Maduabuchi A. Chidiebere

Experimental and theoretical assessment of the inhibiting action of Aspilia africana extract on corrosion aluminium alloy AA3003 in hydrochloric acid

The adsorption of Aspilia africana extract and subsequent corrosion inhibition of aluminium alloy AA3003 in hydrochloric acid solutions have been investigated using gravimetric and electrochemical techniques. Inhibition efficiency increased with extract concentration and temperature rise. Polarization studies revealed that the extract essentially inhibited the cathodic reaction. An adsorption mechanism involving physisorption and chemisorption of extract constituents at low and high temperatures, respectively, has been proposed from the trend of adsorption-free energies. Quantum chemical computations and molecular dynamics simulations described the individual contributions of some extract constituents to the observed inhibiting effect.

The effect of microstructure and elemental content on corrosion and corrosion inhibition of mild steel in a 0.5 M H2SO4 environment

The influence of composition and surface microstructure on the corrosion behavior of low carbon steel specimens from Nigeria (NCS) and China (CCS) in a 0.5 M H2SO4 environment has been investigated using electrochemical techniques and surface probe techniques. The corrosion inhibition performance of Chrysophyllum albidum extract (CA) and synergistic iodide additives (KI) were assessed as well. The obtained results reveal that NCS was more susceptible to corrosion in uninhibited 0.5 M H2SO4 solution than CCS, which presented a more positive surface charge. CA inhibited the corrosion of both specimens, yielding maximum inhibition efficiencies of 89.6% and 48.5% for NCS and CCS, respectively, which were further increased to 93.9% and 98.9% on introduction of iodide ions. The corrosion and corrosion inhibition behavior of the carbon steel specimens were influenced by the metal composition and microstructure.