Outstanding anticorrosion and adsorption properties of 2-amino-6-methoxybenzothiazole on Q235 and X70 carbon steels: Effect of time, XPS, electrochemical and theoretical considerations

초록

The corrosion inhibitory properties of 2-amino-6-methoxybenzothiazole (2AMB) on Q235 and X70 steels in 0.25 M H2SO4 + 0.5 M NaCl solutions was investigated using combined experimental and theoretical approaches. The impedance data for the inhibited systems taken over lengthened immersion times revealed somewhat increasing film resistances with increasing immersion times which is related to the formation process of dense self-assemble monolayer (SAM) film on the steel surface causing a striking increase in inhibition efficiency over time. The polarization data showed that the 2AMB SAM-film remarkably lowered both the anodic and cathodic current densities. Following the protonation of 2AMB, the adsorption of the 2AMB species which obeyed the Langmuir adsorption isotherm involved a combination of physisorption and chemisorption processes. The interaction of 2AMB with the steels was confirmed by intensive XPS characterization, while the physical protective effect was revealed with scanning electron micrographs (SEM). Computational data complemented the experimental data in affording insights on the role of the electronic properties of 2AMB on its interaction and adsorption on steels. © 2020 Elsevier B.V.

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