Quantum chemical calculations, synthesis and corrosion inhibition efficiency of ethoxylated-[2-(2-{2-[2-(2-benzenesulfonylamino-ethylamino)-ethylamino]-ethylamino}-ethylamino)-ethyl]-4-alkyl-benzenesulfonamide on API X65 steel surface under H2S environment

• Published in: Journal of molecular liquids Vol. 212; pp. 360 - 371
• Main Authors: Migahed, M.A., Al-Sabagh, A.M., Khamis, E.A., Zaki, E.G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2015
• Subjects: Carbon steel; Corrosion inhibition; EIS; H2S environment; Nonionic surfactants; Polarization; Quantum calculation; SEM; Polarization; H2S environment; Quantum calculation; Nonionic surfactants; Carbon steel; SEM; Corrosion inhibition; EIS
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2015.09.032

The effect of four novel nonionic surfactants based on sulphonamide as corrosion inhibitors for X-65 type carbon steel in oil well formation water under H2S environment was investigated by electrochemical measurements. The obtained results revealed that synthesized surfactants perform as acceptable corrosion inhibitors. Scanning electron microscopy (SEM) was used to examine surface morphology in the absence and presence of inhibitors molecules. It was found that the inhibition efficiency depends on the ethylene oxide content in the molecule. The quantum chemical calculations were carried out to study the molecular geometry and electronic structure of obtained derivatives. The energy gap between the highest occupied molecular orbital and lowest unoccupied molecular orbital has been calculated using the theoretical computations to reflect the chemical reactivity and kinetic stability of compounds. •Four novel nonionic surfactants based on sulphonamide were synthesized.•Inhibition efficiency depends on the number of ethylene oxide units in the molecule.•Electrochemical techniques were used to evaluate as corrosion inhibitors.•SEM and EDX techniques were used to study the nature of protective film.•Quantum was applied to the synthesized surfactants to predict Their efficiencies.