Spilanthes acmella Leaves Extract for Corrosion Inhibition in Acid Medium

Abstract

In the present study, the corrosion inhibition effect of Spilanthes acmella aqueous leaves extract (SA-LE) on mild steel was investigated in 1.0 M HCl solution at different temperature using weight loss, Tafel polarization, linear polarization resistance (LPR), and electrochemical impedance (EIS) measurements. Adsorption of inhibitor on the surface of the mild steel obeyed both Langmuir and Temkin adsorption isotherms. The thermodynamic and kinetic parameters were also calculated to determine the mechanism of corrosion inhibition. The inhibition efficiency was found to increase with an increase in the inhibitor concentration i.e., Spilanthes acmella aqueous leaves extract, however, the inhibition efficiency decreased with an increase in the temperature. The phytochemical constituents with functional groups including electronegative hetero atoms such as N, O, and S in the extract adsorbed on the metal surface are found responsible for the effective performance of the inhibitor, which was confirmed by Fourier-transform infrared spectroscopy (FT-IR) and ultraviolet–visible spectroscopic (UV-Vis) studies. Protective film formation against corrosion was confirmed by scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle studies. The result shows that the leaves extract acts as corrosion inhibitor and is able to promote surface protection by blocking active sites on the metal.

Application of a Mix of Vegetables Residues as Inhibitor for Carbon Steel

“…The maintenance of the aspect of the diagrams when the inhibitors were added to the solution suggests that the compounds only delay the corrosive process, without modifying its mechanism. Similar behavior has been observed in other studies in the literature [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] . The synergism of CBP and PKCP in the highest studied concentration with 1.11 g/L of each component, presented the highest impedance value, It can be observed that in the presence of any inhibitor concentration, in comparison to the control system, the presented time constant results in phase angle values in a wider frequency range, indicating a deceleration in the reactions involved.…”

“…Some synthetic corrosion inhibitors have toxic properties that are harmful to the environment and human health. In this context, the use of natural inhibitors is beneficial both financially and environmentally, due to their biodegradability, ecological acceptance, and renewability 3 This includes, for example, Boswellia serrata 4 , Theobrama cacao 5 , Glycyrrhuza glabra 6 , and some vegetables, such as the garlic peel 7 , Xanthium strumarion 8 , castor bark 9 Cotton Seed 10 , Spilanthes acmella Leaves 11 , widely distributed and low economic value, including byproducts of agro-industrial processes and agricultural waste 12 .…”

Corrosion inhibition behaviour on carbon steel in well-water by Ethanolic extract of Portulaca quadrifida (Chicken weed) leaves

“…The https://www.indjst.org/ Root mean square roughness, Average Roughness and Maximum Peak-to-valley (P-V) height values for carbon steel immersed in well-water are 13.17nm, 1476.12nm, and 3791.00nm. these values suggest that the producing greater surface roughness compared with polished carbon steel surface, due to rate of corrosion is increases on carbon steel surface in well-water when carbon steel is immersed in well-water containing 500ppm of PQ and 30ppm of Zn 2+ , the Average Roughness value is reduced to 12.74nm from 1317.08nm, Root mean square roughness (R rms ) value was decreased to17.89nm from 1476.12nm as well as Maximum Peak-to-valley (P-V) height value reduced to 102.31nm from 3791.00nm, these parameters values are confirmed that the smoother surface appears over carbon steel specimen, due to the produces safe layer (nano-layer) (45) of Fe 2+ -PQ extract complex and Zn(OH) 2 on the carbon steel surface. From the above images, Figure 8 (a) for polished carbon steel surface is uncorroded carbon steel surface due to small roughness was obtained on polished carbon steel surface by atmospheric corrosion.…”

Corrosion inhibition and thermodynamic studies on carbon steel in well water by ethanolic extract of Alpinia officinarum leaves (Lesser galangal)-Zn2+

“…Result of thermodynamic parameters are given in Table 7 . The ∆G ads (53,61) , q ads (27) and ∆S ads (4,28,58) values are calculated using the following equations.…”

“…Langmuir (29,31,50,53,58) , Flory-Huggins (30,62,63) , EL-Awady (30,63,66) and Temkin (30,61,63) isotherms are expressed by following equations.…”