Inhibition and Adsorption impact of Leave Extracts of Cnidoscolus Aconitifolius on Corrosion of Aluminium Sheet in 1 M Hcl Medium

Abstract

Corrosion inhibition in the presence of alokaloid and non alkaloid extracts of Cnidoscolus aconitifolius in 1M HCl was studied using the weight loss and hydrogen evolution techniques at 303, 313 and 333 K. The results obtained revealed that the inhibition efficiency decreased with increase in temperature. Inhibition occurred through adsorption of the alokaloid and non alkaloid extracts molecules on the metal surface. The apparent activation energies, enthalpies and entropies of the dissolution process and the free energies and enthalpies for the adsorption process were determined and discussed. The fundamental thermodynamic functions were used to evaluate important inhibitive properties of Cnidoscolus aconitifolius.

Keywords: Activation energy; Gibb’s Free Energy; Langmuir adsorption; Cnidoscolus aconitifolius; Aluminium sheet.