Comparative Studies of Caladium Tricolor Stem and Leaf Biomass Extract as Corrosion Inhibitor for Mild Steel in Acidic Media

Abstract

This study presents a comparative investigation into the corrosion inhibiting properties of extracts derived from the stem and leaves of Caladium tricolor (wild cocoyam) in acidic media. The primary objective was to evaluate and compare the efficacy of these plant parts in mitigating metal corrosion, offering a potential green alternative to conventional synthetic inhibitors. The extracts were obtained through the solvent extraction process, and their performance was tested in two acidic environments: 0.5 M H₂SO₄ and 0.5 M HCl. The gravimetric method was employed, providing a direct measure of metal degradation over time. The results obtained demonstrate that both Caladium tricolor stem extract (CSE) and leaves extract (CLE) possess significant corrosion inhibiting properties in the tested media. The findings indicate a clear dependency of inhibition efficiency on both the concentration of the extract and the duration of exposure. Specifically, the inhibition efficiency for CSE ranged impressively from 50% to 99% across concentrations varying from 5 ml to 20 ml in both acidic solutions. Conversely, the CLE exhibited an efficiency range of 27.63% to 94.55% under the same concentration gradient. The stem extract (CSE) achieved its maximum inhibition efficiency of 98.92% at the highest tested concentration of 20 ml after 24 hours of immersion in 0.5 M H₂SO₄. In contrast, the leaves extract (CLE) attained its highest efficiency of 94.55% also at a 20 ml concentration, but required a longer immersion period of 72 hours and achieved this peak in 0.5 M HCl. These comparative results suggest that while both extracts are effective, the stem extract may offer superior and faster protection in a sulfuric acid environment.