Experimental and theoretical (DFT & MC) studies for the adsorption of the synthesized Gemini cationic surfactant based on hydrazide moiety as X-65 steel acid corrosion inhibitor

We synthesized new cationic Gemini surfactant (GI-surfactant) namely; N,N '-((ethane-1,2-diylbis(oxy))bis(2oxoethane-2,1-diyl))bis(N,N-dimethyl-4-((E)-(2-((E)-octadec-9-enoyl)hydrazineylidene)methyl)benzenaminium) dichloride and elucidated its chemical structure using different spectroscopic techniques. Polarization curves suggest that the inhibitor being studied is acting as a mixed-type. The higher concentration, the higher inhibition efficiency reaching 94% at 1 x 10(-4)M but it decreases to 64% with raising the temperature to 65 degrees C. Enrichment of GI-surfactant with the centers of high electron density increases the charge transfer resistance (R-ct) of X-65 steel and drops the corrosion rate. Adsorption phenomena was the reason for the inhibition action of the under studied GI-surfactant and followed Freundlich isotherm model. Adsorption affinity of GI-surfactant over X-65 steel was verified via Monte Carlo (MC) simulation and surface morphology study. X-ray diffraction (XRD) analysis indicates the reduction in metal oxides formation after GI-surfactant addition. This supports the inhibitory effect of the tested GI-surfactant.

Automated summary

The study reported the synthesis of a new cationic Gemini surfactant (GI-surfactant) and its inhibitory effect on X-65 steel corrosion. Results showed that GI-surfactant had a mixed-type inhibitory effect, with higher efficiency at higher concentrations but decreased at elevated temperatures. Adsorption phenomena and the Freundlich isotherm model were found to be responsible for the inhibition action of GI-surfactant, which was supported by Monte Carlo simulation and X-ray diffraction analysis.