A study of anti-corrosion behavior of octadecylamine-treated iron samples

The optimum conditions for the anti-corrosion behavior of the octadecylamin e (ODA)-treated iron samples in electrolytes containing chloride, sulfate a nd carbonates ions were established using electrochemical impedance spectro scopy. The best protective ODA film was formed on the surface after the iro n samples were treated in steam at 220 degrees C in an autoclave for 1 h, u sing a solution ODA concentration of 25 mg/L. The photoelectrochemical resu lts revealed that ODA modified the physical structure of the iron oxide lay er. From the Auger electron spectroscopic analysis, it is believed that the surface layers of the ODA-treated samples consisted of one of the followin g structures: at ODA concentrations < 20 mg/L: iron/iron oxide/mixed ODA-ir on oxides; at ODA concentrations greater than or equal to 20 mg/L: iron/iro n oxide/mixed ODA-iron oxides/ODA. (C) 2000 Published by Elsevier Science B .V. All rights reserved.