Abstract
The counterion-coupled surfactant (RBOS-12) based on rice bran oil is synthesized, characterized, and evaluated as a new inhibitor for carbon steel corrosion. The inhibition, and synergistic effect performance of individual RBOS-12, and that is combined with chloride ions on the corrosion of carbon steel in a molar sulphuric acid medium at 30–60 ± 1 °C has been examined using open circuit potential-time, linear polarization resistance (LPR) corrosion rate, impedance spectroscopy (EIS), potentiodynamic polarization (PDP), surface topology (Field emission-scanning electron microscopy/Energy dispersive X-ray analysis (FE-SEM/EDS), X-ray diffraction (XRD) and UV–vis spectroscopic studies), density functional theory (DFT) and molecular dynamics (MD) simulations. Experimental findings exhibited that the inhibition capacity of individual RBOS-12 is 95.5% at the concentration of 1.0 × 10−3 M. Synergistic inhibition effect was observed between the RBOS-12 surfactant and the Cl- ion additives, with the maximum corrosion inhibition capacity as high as ~99.1% at 1 × 10–5 M RBOS-12 + 0.1 M Cl- ions. The individual RBOS-12 and RBOS-12/Cl− system get adsorbed onto the metal interface through mixed categories of adsorption mainly with the chemisorption. Meanwhile, the adsorption mode follows the Langmuir isotherm model. FE-SEM/EDS and XRD investigates approve the protective and adsorption capabilities of the individual RBOS-12 and RBOS-12/Cl− inhibitor systems. UV–vis spectroscopic analysis display that the additive interacts with metal in H2SO4 medium to form Fe-inhibitor complexes. DFT calculations and MD simulations further support the empirical outcomes. The findings exhibited that the prepared RBOS-12/Cl- system can be used as economic, eco-friendly, and efficient corrosion inhibitor with good anticorrosion properties for metals in acidic environments.
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•Novel counterion-coupled surfactant based on rice bran oil has been synthesized•The inhibition and synergistic effect performance of surfactant in a blend with chloride ions have been examined.•The findings exhibited that the protection capacity of the surfactant/chloride system reaching a maximum value of 99.1%•Theoretical approaches further support the experimental results