Cationic gemini surfactant as corrosion inhibitor for mild steel in 1 M HCl and synergistic effect of organic salt (sodium tosylate)

Synergistic result of cationic gemini surfactant (GS) 1,2-bis(N-hexadecyl-N,N-dimethylammonium) ethane dibromide (16-2-16) and organic salt (Sodium tosylate; NaTos) on mild steel corrosion in 1 M HCl solution at various temperatures (30, 40, 50 and 60 degrees C) has been examined using gravimetric, electrochemical and surface morphology measurement. Investigational result shows that the inhibition efficiency (eta) of 16-2-16 GS enhanced in the existence of a set quantity of NaTos. The synergism parameter (S-theta) values are larger than unity, representing large inhibition efficiency, generated via the accumulation of NaTos to 16-2-16 GS is owing to adsorption supportive. The electrochemical results revealed that the 16-2-16 GS in the absence and presence of NaTos act as mixed-type inhibitors. The inhibitor adsorption on the mild steel surface in 1 M HCl solution obeys Langmuir adsorption isotherm. Surface morphology was studied using scanning electron microscopy (SEM).