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New surfactants N ‐alkyl‐ N , N ‐dimethyl‐ N ‐(3‐thienylmethylene)ammonium bromides: Preparation and anticorrosion evaluation
Author(s) -
Chen Ziyu,
Xiaohui Jiang,
Cheng Zhengjun,
Liao Yunwen,
Pu Qiang,
Duan Ming
Publication year - 2019
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.201810632
Subject(s) - alkyl , electronegativity , chemistry , molecule , ammonium , electrochemistry , adsorption , dielectric spectroscopy , electron transfer , medicinal chemistry , inorganic chemistry , stereochemistry , organic chemistry , electrode
A new series of N ‐alkyl‐ N , N ‐dimethyl‐ N ‐(3‐thienylmethylene)ammonium bromides (designated as NTA‐ n , n = 8, 10, 12, 14, and 16) were synthesized. The electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization showed that NTA‐ n could protect availably X70 steel from attack of HCl with an inhibition efficiency of about 95%. And the inhibition ability follows the following sequence: NTA‐8 < NTA‐10 < NTA‐12 < NTA‐14 < NTA‐16, suggesting that prolonging alkyl chain may enhance the inhibition capacity of the molecules. Theoretical investigation backs up well the experiment results. The correlation of theoretical calculation with the experiment results illustrated clearly double logarithmic relations between the corrosion current and the computed quantum chemical parameters such as the highest occupied molecular orbital energy ( E HOMO ), energy gap (Δ E ), molecular volume (ν), electronegativity (χ), the total energy of iron crystal with the adsorbed inhibitor molecule ( E total ), the interaction energy of Fe (1 0 0) surface and inhibitor molecules ( E inhibitor ), while an equation resembling Hammet relation was existed between the corrosion currents and the fraction of electrons transfer (Δ N ). These linear correlations suggest the relation of the inhibitor structure with its inhibition activity: long alkyl chain and electron donating groups in NTA‐ n will enhance the corrosion efficiency.