Abstract

RAGHAVENDRA, Narasimha  and  BHAT, Jathi Ishwara. Anti-corrosion Properties of Areca Palm Leaf Extract on Aluminium in 0.5 M HCl Environment. S.Afr.j.chem. (Online) [online]. 2018, vol.71, pp.30-38. ISSN 1996-840X.  http://dx.doi.org/10.17159/0379-4350/2018/v71a4.

The aluminium corrosion inhibition behaviour in the presence of Areca palm leaves (AL) extract in hydrochloric acid (0.5 M) medium was examined by chemical (mass loss), AC impedance spectroscopy, potentiodynamic polarization and surface (scanning electron microscopy) methods. Aluminium protection rates increased with an increase in the amount of AL extract to the 0.5 M HCl system and decreased with increasing in the contact time of aluminium metal and temperature of 0.5 M HCl solution. Arrhenius equation was applied in the determination of activation energy values. The other activation parameters such as activation entropy and enthalpy values were obtained from the transition state plot. The adsorption of AL extract species on the Al surface in 0.5 M HCl solution follows the Langmuir adsorption mechanism. Tafel curves reflect the mixed (both anodic and cath-odic) inhibition behaviour of green inhibitor (AL extract species) on electrode surface (Al) in 0.5 M system. Impedance method indicates that the Al dissolution in hydrochloric acid environment was fully hindered by charge transfer process. The Al surface morphology was examined by applying scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques.

Keywords : Aluminium; Areca palm leaves; weight loss; Arrhenius equation; Langmuir adsorption.

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