Evaluation of Grewa Venusta (Wild Jute Tree) Extract as Corrosion Inhibitor for Mild Steel in Acidic Environment

• Autor(a) principal: Suleiman,I.Y.
• Data de Publicação: 2017
• Outros Autores: Salihu,Sani A., Emokpaire,O.S., Ogheneme,O.C., Shuaibu,Lasisi
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-19042017000300003
• topic: Adsorption isotherm; characterizations; GC-MS; SEM; halide ions

The feasibility of using extract of Grewa Venusta (wild jute tree) root as corrosion inhibitor with mild steel was investigated using gravimetric and electrochemical techniques in 1.0 M hydrochloric acid. The inhibitor’s concentration, temperature and time were varied in the range of 0-10% v/v at 2% v/v interval, 30 -75 oC at 15 oC interval and 1-6 hours at 1 hour interval. Characterizations of the extract were done by quantitative method (AAS) and Gas Chromatography-Mass Spectrometry (GC-MS). Scanning electron microscope (SEM) was used to analyze the surface morphology of the samples. The synergetic effect of the inhibitor was evaluated by addition of halide ions (KBr-, KCl-and KI-). The results showed that corrosion rate increased with an increase in temperature, and decreased with an increase in inhibitor’s concentration and time; maximum inhibition efficiency was 97.60% and 99.88% in the presence of KI- addition, and was assumed to occur via adsorption of the inhibitor molecules on the metal surface. The extract contains metallic elements such as calcium, magnesium, mono acetate (C5H10O4) and 4H-Pyrazole (C9H10F6N2S) that suppressed the anodic dissolution. The adsorption of the extract molecules on the mild steel surface obeys Langmuir adsorption isotherm. The results showed that the inhibitor acted as a mixed- type inhibitor.