Aloe vera L. as Green Corrosion Inhibitor for Mild Steel in 5.0 M Hydrochloric Acid Solution

摘要

The leaf gel of Aloe vera L. was examined for its anti-corrosion properties for mild steel in 5.0 M hydrochloric acid as corroding solution by using different techniques like weight loss, gasometric, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Aloe vera L. extract is selected for this study in view of its rich source of organic molecules. The percentage corrosion inhibition efficiency (PCIE) is found to increase with increase in concentration of Aloe vera L. i.e. from 0.1 to 4.0 g/L. Electrochemical experiments confirms that Aloe vera L. acts as a mixed-type green corrosion inhibitor. The activation parameters obtained from corrosion experiments showed that the inhibitor is adsorbed by both physisorption and chemisorption method. Scanning electron microscopy (SEM) and trinocular inverted metallurgical research microscopy study confirms the physisorption adsorption of Aloe vera L. molecules on the surface of mild steel. 97 % corrosion inhibition efficiency was shown by 4 g/L of Aloe vera L. in 5 M HC1 solution for mild steel.