An improved corrosion resistance of mild steel in acidic solution using aloe vera extract

Abstract

Corrosion is a natural process and unfavourable occurrence when pipeline metals and alloys react with their surrounding environment, cause undesirable damage, and create harmful environment. This issue has resulted in substantial economic losses and posed significant safety concerns. In order to overcome these problems, typically, the industry employs the use of green inhibitors corrosion to safeguard metal surfaces from corrosive agents. However, commercial inhibitors pose a danger and toxic to both the environment and human health. Therefore, as a solution to those problem, green corrosion inhibitor has been found to be both effective and economically feasible, performing similarly to commercial inhibitors. This study aims to examine the efficacy of Aloe Vera extract as a green inhibitor of corrosion in mild steel in a 1M H2SO4 solution. Weight loss, Potentiodynamic polarization, Electrochemical Impedance Spectroscopy (EIS) and Scanning Electron Microscopy (SEM) studies were conducted in a 1M H2SO4 solution towards mild steel to analyse the effect of Aloe Vera as an effective corrosion inhibitor. It has been found that as the concentration of inhibitors increases, inhibitor efficiency also increases. Weight loss measurement has proven that the inhibition efficiency increased and reached to maximum values of 90.81 % after 8 h exposure time for 800 ppm concentration. Potentiodynamic polarization result also shown similar trend with weight loss where the corrosion rate is reduced with inhibitive efficiency with higher concentration of Aloe Vera content in the acidic solution. The result obtained from EIS shows one depressed capacitive loop where the capacitive loops diameter was bigger in presence of higher Aloe Vera content which suggested bigger imaginary film that protecting the surface. SEM analysis revealed a significant decrease in the roughness of mild steel surface after the addition of an inhibitor, which support the inhibitor efficiency of protecting the mild steel surface from the corrosive medium.