Corrosion Inhibition of Mild Steel in Acidic Media by Citrus Microcarpa (Calamansi) Leaf Extract
Christine Bolo, Archie P. Amba, Geelyn Raeanne C. Rellin, Jayfe Anthony Abrea
Philippine Science High School, 6021, Argao, Cebu, Philippines.
Abstract: Corrosion inhibition is usually done through means of commercialized products such as paint. However, due to the desire in finding a close substitute, green inhibitors were made and tested through means of experimentation. The corrosion inhibition efficiency of Citrus microcarpa (Calamansi) leaf extract on mild steel in 1.0 M hydrochloric acid was investigated under ambient temperature. Different concentrations of the leaf extract were prepared (0.02, 0.04, 0.06, 0.08 g/mL) alongside with 1.0 M hydrochloric acid as the control solution. The mild steel samples were immersed in these solutions, monitored in a 192 – hour duration and the corrosion inhibition efficiencies were calculated using the mass loss method. The results showed significant inhibition efficiencies greater than 70% for all extract concentrations with respect to the control. The highest obtained inhibition efficiency was 97.40±0.218% at 0.08 g/mL extract concentration. This corrosion inhibition was implied to undergo chemisorption mechanism process with adsorption isotherm models that fit to both from Lanmguir and Freundlich (R^2 values > 0.99). The results also showed that the corrosion and its inhibition process fit best in zero – order kinetics where the residual mild steel mass is proportionate with time (R^2 values > 0.98). The Citrus microcarpa (Calamansi) leaf extract therefore serves as an effective corrosion inhibitor of mild steel in hydrochloric acid media.
Keywords: corrosion, mild steel, calamansi, weight loss.
Pages: 61 – 69 | Full PDF Paper