The corrosion inhibition of carbon steel was studied by using an amido-imidazoline derivative and halide ions as an additive in CO2-saturated 3% NaCl solution with electrochemical techniques. The corrosion rate of the steel decreased with increase in the studied inhibitor concentration, while the inhibition efficiency increased and synergistically enhanced on addition of iodide ions. The values of synergism parameter found to be greater than unity. The experimental results revealed that the presence of iodide ions in the solution stabilized the adsorption of imidazoline molecules on the steel surface thereby improving the inhibition efficiency of the inhibitor. Furthermore, the adsorption of amido-imidazoline on the steel surface followed the Langmuir adsorption isotherm and it was chemically adsorbed on the surface of steel. The synergistic effect of iodide ions and amido-imidazoline was due to co-adsorption of iodide ions and amido-imidazoline molecules which was synergistic in nature.

Subject
Acid inhibitors, Steel surfaces, Ions, Synergistic effect, Adsorption, Polarization curves, Sodium chloride solution, Chemical inhibition, Inhibition efficiency, Corrosion inhibitors, Steel, Cathodic inhibitors, Anodic inhibitors
Keywords:
Amido-imidazoline, Synergism, Iodide ions, CO2 corrosion, Langmuir isotherm, EIS, Polarization
© 2012 Association for Materials Protection and Performance (AMPP). All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
2012
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.