The objective of the present study is to develop epoxy-based coating containing graphene nanoplatelets (0.25 (w/w)) coated with niobium at different concentrations (0.1, 0.5, 1, and 2% (w/w)) using magnetron sputtering technique for further use on an aluminum alloy panel (AA7075). Raman spectroscopy, wettability, impact, and corrosion resistance (ACET), electromagnetic shielding, and morphological analysis of the nanocomposites were performed. The hydrophobicity showed an increase of ∼27% for higher niobium concentrations (compared to the neat epoxy). Also, at higher niobium concentrations (1 and 2%), the electromagnetic shielding showed an attenuation peak at −8 dB for the frequency range 8–10 GHz (compared to a resonance peak of −6 dB at 10.2 G Hz for 0.5% Nb). The results showed that the incorporation of graphene nanoplatelets decorated with niobium proportionate an increase of 2 dB as electromagnetic barrier, which can be related to a conducted network formed by niobium on the surface of the coating via absorption mechanism magnetic properties. ACET showed an increase in the properties by higher niobium concentrations (1 and 2%), indicating an improvement in the shielding protection and corrosion resistance of the suggested composites. The other properties did not show any improvement of the properties.
Longhi et al. (Thu,) studied this question.