Mild Steel In Sulfuric Acid Research Articles

Inhibitory Potential of N-Methyl Formanilide on Mild Steel Corrosion in Sulfuric Acid: Quantum Chemical and Experimental Perspectives

Technological progress has led to increased use of metals and alloys such as aluminum, brass, bronze and mild steel. While mild steel is favoured for its availability, low cost and excellent mechanical properties, it is prone to corrosion. This study aims to reduce the corrosion of mild steel in sulfuric acid using N-methyl formanilide (NMF) as an inhibitor. The effectiveness of NMF was evaluated using gravimetric method (weight loss) and electrochemical impedance spectroscopy (EIS). Surface analyses were conducted using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The study examined the performance of NMF at different temperatures (298 K to 338 K) and varying inhibitor concentrations. The results indicated that the percentage inhibition efficiency (%IE) of NMF increased with higher concentration but decreased with temperature. The NMF formed a protective layer on mild steel through physical adsorption, which was confirmed by El-Awady adsorption isotherm and comparing it with other adsorption models. The kinetic and thermodynamic studies were also performed, with activation energy (Ea) and adsorption free energy (ΔG°ads) being calculated. These findings were further validated using the AM1 quantum mechanical method, revealing the promising results for the investigation.

Evaluation of inhibition performance of methylimidazolium ionic liquids on surface of mild steel in sulfuric acid

In the present study, the microwave irradiation approach was used to synthesize two methylimidazolium-based ionic liquids (MImILs), specifically 1-Heptyl-3-methylimidazolium bromide [HMImBr] and 1-Benzyl-3-methylimidazolium bromide [BzMImBr]. Several spectroscopic methods have been used to characterize the produced compounds. Gravimetric and electrochemical techniques were employed to examine their ability to prevent corrosion of the mild steel in a 0.5 M sulfuric acid solution. Amongst all the evaluated ionic liquids, [BzMImBr] having an aromatic ring instead of hexyl ((–CH2)5–CH3) hydrocarbon of [HMImBr] manifests better inhibition efficiency of 95.49 % at 1000 ppm concentration. The experimental ionic liquids negatively impact both the anodic and cathodic Tafel reactions, exhibiting mixed-type inhibition properties, as demonstrated by the findings of the potentiodynamic polarization investigations. Through their adsorption employing their electron-rich centres, the examined ionic liquids create a corrosion-protective covering, and their adsorption follows the Langmuir isotherm model. Negative values of ΔGads indicate the spontaneous nature of [HMImBr] and [BzMImBr] adsorption, whereas values between −20 and −40 KJ mol−1 indicate the physio-chemisorption mode of adsorption. Energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), and field emission-scanning electron microscopy (FE-SEM) techniques were used to assess and evaluate surface morphology. The DFT-based analysis indicates that aromatic rings played a significant role in the charge sharing (donation and acceptance) in [BzMImBr].

Highly efficient green corrosion inhibitor for mild steel in sulfuric acid: Experimental and DFT approach

Chemical corrosion inhibitors are commonly used for protecting the metallic surface from corrosion. But these chemical inhibitors pollute the environment and make the residual water unfit for use. In contrast, green corrosion inhibitors (GCI) i.e., plants and their products are environment-friendly in nature and contribute towards sustainable developments. Petals of B. glabra were investigated as GCI for mild steel at different concentrations and temperatures by polarization, impedance spectroscopy, and gravimetric methods. SEM and metallurgical microscopy were used for the surface studies. Henry and Langmuir adsorption isotherms were used for adsorption studies. A computational (DFT) study was performed to augment experimental data. B. glabra shows 93.13 ± 0.02% corrosion inhibition efficiency for mild steel in 1.0 M H2SO4. The thermodynamic, kinetic, and DFT studies of the inhibitor/mild steel interface help in understanding the adsorption and corrosion mechanism. A relation between inhibition efficiency obtained from theoretical and experimental techniques was established. Waste water was analyzed for its biochemical assay after gravimetric studies, and was found within permissible limits. B. glabra extract was proved to be an effective GCI for protecting mild steel from acid corrosion and hence contribute towards sustainable developments by using natural material (plants and their products) without polluting the environment.

Temperature Effects on the Corrosion Inhibition of Mild Steel in Sulfuric Acid Solution by Acacia senegal Gum with Halide Ions

The effects of temperature on the inhibitive effect of naturally occurring Acacia senegal gum exudate on the corrosion of mild steel in sulfuric acid was studied between 35 and 70 °C using electrochemical impedance spectroscopy and potentiodynamic polarization methods. Findings showed that Acacia senegal gum exudate decreases the corrosion rate of mild steel. The inhibition efficiency declined with raising temperature above 35 °C. The increase in the corrosion rate with increasing temperature was observed for both uninhibited and inhibited systems. Addition of halide ions to the Acacia senegal gum exudate solution enhanced the corrosion inhibition efficiency because of synergistic effects, achieving higher performance with iodide ions as compared to bromide ions. However, the synergistic effects declined above 35 °C up to 70 °C due to temperature effects. It has been observed that increasing temperature adversely affected inhibition efficiencies of both Acacia senegal gum exudate and the synergy between Acacia senegal gum exudate and halide ions. Corrosion rates of mild steel, inhibition efficiencies of Acacia senegal gum exudate and the synergistic effects of halide ions from polarization and impedance measurements were consistent.
 Keywords: temperature, corrosion, mild steel, synergistic effects, Acacia senegal, gum exudate.

Decyltriphenylphosphonium bromide containing hydrophobic alkyl-chain as a potential corrosion inhibitor for mild steel in sulfuric acid: Theoretical and experimental studies

A triphenylphosphonium based ionic liquid containing a long hydrophobic alkyl-chain (designated as DTPPB) was evaluated as a potential corrosion inhibitor for mild steel (MS) in 0.5 M H2SO4 solution. Inhibition efficiency and adsorption behavior of DTPPB was determined by performing the experimental analyses were carried out at the different concentration and temperature. Corrosion inhibition effectiveness of DTPPB was determined experimentally using electrochemical and surface analyses (SEM-EDX and AFM). Polarization studies showed that DTPPB acted as a mixed-type inhibitor. Inhibition effectiveness of DTPPB increases with increasing its concentration. The potentiostatic polarization study revealed that passivation was perceived at lower DTPPB concentrations. The Nyquist plot of impedance is expressed mainly as a depressed capacitive loop with different concentrations. Self-organization of the chains and tail groups to form a coherent hydrophobic film that serves as a barrier for the transport of water, oxygen, and corrosive ions to the metal surface. In addition to the electrochemical studies, surface morphology analyses provided strong evidence for the existence of inhibitor film over the MS surface and their results were supported by the computational data.

Improvement of the corrosion resistance of mild steel in sulfuric acid by new organic-inorganic hybrids of Benzimidazole-Pyrophosphate: Facile synthesis, characterization, experimental and theoretical calculations (DFT and MC)

In this work, a new generation of corrosion inhibitors composed of xMCl2-yNa4P2O7 (MCl2 = 2,2’-dibenzimidazolyl butane dichlorhydrates) hybrids materials have been synthesized successfully with five molar ratios (R1, R2, R3, R4, and R5) by soft chemistry route and characterized. The synthesis was performed in aqueous solutions by the ionic exchange between the pyrophosphate anions and the 2,2′-dibenzimidazolyl butane dichlorhydrates cations. The structure and morphology of the synthesized hybrids are studied by infrared spectroscopy (FT-IR), UV–Visible analysis (UV-vis), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The infrared results show the formation of a new band N-O-P confirming the hybrid structure. The crystalline structure was improved after adding pyrophosphate, confirming the phosphate nucleation and a better settlement of the crystals. These crystals were clearly shown in the SEM images. The corrosion inhibition performance of the prepared compounds were studied on mild steel in 0.5 M sulfuric acid by electrochemical impedance spectroscopy (EIS) and polarization studies. The inhibition efficiency increased with increasing inhibitor concentration, while the corrosion current density decreased. Indeed, the best inhibitor of these hybrids is R1 with an inhibition power of 97.1 % at 300 ppm. The effect of temperature on inhibitory efficiency in a range of 298 to 328K is discussed. The SEM images are also confirmed that the R1 retards the corrosion on the mild steel surface. The EDX analysis presented that this surface is mainly composed of N and P elements. The theoretical calculation results show that the benzimidazole cycle and the heteroatoms of N, O and P are the active sites of inhibitor R1.

Corrosion Inhibition of Mild Steel in Sulfuric Acid by a Newly Synthesized Schiff Base: An Electrochemical, DFT, and Monte Carlo Simulation Study

AbstractEffects of using a synthesized aminothiazole (BZ) Schiff base at different concentrations with and without the addition of 1 mM of KI on the corrosion mitigation of mild steel (MS) in 0.5 M sulphuric acid (H2SO4) solutions are studied electrochemically using direct and alternating currents (DC and AC) techniques. Besides, the adsorption and thermodynamic parameters are calculated in a temperature range of 293–323 K. Furthermore, Mott‐Schottky analysis is used to study the type of oxide layer on the MS surface. Quantum chemical calculations and Monte Carlo simulation techniques are used, and both confirmed the experimental results.

Novel Green Corrosion Inhibitor for Mild Steel in Sulfuric Acid

Salix leaves water extract was studied for the corrosion inhibition of mild steel in H2SO4 at different temperatures. Energy dispersive spectroscopy (EDX), Gas Chromatography Mass spectrometry (GC–MS), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used in our investigation. By applying different techniques as potentiodynamic polarization and electrochemical impedance to detect the effect of the Salix active ingredients onto the mild steel in acidic medium, it was confirmed that the corrosion process was inhibited. Salix water extract acts by decreasing the available cathodic and anodic reaction area. The adsorption isotherm has revealed that the inhibitor adsorbed on the metal surface obeys Langmuir and Temkin isotherm.

The Surface Coverage and Corrosive Rate of Methanol Extract from Taro Tuber (Colocasia esculenta) on Mild Steel in Sulfuric Acid

Surface coverage and corrosion rate of taro tuber methanol extract on mild steel in dilute 0.5 M sulfuric acid solution were studied through weight loss method, FT-IR spectroscopy and SEM.The result obtained in 0.5 M sulfuric acid solution for 72 hours with optimal surface coveragewas 0.86. The corrosion ratewas found to be decreased and surface coveragewas increased with the increasing concentration of taro tuber methanol extract which was added. The results showed that taro tuber methanol extract was a good corrosion inhibitor.

Increase corrosion resistance of mild steel in sulfuric acid and hydrochloric acid solutions by metoclopramide tablet

AbstractIn this article, metoclopramide tablet was thoroughly evaluated as an effective inhibitor for mild steel in 0.5 M sulfuric acid and 1 M hydrochloric acid solutions by different techniques (potentiodynamic polarization and electrochemical impedance spectroscopy [EIS]) and scanning electronic microscopy (SEM). The results revealed that the compound has a proper inhibiting effect at concentrations of 600 ppm for sulfuric acid and 300 ppm for hydrochloric acid solutions. The effect of temperature on the corrosion rate of alloy in the absence and presence of this drug was also studied. The EIS measurements revealed that by the addition of the inhibitor up to a certain concentration, the charge transfer resistance increases and the double layer capacitance decreases. The probe showed that the adsorption of the inhibitor on the alloy surface in both solutions follows Langmuir adsorption isotherm. This process is spontaneous and exothermic. The information obtained from SEM confirmed the formation of the protective layer on the surface of the sample after immersion in solutions containing the compound.

Pongamia Pinnata as a Green Corrosion Inhibitor for Mild Steel in 1N Sulfuric Acid Medium

Due to the harmful nature of the traditional inhibitors, in recent years researchers have an interest in using eco-friendly corrosion inhibitors. The plant extracts exhibit efficient corrosion inhibition properties due to the presence of a mixture of organic constituents starting from terpenoids to flavonoids. In the present study the inhibition of corrosion of mild steel in 1N H2SO4 solution using the leaf extract of Pongamia pinnata (P. pinnata) was investigated by the weight loss method, potentiodynamic polarization method and electrochemical impedance spectroscopy (EIS) technique. Characterization of the leaf extract of P. pinnata was carried out using Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GCMS) analysis. The effect of temperature and immersion time on the corrosion behavior of mild steel in sulfuric acid with different concentrations of P. pinnata was also studied. From the results it was found that the inhibition is mainly attributed to the adsorption of inhibitor molecules on the mild steel electrode surface. It was found that the adsorption of inhibitor molecules takes place according to the Langmuir, Temkin, and Freundlich adsorption isotherms. Kinetic as well as thermodynamic parameters were calculated, also confirming the strong interaction between inhibitor molecules and the electrode surface. The inhibition efficiency (I.E in %) was found to increase with increase in concentration of the inhibitor molecules and the maximum inhibition efficiency was attained at 100 ppm of the leaf extract. From the electrochemical studies it was found that the corrosion process was controlled by a mixed inhibition process and single charge transfer mechanism. Fourier transform infrared spectroscopy (FTIR) provided the confirmatory evidence for the adsorption of the extract molecules on the mild steel surface, which is responsible for the corrosion inhibition. Scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX) experiments also confirmed the presence of inhibitor molecules on the mild steel surface. From all these experimental results, it can be concluded that the leaf extract of P. pinnata acted as a good corrosion inhibitor for mild steel in 1N sulfuric acid medium even at lower inhibitor concentrations.

Aster koraiensis as nontoxic corrosion inhibitor for mild steel in sulfuric acid

Abstract Inhibition efficiency of Aster koraiensis leaf extract toward corrosion of mild steel in 1 M H2SO4 solution was investigated using weight loss, electrochemical, FT-IR, SEM, and EDX methods The individual phenolic compounds present in A. koraiensis extract were identified. Maximum efficiency of 90.53% was achieved at 2000 ppm of the extract. The corrosion kinetic parameters determined from the polarization curves indicated that the extract acted as a mixed-type inhibitor. Adsorption of the inhibitor on the mild steel surface obeyed the Langmuir isotherm. SEM investigations confirmed the formation of inhibition layer unto the metal surface by compounds present in the extract.

Citrus aurantium leaves extracts as a sustainable corrosion inhibitor of mild steel in sulfuric acid

Corrosion inhibition of mild steel in 1 M H2SO4 was investigated in absence and presence of Citrus aurantium leaves extracts as a friendly inhibitor. The effect of temperature, time, and inhibitor concentration were studied using weight loss technique. The result obtained revealed that Citrus aurantium leaves extracts act as an inhibitor for mild steel in H2SO4 and reduces the corrosion rate. The inhibition efficiency was found to increases with increase in inhibitor concentration whereas the temperature shows otherwise. Higher inhibition efficiency was 89% at 40 °C and 10 ml/l inhibitor concentration. The adsorption of Citrus aurantium leaves extracts was found to follow Langmuir adsorption isotherm model. The values of the free energy of adsorption was around −20 kJ/mol, which is indicative of physical adsorption between charged molecules and a charged metal. Quantum chemical calculations were also used as a theoretical support to the experimental results. Finally the scanning electron microscope and Fourier transform infrared spectroscopy were evaluated to examine surface morphology and molecular structure of inhibitor respectively.

Experimental evaluation of quinolinium and isoquinolinium derivatives as corrosion inhibitors of mild steel in 0.5 M H2SO4 solution

The 1-methylquinolinium iodide (I) Qui+, I– and 2-methylisoquinolinium iodide isoQui+, I– were investigated as a corrosion inhibitors for mild steel in sulfuric acid using electrochemical impedance spectroscopy and potentiodynamic polarization techniques. The results indicated that the corrosion inhibition efficiency and extent of surface coverage were increased with increase in inhibitors concentrations. Polarization curves revealed that both inhibitors acted as a mixed-type inhibitor. The thermodynamic parameters were evaluated for corrosion inhibition process. The adsorption of both inhibitors on mild steel surface obeyed Langmuir adsorption isotherm.

Salvia Hispanica as Eco-Friendly Inhibitor for Mild Steel in Sulfuric Acid

Salvia hispánica seeds extract has been investigated as a carbon Steel corrosion inhibitor in 0.5 M sulfuric acid by using polarization curves, electrochemical impedance spectroscopy, electrochemical noise and weight-loss, tests at different concentrations (0, 100, 200, 400, 600, 800 and 1000 ppm) and temperatures, namely 25, 40 and 60 °C. Results show that inhibition efficiency increases as the inhibitor concentration increases, decreases with temperature. The extract inhibit corrosion mainly by an adsorption mechanism. Potentiodynamic polarization studies show that extract is mixed-type inhibitors.

Inhibition of acid corrosion of mild steel by Anacyclus pyrethrum L. extracts

Inhibition of the corrosion of mild steel in sulfuric acid by extracts of Anacyclus pyrethrum L. (leaves and stems, AP-LS; flowers AP-F; roots, AP-R) has been studied by use of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. Anacyclus pyrethrum L. inhibited the corrosion of mild steel in 0.5 M H2SO4 solution. Polarization curves show that the different parts of plants act as anodic type inhibitors. Changes in impedance data (charge transfer resistance, Rt, and double layer capacitance, Cdl) were indicative of adsorption of the extracts on the metal surface, leading to the formation of protective films. The extent of surface coverage by the inhibitors was determined by measurement of ac impedance; it was found that adsorption of these inhibitors on the mild steel surface obeys the Langmuir adsorption isotherm. Activation energies in the presence and absence of AP-LS and AP-F were obtained by measuring the temperature dependence of the corrosion current.

Corrosion Protection Properties of 4-[(E)-[(2,4-Dihydroxy phenyl)methylidene] amino]-6-methyl-3-sulfanylidene-2,3,4,5-tetrahydro-1,2,4-triazin-5-one [DMSTT] Toward Mild Steel in Sulfuric Acid

The inhibition of mild steel corrosion in aerated 0.5 N H2SO4 solution was investigated using potentiodynamic polarization studies (Tafel), linear polarization studies, electrochemical impedance spectroscopy studies, adsorption studies, and surface morphological studies. The effect of inhibitor concentration on corrosion rate, the effect of temperature, degree of surface coverage, adsorption kinetics, and surface morphology are investigated. The inhibition efficiency increased markedly with increase in the additive concentration and decreased slightly with increasing temperature. The presence of DMSTT decrease the double-layer capacitance and increase the charge transfer resistance. The value of activation energy (Ea) of metal corrosion, adsorption equilibrium constant (Kads), and free energy of adsorption (ΔGads) were calculated from the temperature dependence of corrosion current. The adsorption of inhibitor molecule on mild steel surface follow Langmuir isotherm. DMSTT offers excellent inhibition properties and acts as a mixed-type inhibitor.

Electrochemical Measurements of Corrosion Inhibition of Mild Steel in Sulfuric Acid by BIMGCS12-3

Gemini benzimidazole cationic surfactant, propanediyl-α, ω-bis-(N-dodecyl benzimidazole ammonium bromide), referred as BIMGCS12-3, was synthesized from the raw materials of benzimidazole, dodecane bromide and dibromopropane. The structure of the target compound was confirmed by HNMR and elemental analysis. Electrochemical behaviors of BIMGCS12-3 for protecting mild steel from sulfuric acid corrosion were issued. Changes in impedance parameters (charge transfer resistance, Rct, and double layer capacitance, Cdl) were indicative of the feasibility of BIMGCS12-3 as excellent mild steel corrosion inhibitor in sulfuric acid.

Raphia hookeri gum as a potential eco-friendly inhibitor for mild steel in sulfuric acid

Exudate gum from Raphia hookeri (RH) was tested as corrosion inhibitor for mild steel in H2SO4 using weight loss and hydrogen evolution techniques at 30–60 °C. Results obtained revealed that RH act as corrosion inhibitor for mild steel in sulfuric acid medium. The corrosion rates in all concentrations studied increased with rise in temperature. The inhibition efficiency was observed to increase with increase in RH concentration but decreased with rise in temperature, which is suggestive of physical adsorption mechanism. The inhibitive action of RH is discussed in view of the adsorption of its phytochemical components onto steel surface, which protects the metal surface and thus do not permit the corrosion process to take place. The adsorption of the exudate gum onto the steel surface was found to follow the Langmuir adsorption isotherm. The free energies for the adsorption process and the apparent activation energies, enthalpies and entropies of the dissolution process were determined. The fundamental thermodynamic functions were used to glean important information about the RH inhibitory behavior. The results were explained in terms of chemical thermodynamics.

1-Phenacylmethyl-2-(acylaminothiocarbonylamino)pyridinium bromides as protectors of steel acid corrosion

Inhibiting effect of 1-phenacylmethylpyridinium bromides containing acylthiourea substituents in the pyridine ring on corrosion of mild steel in sulfuric acid (3 M) was studied.