Experimental and theoretical insights into synthesized Gemini corrosion inhibitor for X65-steel in 1M HCl

Abstract

Three Gemini cationic surfactants (GI-surfactants) of different hydrophobic chain lengths based on di-imine compound, abbreviated as GI-6, GI-12 and GI-14, were synthesized and characterized using FT-IR and 1 HNMR. The surface-active parameters calculated in acidic media were discussed. The inhibition performance of GI-surfactants for X65-steel corrosion was assessed by weight loss and electrochemical techniques in 1M HCl and was accompanied by surface analysis and theoretical studies. The resistance of X65-steel was enhanced to nearly ⁓764 ohm.cm 2 after adding 1x10 -3 M of GI-14. This inferred a protective film formation on the X65-steel surface via adsorption phenomena that followed the Langmuir isotherm. The GIsurfactants' inhibition efficiency exceeded 95% at room temperature and 93 % at 328 K owing to the electron-rich centers' presence in their chemical structures. The relation between the prepared GI-surfactants molecular structures and their corrosion inhibition performance was studied theoretically based on DFT and MCs methods. The safeguard effect of GI-surfactants was confirmed by SEM and EDX. The comparison study between the GI-surfactants' performance and the previously reported compounds confirmed their high potential applications as corrosion inhibitors.

Raman and Infrared Spectral Analysis, Normal Coordinate Analysis, DFT calculations of Novel Schiff Base Containing di-imine moieties.

“…The Schiff-B was prepared using round flask fitted with water-cooled condenser. The 4-(Dimethylamino) benzaldehyde and 1,4-Diaminobutane (2:1 molar ratio in 25 mL of EtOH) were refluxed in a heating mantel with three droplets of HCl for 7h at 80C with continuous stirring to yield ((N 1 Z, N 4 E)-N 1 , N 4 -bis (4 (dimethyl amino) benzylidene) butane 1,4-diamine), as shown in Scheme 1 [29]. Adding HCl were kept to a minimum to avoid the protonation of imine nitrogen atom(s).…”