Synthesis and Characterization of Carbon Steel Corrosion Inhibitors Based on 4,5,6,7-tetrahydrobenzo[b]thiophene Scaffold

Protection of Metals and Physical Chemistry of Surfaces - Three novel inhibitors based on 4,5,6,7-tetrahydrobenzo[b]thiophene scaffold were synthesized and characterized. The inhibitive action of...     

Effect of some amidopoly ethylamine on corrosion of zinc electrode used in zinc-manganese batteries

The effect of addition of some amidopoly ethylamine, with different numbers of ethylamine units, on the corrosion of zinc electrode in 35% ZnCl₂, (26% ZnCl₂ + 8.8% NH₄Cl), (8.8% ZnCl₂ + 26% NH₄Cl) and 26% NH₄Cl electrolytes has been studied using galvanostatic polarization measurements and hydroden evolution reaction (HER). The effect of the addition on discharge and shelf life of Zn-manganese batteries has been studied. The results showed that the inhibition efficiency increases with increasing number of ethylamine units per molecule. Inhibition is explained on the basis of adsorption of amidopoly ethylamine molecules on the zinc electrode surface through their ethylamine groups.     

A novel green inhibitor for C-steel corrosion in 2.0 mol·L~(-1) hydrochloric acid solution

The corrosion inhibition characteristics of aqueous extract of seeds of Melia azedarach L.(MA) have been studied as eco-friendly green inhibitor for corrosion control of C-steel in 2 mol·L~(-1) HCl solution by gravimetric and electrochemical methods. The results depict that, the extract inhibits efficiently the corrosion of carbon steel in hydrochloric acid. The efficiency of extract is increased with increasing the extract concentration but independent on the studied temperature. The adsorption of the extract components onto the steel surface was found to be spontaneous, and follows Langmuir adsorption isotherm. The surface morphology of C-steel, in the absence and presence of MA extract in 2.0 mol·L~(-1) hydrochloric acid solution, was studied using scanning electron microscopy(SEM).     

Gelatin as corrosion inhibitor for aluminum and aluminum silicon alloys in sodium hydroxide solutions

The corrosion behavior of aluminum and aluminum silicon alloys in 0.1 M NaOH solution in the absence and presence of gelatin was studied using potentiostat polarization, electrochemical impedance spectroscopy (EIS), cyclic voltammetry and potentiodynamic anodic polarization techniques. The percentage inhibition efficiency increases with increasing the concentration of gelatin and with decreasing temperature as well as Si content. This was attributed to a lower affinity of the inhibitor to adsorb on Si than on Al. The inhibitory action of gelatin was explained in terms of adsorption of gelatin on the surface of Al or Al–Si alloys forming a barrier of mass and charge transfer leading to protect the metal surface from the aggressive ones. The adsorption of gelatin on the metal surface follows Freundlich isotherm. Some activated thermodynamic parameters were calculated and discussed.     

Inhibition of aluminum corrosion using Opuntia extract

The inhibitive action of the mucilage extracted from the modified stems of prickly pears, toward acid corrosion of aluminum, is tested using weight loss, thermometry, hydrogen evolution and polarization techniques. It was found that the extract acts as a good corrosion inhibitor for aluminum corrosion in 2.0 M HCl solution. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm. It was found that the adsorption of the extract on aluminum surface is a spontaneous process. The inhibition efficiency (IE) increases as the extract concentration is increased. The effect of temperature on the IE was studied. It was found that the presence of extract increases the activation energy of the corrosion reaction. Moreover, the thermodynamic parameters of the adsorption process were calculated. It was found also that the Opuntia extract provides a good protection to aluminum against pitting corrosion in chloride ion containing solutions.