ABSTRACT In the industrial use of metal structures, corrosion has a very serious impact on the durability and cost efficiency of the structures. This article demonstrated that microencapsulated Aloe vera has a great potential as an environmentally friendly corrosion inhibitor for mild steel in a simulated alkaline environment. This study involved the incorporation of aloe vera extract in alginate microcapsules, which allows the active compounds to be released in a controlled manner, and the limitation of short‐term period of protection that is observed to be exhibited by the free plant‐extract inhibitors. Preparation of the microcapsules was done using various concentrations of aloe vera extract from 1% to 3%. The corrosion behavior was evaluated using electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM), and the corrosion rates after 7, 14, and 21 days were estimated using weight loss method. Findings indicated that the sample with 1% of alginate and 1% of aloe vera had the lowest rates of corrosion, as it declined by 0.79 mm/yr at 7 days to 0.20 mm/yr at 21 days. This shows that there was a long‐term inhibitory effect that was enhanced with the length of immersion. The concentration of aloe vera increased the inhibition effect, proving the role of the encapsulated extract. SEM analysis indicated severe corrosion in uninhibited samples, while samples with microencapsulated Aloe vera showed fewer defects and more compact surfaces. These results showed that aloe vera microcapsules can be used successfully to reduce the corrosion damage and enhance surface integrity, as well as provide the sustainable alternative to synthetic inhibitors. Microencapsulation of aloe vera in corrosion inhibition under alkaline conditions can be useful in industrial corrosion control, as it can increase the longevity of metals and minimize costs.
Yacoob et al. (Wed,) studied this question.