Self-healing corrosion protection by nanostructure sol-gel impregnated with propargyl alcohol

Zirconia based nanostructured hybrid sol-gel coating, impregnated with propargyl alcohol (PA) to hinder corrosion of mild steel was studied. Zirconia nano-particles (TPOZ) contained sol-gel was synthesized using 3-glycidoxypropyltrimethoxysilane (GPTMS) as precursor and subsequently optimized for internal cohesion as well as adhesion to the mild steel substrate to assess the consequent effect on suppression of corrosion damage in 0.5 M NaCl solution. Electrochemical Impedance Spectroscopy (EIS) and Scanning Electron Microscopy (SEM) results demonstrated the effect of coating integrity on impeding corrosion. Experiments on mild steel specimens coated with hybrid sol-gel films following mechanical polishing render superior corrosion resistance to mild steel in contrast to those undergoing electrochemical polishing with marked lower surface roughness. Results also proved of beneficial effect of low and exact concentration of PA on sol-gel coat's barrier properties evident from diminished corrosion current and other electrochemical indicators. (C) 2009 Elsevier Ltd. All rights reserved.