into the epoxy resin (EP) to produce EP-GO-AMTT/TiS₂ nanocomposite. Using electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM), the performance of epoxy coating on mild steel as a barrier against different concentrations of GO-AMTT/TiS₂ in naturally occurring seawater was evaluated. It was found that that epoxy coating with 0.6 weight percent of GO-AMTT/TiS₂ nanoparticles exhibited the highest resistance after exposed to seawater for 1 h. The limiting oxygen index test and thermogravimetric analysis revealed that the GO/AMTT-TiS₂ significantly improved the flame retardancy properties of the epoxy coating. The peak heat release rate and total heat release values for the EP-GO/AMTT-TiS₂ significantly decreased by 74% and 66%, respectively, as compared to pure EP, showing that the material is more flame retardant. The EIS experiments showed that the EP-GO/AMTT-TiS₂ nanocomposite had increased coating resilience even after 960 h of submersion in seawater. According to SECM investigations, a small amount of ferrous ions was released at the scribe area of the EP-GO/AMTT-TiS₂ coating. This is because the coated substrate is more resistant to anodic dissipation than the uncoated substrate. The developed EP-GO/AMTT-TiS₂ coating has higher protective and hydrophobic (WCA: 157°) characteristics. The epoxy matrix's adhesive properties were enhanced by the addition of GO/AMTT-TiS₂. Therefore, an EP-GO/AMTT-TiS₂ nanocomposite may be employed in an industrial coating. [ABSTRACT FROM AUTHOR]