Corrosion inhibition of aluminium in acid solutions by some imidazoline derivatives

Abstract

2-Pentadecyl-1,3-imidazoline (PDI), 2-Undecyl-1,3-imidazoline (UDI), 2-Heptadecyl-1,3-imidazoline (HDI), 2-Nonyl-1,3-imidazoline (NI) were synthesized and characterized by FT-IR and NMR Studies. The corrosion inhibition properties of these compounds on aluminium in 1 M HCl and 0.5 M H 2 SO 4 were investigated by weight loss, potentiodynamic polarization, electrochemical impedance and scanning electron microscopic techniques. The weight loss study showed that the inhibition efficiency increases with increase in the concentration of the inhibitor and was found to be inversely related to time and temperature while it shows no significant change with increase in acid concentration. The effectiveness of these inhibitors were in the order of UDI > NI > PDI > HDI .The values of activation energy, free energy of adsorption, heat of adsorption, enthalpy of activation and entropy of activation were also calculated to elaborate the mechanism of corrosion inhibition. The adsorption of these compounds on aluminium surface follows the Langmuir adsorption isotherm. The potentiodynamic polarization data show that the compounds studied are mixed type inhibitors. Electrochemical impedance was used to investigate the mechanism of corrosion inhibition. The surface characteristics of inhibited and uninhibited metal samples were investigated by scanning electron microscopy (SEM).

Inhibitive properties, thermodynamic, kinetics and quantum chemical calculations of polydentate Schiff base compounds as corrosion inhibitors for iron in acidic and alkaline media

“…Several adsorption isotherms were assessed, and the Temkin adsorption isotherm was found to provide the best description of the adsorption behavior of the investigated inhibitors. The Temkin isotherm is given by the equation [54]:…”

Electrochemical and Quantum Chemical Studies of 1, 2, 3-Benzotriazole as Inhibitor for Copper and Steel in Simulated Tap Water

“…A chemisorption is a strong interaction in which the electronic states of the inhibitor molecules hybridize with the metal electron state [43][44][45][46][47][48][49] . The interaction between BTAH and metal surface is associated with the π-electron of BTAH and the d-orbital of metal surface, which could be regarded as the chemisorptions.…”

Ionic Liquids as Electrodeposition Additives and Corrosion Inhibitors

“…Since the imidazolium group as well as nitrogen atom in the heteroaromatic ring of imidazolium compounds can be protonated in acidic solutions [117]. The protonated inhibitor molecules can be adsorbed through electrostatic interactions between the positively charged molecules and the negatively charged metal surface [2].…”