Synergistic Influence of Gum Arabic and Iodide Ion on the Corrosion Inhibition of Aluminium in Alkaline Medium

Abstract

The effect of iodide ion on the corrosion inhibition of aluminium in NaOH in the presence of Gum Arabic (GA) was studied using weight loss and hydrogen evolution techniques at 303 and 313 K. The results obtained showed that inhibition efficiency increased with increasing GA concentration. The inhibiting action of GA was considerably enhanced by the addition of KI. The adsorption of KI, GA alone and in combination with iodide ion was found to obey Temkin adsorption isotherm. The inhibiting effect of GA and (GA+KI) increased with increase in temperature of the corrosion medium, indicating chemical adsorption mechanism. Synergism parameter evaluated was found to be greater than unity for the different concentrations of GA, which shows that the enhanced inhibition of GA caused by the addition of iodide ion is due to synergistic effect. It could be deduced from the thermodynamic parameters obtained that adsorption of GA alone and in combination with KI onto the metal surface is spontaneous.

Green corrosion inhibitors for aluminium and its alloys: a review

“…14,15,[147][148][149][150][151][152][153][154][155][156][157] Xanthan, Commiphora pedunculata, and arabic gums were used without further purication. 15,147,149,155,156 Two different methods 158,159 were used to purify the other gums in the above studies. Purication of the gums through dissolution in 95% ethanol 158 was employed for Raphia hookeri, 14 Pachylobus edulis, 148 and Dacroydes edulis.…”

A Mixture of Iodide Ion and Gum Exudates of Eucalyptus globules as Green Inhibitor for Dissolution Control of Mild Steel in 1 N HCl Medium

“…The adhesive nature or binding capacity of GEG on mild steel in 1 N HCl is found to be less significant at higher temperature. Therefore the adsorption strength as well as corrosion inhibition effectiveness of GEG on mild steel surface can be synergistically enhanced using iodide ions which are good ligands [3][4][5][6][7][8]. Therefore in present study the synergistic corrosion inhibition effect of iodide ion with GEG on the dissolution control of mild steel in 1 N HCl at 303-323 K has also been studied.…”

“…In HCl medium the mild steel surface gets polarized and behaves as positively charged. Iodide ion present in mixture strongly interact with mild steel surface through electrostatic interaction on Fe 2+ ion of mild steel due to its large ionic radius, high hydrophobicity and low electronegativity [3][4][5][6][7][8]. After stabilization of positive charge (Fe 2+ ), the iodide ions are strongly adsorbed on mild steel surface, which results with development of excess negative charge on mild steel surface.…”

“…Simultaneously presence of GEG in aggressive medium undergoes acid hydrolysis and produces monomers of carbohydrates and proteins units. Now adsorbed iodide ions act as intermediate bridge between positively charged mild steel surface and labile electrons of hetero atoms present in hydrolyzed monomers of GEG such as carbohydrates and proteins units [3][4][5][6][7][8]. Stabilization of the adsorbed iodide ions by means of interaction with the GEG leads to grater surface coverage arising from the ion-pair interactions between the organic constituents of GEG and iodide ion.…”

Electrochemical and computational study of gumexudatesfromCanarium schweinfurthiias green corrosion inhibitor for mild steel in HCl solution

“…The use of gum exudates (a natural polymer from plant) to inhibit the corrosion of metals in acidic and alkaline environment is on the increase as they have been found to be cheap, biodegradable and comply with required environmental standards that vitiated the abolition of chromates and other non-eco-friendly inhibitors [8,9]. The inhibitive properties of plant gum exudates from Acacia trees [10], Guar [11], oleo-gum [12] Raphia [13], Khaya [14] and Ficus [5], have been reported.…”