Synergistic Effect Of Water Soluble Chitin And Iodide Ion On The Corrosion Inhibition Of Mild Steel in Acid Medium

¹Department of Chemistry, The Gandhigram Rural Institute – Deemed University, Gandhigram, Tamil Nadu, 624 302, India

²Department of Science and Humanities, Women’s Polytechnic College, Lawspet, Puducherry, 605008, India

Adv. Mater. Lett., 2016, 7 (7), pp 587-592

DOI: 10.5185/amlett.2016.6318

Publication Date (Web): Jun 12, 2016

Copyright © IAAM-VBRI Press

E-mail: sairam_adithya@yahoo.com

Abstract

The inhibition performance of water soluble chitin (WSC) and its synergistic inhibition with potassium iodide (KI) in 1 M HCl was studied using gravimetric and electrochemical measurements. From gravimetric measurement it is inferred that there is an increase in inhibition efficiency with the increased addition of inhibitor and it further stepped up to a higher value in the presence of 0.1 % KI. Polarization studies revealed that there is mixed mode of inhibition by WSC. Impedance study suggested the adsorption of the inhibitor at the interface between mild steel and acidic solution. The adsorption of inhibitor followed Frumkin isotherm. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) confirmed the co- adsorption of KI with WSC on the mild steel surface. Fourier Transform Infra-red (FTIR), Atomic Force Microscopy (AFM) and X- ray Diffraction (XRD) indicated the formation of protective film by the inhibitor on the surface of mild steel.

Keywords

Mild steel, chitin, acid corrosion, FTIR, AFM.