Examining the Inhibitive Effect of Alanine on Corrosion of Aluminium in Acidic Medium

The study examined how alanine inhibits corrosion of aluminium coupons in an acidic environment using a 0.5M HCl solution. The weight loss method was used for synthesis. Aluminium sheets with a purity of 98.98% were cut into rectangular coupons measuring 2cm x 4cm and were 1.0 mm thick. The total surface area of each coupon was 8 cm2, which was reduced by washing with absolute ethanol and drying in acetone. These rectangular coupons were fully immersed in the acid solution with different concentrations of the inhibitor for time intervals ranging from 30 minutes to 3 hours. The inhibitor at the optimal concentration reduced aluminium corrosion by about 14.6%, and the inhibition efficiency varied significantly with different alanine concentrations. The presence of heteroatoms in the inhibitor helped absorb onto the metal surface, displacing water molecules and creating a protective barrier. The findings indicated that alanine in 0.5M HCl has some inhibiting properties for lowering the corrosion rate of aluminium. However, the results also showed that alanine is not an effective inhibitor for aluminium corrosion due to its low inhibition efficiency.