Novel Schiff base-based cationic Gemini surfactants as corrosion inhibitors for Q235 carbon steel and printed circuit boards

Synthesis of Gemini-type imidazoline quaternary ammonium salt using by-product fatty acid as corrosion inhibitor for Q235 steel

Gemini-type imidazoline quaternary ammonium salt is a new type of environmentally friendly corrosion inhibitor has been widely used in engineering materials. However, most of them are hazardous/toxic compounds derived from petroleum-based products, which did harm to environment. In this work, an environmentally friendly Gemini-shaped imidazoline quaternary ammonium salt corrosion inhibitor (G211) was synthesized using cheap fatty acid recycled from dimer acid industry as feedstock. The corrosion inhibition effects of G211 on Q235 steel in 1 M HCl solution were investigated through weight loss experiments, potential polarization curves, and alternating current impedance spectroscopy experiments. The results show that the inhibition rate of G211 as a mixed-type inhibitor is up to 94.4% and the concentration drop as low as 500 ppm at 25 ℃. The adsorption of G211 on Q235 surface follows Langmuir adsorption isothermal curve. The chemical composition of the Q235 steel surface was analyzed through scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Furthermore, the possible corrosion inhibition mechanism of G211 on the surface of Q235 steel is proposed. This article not only presents an outstanding solution for safeguarding Q235 steel against corrosion but also introduces a feasible method for high-value utilization of monomer acid (MA).

Insights into the Corrosion Inhibition Mechanism of Canavalia gladiata Leaf Extract for Copper in Sulfuric Acid Medium

Canavalia gladiata leaf extract (CGLE) is extracted from crop waste employing a water decoction method. By employing electrochemical techniques, morphology analysis, quantum chemical calculations, and other methods, we extensively investigated the anticorrosion efficacy of CGLE on copper within a H2SO4 solution. The outcomes reveal that at 298 K, a CGLE concentration of 800 mg/L attains a remarkable inhibition efficiency (IE) of 96.8%. Additionally, we examined the impact of CGLE on the corrosion resistance of copper at varying temperatures. Even with rising temperatures, CGLE manages to sustain an IE of over 95%. This indicates that CGLE is mainly chemisorption based on the copper, leading to a strong adsorption. The surface test results show a noteworthy decrease in the extent of copper surface corrosion upon the introduction of CGLE. The study of the adsorption model demonstrates the alignment of CGLE adsorption onto the copper with the Langmuir adsorption.

Environmentally Benign Water-Soluble Sodium L-2-(1-Imidazolyl) Alkanoic Acids as New Corrosion Inhibitors for Mild Steel in Artificial Seawater

Three novel natural amino acid-derived sodium L-2-(1-imidazolyl) alkanoic acids (IZSs), namely, sodium 2-(1H-imidazol-1-yl)-4-methylpentanoate (IZS-L), sodium 2-(1H-imidazol-1-yl)-3-phenylpropanoate (IZS-P), and sodium 2-(1H-imidazol-1-yl)-4-(methylthio)butanoate (IZS-M), were investigated as corrosion inhibitors. The IZSs were synthesized following the green chemistry principles, and their structure was characterized using FTIR and NMR techniques. The corrosion study results reveal that a moderate concentration of IZSs (having low solution conductivity) showed potential corrosion inhibition for mild steel in artificial seawater. At longer immersion, IZS-P forms a uniform protective film and exhibits the potential inhibition efficiency of 82.46% at 8.4 mmol L^-1. Tafel polarization results reveal that IZS-P and IZS-M act as mixed types with an anodic predominantly corrosion inhibitor. The electrochemical impedance spectroscopy results signify that IZSs inhibit mild steel corrosion through the formation of an inhibitor film on the metal surface, which was further confirmed by the FTIR, SEM, EDX, and XPS studies. DFT result shows that in IZS-P, the benzylic group (-CH₂-Ph) has greater electron distribution compared to isobutyl (-CH₂CH(CH₃)₂) in IZS-L and methythioethyl group (-CH₂CH₂SCH₃) which supported the corrosion inhibition performance at longer immersion [IZS-P (82.46%) > IZS-M (67.19%) > IZS-L (24.77%)].

Coco Monoethanolamide Surfactant as a Sustainable Corrosion Inhibitor for Mild Steel: Theoretical and Experimental Investigations

Recent studies indicate that surfactants are a relatively new and effective class of corrosion inhibitors that almost entirely meet the criteria for a chemical to be used as an aqueous phase corrosion inhibitor. They possess the ideal hydrophilicity to hydrophobicity ratio, which is crucial for effective interfacial interactions. In this study, a coconut-based non-ionic surfactant, namely, coco monoethanolamide (CMEA), was investigated for corrosion inhibition behaviour against mild steel (MS) in 1 M HCl employing the experimental and computational techniques. The surface morphology was studied employing the scanning electron microscope (SEM), atomic force microscope (AFM), and contact measurements. The critical micelle concentration (CMC) was evaluated to be 0.556 mM and the surface tension corresponding to the CMC was 65.28 mN/m. CMEA manifests the best inhibition efficiency (η%) of 99.01% at 0.6163 mM (at 60 °C). CMEA performs as a mixed-type inhibitor and its adsorption at the MS/1 M HCl interface followed the Langmuir isotherm. The theoretical findings from density functional theory (DFT), Monte Carlo (MC), and molecular dynamics (MD) simulations accorded with the experimental findings. The MC simulation's assessment of CMEA's high adsorption energy (-185 Kcal/mol) proved that the CMEA efficiently and spontaneously adsorbs at the interface.

Theoretical and electrochemical evaluation of tetra-cationic surfactant as corrosion inhibitor for carbon steel in 1 M HCl

Recently, scientist study the role of surfactants for carbon steel corrosion protection. In the present study, newly tetra-cationic surfactant (CS4: 1,N1'-(ethane-1,2-diyl) bis (N1, N2-didodecyl-N2-(2- (((E)-3-hydroxy-4-methoxy-benzylidene)amino)ethyl)ethane-1,2-diaminium) chloride) based on Schiff-base compound(5,5'-((1E,17E)-2,5,8,11,14,17-hexaazaoctadeca-1,17-diene-1,18-diyl)bis(2-methoxyphenol) was synthesised, purified and characterized using FTIR and ¹HNMR spectroscopy. The synthesized Tetra-cationic surfactant (CS4) was evaluated as anti-corrosion for carbon steel (CS-metal) in aggressive 1 M HCl using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques (PDP). CS4 compound had a good surface-active property by reducing the surface tension as a result to the hydrophobic chains role. The prepared CS4 behaved as hybrid inhibitor (mixed-type) by blocking the anodic and cathodic sites. CS4 exhibited good inhibition efficiency reached 95.69%. The surface morphology of CS-metal was studied using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS)confirming the anti-corrosive effect of CS4 compound returned into the adsorption process of CS4 molecules over CS-metal which obeyed Langmuir adsorption isotherm. The inhibitive effect of CS4 was supported by theoretical quantum chemical studies using the density functional theory (DFT), Monte Carlo (MC) and Molecular Dynamic (MD) simulation.

Suppression of steel corrosion via some gemini cationic surfactant-based Schiff base: experimental and theoretical investigations

Steel is involved extensively in engineering vast constructing units in many industries and can undergo to corrosion by some chemical and/or electrochemical reactions with the environment. Therefore, designating an organic inhibitor with a specific chemical structure will participate in steel protection via enhancing their adsorption on the steel surface. Three gemini cationic surfactants based on azomethine with different hydrophobic tails labeled GSBI8, GSBI12, and GSBI16 have been designated and evaluated as corrosion inhibitors utilizing electrochemical impedance spectroscopy (EIS), gravimetrical and potentiodynamic polarization techniques. Importantly, the surfactant tail regulated the corrosion inhibition performance; with increasing the surfactant tail length, their inhibition efficiency enhanced because of their higher adsorption affinity. The inhibition efficiency of GSBI8, GSBI12, and GSBI16 reached 95.52, 96.72, and 97.1% respectively (EIS measurements). The Tafel examination clarified that GSBI8, GSBI12, and GSBI16 inhibitors behave as mixed type inhibitors following the modified Langmuir isotherm. The inhibitors adsorption on C-steel was confirmed by SEM surface examination. Finally, the DFT and MCs point of views investigation supported the experimental performance of the tested GSBI8, GSBI12, and GSBI16 inhibitors and specially their dependence on surfactant tail length.

Experimental and theoretical study on the corrosion inhibition of mild steel by nonanedioic acid derivative in hydrochloric acid solution

The corrosion performance of mild steel (MS) in 1M HCl solution was examined by weight loss (WL), potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (EFM), and open circuit potential (OCP) measurements in the absence and presence of nonanedihydrazide. PDP measurements indicated that nonanedihydrazide acts as a mixed inhibitor due to its adsorption on the MS surface, exhibiting an inhibition efficiency of more than 97%. The surface morphology investigation of the protective layer on the MS surface confirmed that adsorption of nonanedihydrazide molecules occurred via chemical adsorption following Langmuir's isotherm model. The effect of temperature on the corrosion performance in the presence of nonanedihydrazide was investigated in the range of 303-333 K, showing that the inhibition efficiency increased with an increase in the inhibitor concentration and decreased with an increase in temperature. A new green corrosion inhibitor was synthesised and theoretical computations were conducted to completely understand the inhibition mechanism. Nonanedihydrazide molecules were investigated by DFT (density functional theory) using the B3LYP functional to evaluate the relationship of corrosion inhibition performance and the molecular structure. The computed theoretical parameters presented significant support for understanding the inhibitive mechanism revealed by the inhibitory molecules and are in good agreement with WL, PDP, EIS, (EFM), and OCP results.

Use of a Gemini-Surfactant Synthesized from the Mango Seed Oil as a CO2-Corrosion Inhibitor for X-120 Steel

A gemini surfactant imidazoline type, namely N-(3-(2-fatty-4,5-dihydro-1H-imidazol-1-yl) propyl) fatty amide, has been obtained from the fatty acids contained in the mango seed and used as a CO₂ corrosion inhibitor for API X-120 pipeline steel. Employed techniques involved potentiodynamic polarization curves, linear polarization resistance, and electrochemical impedance spectroscopy. These tests were supported by detailed scanning electronic microscopy (SEM) and Raman spectroscopy studies. It was found that obtained gemini surfactant greatly decreases the steel corrosion rate by retarding both anodic and cathodic electrochemical reactions, with an efficiency that increases with an increase in its concentration. Gemini surfactant inhibits the corrosion of steel by the adsorption mechanism, and it is adsorbed on to the steel surface according to a Langmuir model in a chemical type of adsorption. SEM and Raman results shown the presence of the inhibitor on the steel surface.