Experimental Investigation of the Inhibiting Action of Adenine on the Corrosion of Mild Steel in Acidic Environments

Abstract

Corrosion inhibition of mild steel by adenine (AD) in 0.1 M solutions of HCl and H 2 SO 4 was investigated using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy techniques. The study was carried out at 30°C and 60°C respectively. The effect of iodide ions on inhibition efficiency was also assessed. Results showed that AD had a moderate inhibitive effect on the acid corrosion of mild in the order HCl > H 2 SO 4 at 30°C and H 2 SO 4 > HCl at 60°C. The presence of iodide ions in the acid media increased the efficiency of AD. From potentiodynamic polarization studies, it was observed that AD alone and the mixture of AD+KI surpressed both the anodic and cathodic partial reactions. The corrosion processes were inhibited by adsorption of AD onto the mild steel surface in a concentration and temperature-dependent manner. Langmuir isotherm was used to explain the adsorptive characteristics of AD.

Influence of Cissus populnea stem extract on kinetics and thermodynamics of mild steel corrosion in acidic medium

“…Reacting species become more energetic with a rise in temperature, this explains the increased rates of corrosion of the mild steel in both the uninhibited and inhibited test solutions at higher temperatures. This observation is corroborated by other researchers [16,20,24,25]. However, the rate of corrosion of mild steel was relatively lower in the inhibited test solutions compared with the free acid solutions.…”

Lepidagathis alopecuroides methanol extract as corrosion inhibitor for mild steel in HCl

“…The anodic and cathodic Tafel curves were extrapolated to corrosion potential to obtain the corrosion current densities ( ) [14]. Inhibition efficiency was calculated using Equation 4 [5,20]:…”

“…( ℎ) is the corrosion current density of the steel coupon in the presence of L. alopecuroides [5,20].…”

“…The application of corrosion inhibitor formulations on steel structures is an effective and practical approach in mitigating the corrosion of steel parts exposed to different kinds of electrolytes [1,2]. These formulations usually contain chemical compounds that possess hetero-atoms like oxygen, nitrogen and sulfur in aromatic or conjugated systems which serve as adsorption centers to the steel surface [3][4][5][6][7].…”

“…Most of these compounds are however toxic and are sources of environmental and health concerns. Hence, there is the need to search for environmentally friendly substitutes [3][4][5][6][7].…”