Meloxiam as corrosion inhibitor for Aluminum in acid media Experimental and theoretical study

Abstract

The effects of Meloxiam drug (MEL) on the corrosion of pure aluminum in 2 M HCl have been
investigated using weight loss methods. The measurement showed that the inhibition efficiency increased with increase in the concentration of inhibitor. The adsorption of the inhibitors on the aluminum surface obeyed Langmuir adsorption isotherm and had a physical mechanism. The effect of temperature on the corrosion behavior in the presence of different concentration of the MEL inhibitors was studied in the temperature range of 25–65 °C. The associated activation energy of corrosion Ea and other thermodynamic parameters such as ΔH0 ads ,ΔS0ads , (Kads) and ΔG0 ads were calculated to elaborate the mechanism of corrosion inhibition. Quantum chemical parameter such as HOMO,LUOM and Mulliken charge etc. have been calculated using DFT (B3LYP/ 6- 311++G(d,p)),The results indicate that N and S atoms in the MEL structure was not effected in the adsorption of drug on the Al surface .