Spectroscopic Investigations of Physicochemical Interactions on Mild Steel in an Acidic Medium by Environmentally Friendly Green Inhibitors

Abstract

The influences of Polycarpaea corymbosa (PC) and Desmodium triflorum (DT) leaf extracts on the corrosion behavior of mild steel (MS) in 1.0 M HCl was investigated by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. The effect of temperature on the corrosion behavior of MS in 1.0 M HCl with the addition of plant extracts was studied in the temperature range of 300 K-320 ± 1 K. The results revealed that PC and DT were excellent green inhibitors and the inhibition efficiencies obtained from weight loss and electrochemical experiments were in good agreement. Inhibition efficiencies up to 91.78 % for PC and 92.99 % for DT were obtained. Potentiodynamic polarization studies revealed that both the inhibitors behaved as mixed-type inhibitors. Adsorption behavior of these green inhibitors on the MS surface was found to obey the Langmuir adsorption isotherm. The thermodynamic parameter values of free energy of adsorption (DG ads ) and enthalpy of adsorption (DH ads ) revealed that each inhibitor was adsorbed on the MS surface via both chemisorption and physisorption mechanisms. The adsorption mechanism of inhibition was supported by FT-IR, UV-Visible, WAXD and SEM-EDS.

Synergistic effect of polyethylene glycols and rare earth Ce4+ on the corrosion inhibition of carbon steel in sulfuric acid solution: electrochemical, computational, and surface morphology studies

“…This phase angle shift is due to the formation of a protective layer on the steel surface by PEGs and/or PEGs/Ce 4? molecules, which changes the electrode interfacial structure [37,38]. Figure 7a, b shows a comparison of the simulated spectrum and the experimental EIS data, using ZView impedance fitting software for carbon steel samples immersed in 0.1 M H 2 SO 4 in the absence and presence of 25 mg l -1 Ce 4?…”

Anticorrosive assay-guided isolation of active phytoconstituents from Anthemis pseudocotula extracts and a detailed study of their effects on the corrosion of mild steel in acidic media

“…3 Several synthetic molecules have been reported as valuable corrosion inhibitors for metals. [12][13][14][15] For example, the reported plant extracts with promising corrosion inhibitive properties include Zanthoxylum alatum, 9 Phyllanthus amarus, 13 Uncaria gambir, 10 Strychnos nux-vomica, 16 Murraya koenigii, 7 Schinopsis lorentzii, 17 Phragmites australis, 14 Brugmansia suaveolens, Cassia roxburghii, 11 Polycarpaea corymbosa and Desmodium triorum. The toxicity of synthetic compounds and uncompromising environmental directives have led to the use of natural products as safe and effective green corrosion inhibitors.…”

“…4,5 However, most of them are expensive and extremely toxic to human being and the environment. 15 Although several plant extracts have been described to be prominent corrosion inhibitors for metals in different corrosive media, it has been well established that the inhibitive actions of plant extracts originate from the mixture of organic molecules in their composition. [6][7][8] Natural products have the advantage of being biodegradable in nature, renewable, easily accessible, economical and, most importantly, are environmental friendly.…”

Novel Biobased Nonionic Surfactants: Synthesis, Surface Activity and Corrosion Inhibition Efficiency Against Aluminum Alloy Dissolution in Acidic Media

“…This can be attributed to the effect of alkyl chains attached to the inhibitors and their chemical nature. It was reported [27][28][29] that inhibition efficiency of the inhibitors within homologous series increases by increasing the alkyl chain length and also by increasing the unsaturation sites in these chains.…”

“…Olive oil [4], palm kernel [5], tallow [6], lard or fish oil [7], coconut oil [8], castor oil [9], and jatropha oil, are wide spread since it is easy to attain surface active agents through simple reactions [9,10]. In addition to cleaning and home applications of nonionic surfactants, they play an effective role as cutting fluid additives [11], emulsifiers [12], demulsifiers [13], and corrosion inhibitors [14][15][16]. In this study, we prepared four nonionic surfactants by reacting propylene oxide with oleic acid, linoleic acid, and fatty acids obtained from jatropha oil after alkaline hydrolysis.…”