Datura Metal as a Potential Corrosion Inhibitor for Aluminium in 1M HCL solution

The corrosion inhibition of commercial Al in 1M HCl medium by Datura metel (DM) leaves extract was carried out using chemical and electrochemical techniques. Effect of temperature, immersion time and acid concentration were discussed. The inhibition efficiency increases with increase in concentration. The inhibition efficiencies were also evaluated using hydrogen evolution technique at 303K. Using potentiodynamic polarisation technique the extract proved that mixed type inhibitor. EIS showed that the charge transfer control s the corrosion process. These results revealed that Datura metel (DM) was an effective inhibitor and theinhibition efficiencies obtained from weight loss, hydrogen evolution measurements, potentiodynamic polarisatio n and ac impedance technique were in good agreement. Phytochemical analyses show that the leaves extract containing alkaloid and steroids. These are responsible for inhibition. The inhibitive action of the extract was discussed using Langmuir adsorption isotherm. Thermodynamic and kinetic parameters such as activation energy,free energy of adsorption, change in entropy and change in enthalpy were also calculated. The negative value of the free energy of adsorption indicates that the adsorption of inhibitor molecules was spontaneous. Phy sical adsorption proposed from activation parameters.