AJCE_Vol 01 N 01

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Browsing AJCE_Vol 01 N 01 by Author "Husaini, Musa"

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    Corrosion inhibition of aluminium in phosphoric acid solution using glutaraldehyde as inhibitor
    (جامعة الوادي - university of el oued, 2020-08-15) Husaini, Musa; unusa, Umar; Ibrahim, Hussaina Aminu; Usman, Bishir; Ibrahim, Muhammad Bashir
    The effect of glutaraldehyde as corrosion inhibitor for aluminum in phosphoric acid solution was studied by using weight loss method and characterized by fourier transform infrared spectroscopic and scanning electron microscopic analysis. The inhibition efficiency increases with increase in inhibitor concentration and decreases with increase in temperature while the corrosion rates increases with rise in temperature and decreases with increase in inhibitor concentration. The value of activation energy (ΔEa) was found to be 32.61 kJ/mol in uninhibited acid solution and increased to 47.33 kJ/mol in the presence of 0.1 M inhibitor concentration. The positive values of the enthalpy of activation (ΔHa) suggest an endothermic nature of the reaction and negative values of activation entropy (ΔSa) shows that the activation complexes in the rate determining step represent an association rather than dissociation. The values of free energies of adsorption were all negative which indicate spontaneity of the process. The phenomenon of physical adsorption is proposed from the values of activation energy and free energy of adsorption. The results also shows that the adsorption of inhibitor molecules on the surface of aluminum is accord with Langmuir adsorption isotherm as to the values of correlation coefficient (R2) obtained were very close to unity. The result of the SEM analysis in the presence of inhibitor shows how the aluminium surface was protected against the aggressive effect of the acid. The new functional group in the FTIR analysis of the corrosion product is an indication of thin layer formation on the aluminium surface.
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    Organic compound as inhibitor for corrosion of aluminum in sulphuric acid solution
    (جامعة الوادي - university of el oued, 2020-10-17) Husaini, Musa
    The corrosion behavior of aluminum in H2SO4 solution was investigated by weight loss method in absence and presence of organic compound (glutaraldehyde) as inhibitor. Inhibition efficiency (I.E) was found to increase with increasing inhibitor concentration from 0.02 to 0.10 M and decrease as temperature increased. The activation energy value was 36.91 kJ/mol in uninhibited acid solution which increased to 61.80 kJ/mol in the presence of the inhibitor. The values of activation energy were found to increase with increase in inhibitor concentration due to the adsorption of more inhibitor molecules on the metal surface. The positive and negative values of enthalpy and entropy signified the endothermic adsorption process and formation of an ordered system. The negative value and low values of Gibbs’s free energy of adsorption indicate the spontaneous and physical adsorption mechanism of the adsorption process. The adsorption of inhibitor on the metal surface was found to accord with Langmuir adsorption isotherm. Fourier transform infrared spectroscopic analysis, scanning electron microscopic analysis, surface and functional group characterization supported the inhibitive effect of the glutaraldehyde at the metal surface