Corrosion inhibition of aluminum by 1,1(lauryl amido)propyl ammonium chloride in HCl solution

The corrosion inhibition characteristics of I,1(lauryl amido)propyl ammonium chloride, as a cationic surfactant (CS), on aluminum in HCl solution have been studied in the temperature range 10-60 degreesC by means of weight loss, potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) techniques. Results obtained show that the inhibition occurs through adsorption of the surfactant on the metal surface without modifying the mechanism of corrosion process. The surfactant acts predominately as anodic inhibitor. The inhibition efficiency increases with an increase in the surfactant concentration, but decreases with an increase in temperature. Maximum inhibition is observed around its critical micelle concentration (CMC). Frumkin isotherm fits well the experimental data. Thermodynamic functions for both dissolution and adsorption processes were determined. Results obtained from the three methods are in good agreement. (C) 2001 Published by Elsevier Science B.V.