Corrosion inhibition performance of silver nanoparticles embedded-gloss paint on carbon steel and aluminium substrates in 2.0 M H2SO4 solution

Abstract

Corrosion control of metals in aggressive environments has attracted a lot of attention due to its associated economic losses. However, most corrosion control techniques have not satisfactorily minimized these losses. This study examined the inhibition effects of silver nanoparticles (AgNPs) incorporated in gloss paint on corrosion of carbon steel and aluminium in 2.0 M H2SO4 solution. The AgNPs were biosynthesized via green chemistry and characterized using Fourier Transform Infrared, UV-Vis spectrometer, and Transmission Electron Microscope. Samples of carbon steel and aluminium were uniformly coated with a thin layer of gloss paint mixed with AgNPs solution at five different concentrations of 0, 5, 10, 15, and 20 µg/ml. The inhibition efficiency of the AgNPs modified paint was conducted via gravimetric, gasometric, and potentiodynamic polarization analyses. Results of the gravimetric analysis revealed an increased weight loss with an increased period of exposure and decreased concentration of AgNPs in the paint. The corrosion rates for the mild steel and aluminium samples were 0.051 and 0.005 mmpy with inhibition efficiencies of 42% and 69%, respectively, when immersed in 20 µg/ml AgNPs-incorporated coating and exposed for 120 hours. Potentiodynamic polarization analysis revealed that the presence of AgNPs in the paint (as inhibitor) retarded the anodic dissolution by the formation of protective films on the mild steel and aluminium sample surfaces. The evolution of hydrogen gas from 20 µg/ml AgNPs-incorporated coating was significantly reduced by 81% and 14% for mild steel and aluminium, respectively when compared with the control samples at 200 minutes of exposure. These results revealed that the incorporation of AgNPs into the gloss paint matrix minimizes the degradation due to corrosion of the mild steel and aluminium samples.