Adsorption and Inhibitive Properties of Leaf Extract of Newbouldia leavis as a Green Inhibitor for Aluminium Alloy in H2SO4

Abstract

The corrosion inhibition of Al and its alloys is the subject of tremendous technological importance due to the increased industrial applications of these materials. This study reports the corrosion inhibition of AA8011 aluminium alloy in acidic solutions using Newbouldia leavis leaf extract by way of gravimetric measurements. It was shown that the presence of Newbouldia leavis leaf extract inhibited the corrosion of aluminium in the test solutions and the inhibition efficiency depended on the concentration of the plant extract as well as on the time of exposure of the aluminium samples in H 2 SO 4 solutions containing the extract. The experimental data complied to the Langmuir adsorption isotherm and the value and sign of the Gibb's free energy of adsorption obtained suggested that inhibitor molecules have been spontaneously adsorbed onto the aluminium surface through a physical adsorption mechanism.

Determination of Adsorption Isotherm model best fit for methanol leaf extract of Securinega virosa as corrosion inhibitor for corrosion of mild steel in HCl

“…Taking this into cognisance, therefore, the data for this plant extract can be said to fit well into the Langmuir, Freundlich, Temkin, Flory-Huggins and Adejo-Ekwenchi isotherms ( Table 2). The values of equilibrium constant, Kads, of all the isotherms (Table 2) are all positive, implicitly, indicative of favourable adsorption [7]. The Sshaped curve of the plot of %IE against the logarithm of concentration as depicted by Figure 1 (at 313 K) further attests to the fact that an adsorbed layer was actually formed on the metal surface by the extract [7,22].…”

“…The establishment of adsorption equilibrium correlation is indispensible for the prediction of reliable adsorption parameters [3]. For example, in corrosion inhibition process the mechanism of inhibition can better be understood through the use of isotherms [7,8].…”

Inhibition of mild steel corrosion using Jatropha Curcas leaf extract

“…Hence, naturally occurring compounds from plants origin have been a subject of interest for researchers because of their abundant availability, cost effectiveness and environmentally friendly [4]. Several studies have been carried out on the use of these naturally occurring compounds as corrosion inhibitors for metals in different media [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19].…”

Glutamic Acid as Corrosion Inhibitor for Aluminium in Acidic Medium

“…This result shows that the inhibitory action of these compounds depends on the potential for higher potential inhibitory character disappears. It is generally accepted that the first step in the adsorption of glutamic acid on the metal surface usually involves the replacement of one or more water molecules adsorbed at the metal surface [22].…”