Corrosion inhibition of aluminium in alkaline solution using aqueous extract of Tridax procumbens leaves

摘要

The influence of aqueous extract of Tridax procumbens leaves (TPL) on corrosion of aluminium in 0.5 NaOH solution was studied using chemical and electrochemical techniques. It was found that the inhibition efficiency increased with the increase of Tridax procumbens extract upto 900 ppm. Beyond this concentration there is no improvement in the inhibition efficiency. Electrochemical measurements revealed that TPL extract acts as a mixed type inhibitor. Adsorption of TPL extract was found to follow Langmuir adsorption isotherm. The results obtained from chemical and electrochemical measurements are in reasonably good agreement. The protective film formed on the surface of aluminium by the adsorption of water-soluble chemical constituents of TPL extract was confirmed using scanning electron microscopy studies.