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Synthesis of imidazoline‐based dissymmetric bis‐quaternary ammonium gemini surfactant and its inhibition mechanism on Q235 steel in hydrochloric acid medium
Author(s) -
Zhang J.,
Gong X.L.,
Song W.W.,
Jiang B.,
Du M.
Publication year - 2012
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.201006051
Subject(s) - hydrochloric acid , chemistry , adsorption , dielectric spectroscopy , langmuir adsorption model , inorganic chemistry , electrochemistry , pulmonary surfactant , ammonium , imidazoline receptor , heteroatom , nuclear chemistry , organic chemistry , ring (chemistry) , medicine , biochemistry , electrode
An imidazoline‐based dissymmetric bis‐quaternary ammonium gemini surfactant has been synthesized. Its surface active properties at equilibrium in water at 25 °C were determined. The inhibitive effect of the compound on Q235 steel in 1 M hydrochloric solution was investigated by the weight‐loss method, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) analysis, and quantum chemical calculations. The results indicate that the compound has high surface properties and the inhibition efficiency (IE) increases with the increase in inhibitor concentration, which attain the maximum value around the CMC value. The imidazoline‐based dissymmetric bis‐quaternary ammonium acts as a mixed type inhibitor mainly inhibiting the cathodic processes and does not change the mechanism of either hydrogen evolution reaction or mild steel dissolution. The best IE is obtained at the immersion time of 144 h. The adsorption of the studied inhibitor on Q235 steel can be fitted to a Langmuir isotherm and the adsorption process is a spontaneous chemical adsorption. Quantum chemistry calculation results show that the imidazoline ring and heteroatoms of N, O, are the active sites of the inhibitors.