Corrosion inhibition of iron in 1 M HCl by some gemini surfactants in the series of alkanediyl-α,ω-bis-(dimethyl tetradecyl ammonium bromide)

Three new gemini surfactants in the series of alkanediyl-alpha,omega-bis-(dimethylalkyl ammonium bromide) were synthesised and tested as corrosion inhibitors of iron in hydrochloric acid medium using gravimetric, electrochemical polarisation and electrochemical impedance spectroscopy (EIS) measurements. Results obtained show that the surfactants studied are good cathodic inhibitors and act on the cathodic hydrogen reaction without modifying its mechanism. EIS results show that the changes in the impedance parameters (R-T and C-di) with concentration of surfactants studied is indicative of the adsorption of molecules of surfactant leading to the formation of a protective layer on the surface of iron. The effect of the temperature on the iron corrosion in both 1 M HCl and 1 M HCl with addition of various concentrations of 1,2-ethane bis-(dimethyl tetradecyl ammonium bromide) in the range of temperature 20-60degreesC was studied. The associated apparent activation corrosion energy has been determined. (C) 2001 Elsevier Science B.V. All rights reserved.