Corrosion Inhibition Capabilities Research Articles

The behavior of two indazole derivatives on the copper/sulfuric acid interface in terms of adsorption and corrosion inhibition

BackgroundTo reduce the degree of copper corrosion by the pickling solution, the introduction of organic inhibitors into the pickling solution is a reasonably effective measure.5-fluoro-1H-indazole (5-FIA) and 5‑chloro-1H-indazole (5-CIA) may act as exceptional inhibitors. MethodsBased on experimental and theoretical methods, the antiseptic ability of two indazole derivatives on copper in sulfuric acid was researched. Significant findsThe results of electrochemical experiments show that in the test solution containing 1 mM inhibitors, the corrosion inhibition efficiency (η) of 5-FIA and 5-CIA was 90.4% and 94.3%, respectively, indicating that 5-FIA and 5-CIA have outstanding corrosion inhibition capabilities and their antiseptic effects are in the order of 5-FIA < 5-CIA, which is also confirmed by observations of Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Furthermore, both 5-FIA and 5-CIA are mixed-type inhibitors and their adsorption behavior follows Langmuir isothermal adsorption model. The results of X-ray Photoelectron Spectroscopy (XPS), theoretical calculations, and molecular dynamics simulations further reveal the mechanism that 5-CIA has stronger adsorption capacity than 5-FIA.

Graphene/Waterborne Epoxy Coatings with Dual Functionalities of Barrier and Corrosion Inhibitor

A facile and environmentally-friendly method is developed to prepare graphene/waterborne epoxy (WEP) composite coatings. The graphene nanosheets are produced with electrochemical-exfoliation in the solution containing surfactants, cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS). The nanosheets containing solution thus formed is subjected to a quick dialysis and then directly used as a diluent for WEP without any further treatment. This preparation method overcomes the commonly identified problems of aggregations and ‘corrosion promotion’ effect associated with graphene, and increases the impedance of the composite coatings by more than two orders of magnitude. The analysis of anticorrosion performance suggested that the presence of surfactants not only improves the dispersibility of graphene nanosheets but also endows the composite coatings with both barrier and corrosion inhibition capabilities. The strategy reported herein may pave the path to the large-scale production of the graphene anticorrosion coatings. Figure 1

Electrochemical and computational estimations of cephalosporin drugs as eco-friendly and efficient corrosion inhibitors for aluminum in alkaline solution

In this study, the anionic state of Ceftriaxone sodium (Cefx) and Ceftazidime (Cefz) medication corrosion inhibition capabilities for Al in 0.1 M NaOH solution are explored using various electrochemical analyses. Furthermore, the morphological structure and surface chemical composition of the impact of these drugs on the Al substrate in NaOH are investigated. For the prediction and analysis of interactions between molecule structure and inhibition efficiency, quantum chemical calculations (QC), Monte Carlo simulations (MC), and molecular dynamics (MD) simulations (MD) are performed. The electrochemical findings reveal that the inhibitory effectiveness increases with increasing drug concentrations and declines with rising temperature, reaching a maximum value of 78.4% for 300 ppm Cefx while 59.5% for 300 ppm Cefz at 293 K, implying that Cefx outperforms for Cefz. In addition, the studied drugs act as cathodic inhibitors, and their adsorption is spontaneous and mixed type adsorption in its nature that obeys Freundlich isotherm for Cefz while Temkin isotherm is the best-fitted one for Cefx. Surface analysis and wettability measurements imply that Cefx and Cefz shield the Al against corrosion by surface adsorption and generating a protective hydrophobic film. Thermodynamic activation parameters in the absence and presence of 300 ppm of the studied drugs are calculated and discussed. The energies of the border molecular orbitals and computed molecular parameters for the investigated drugs revealed that anionic Cefx is more readily adsorbed on the Al surface than Cefz. This finding is validated further using MC and MD simulations. Overall, the proposed cephalosporin drugs delivered a cost-effective and facile approach for boosting the efficiency of corrosion inhibitors for Al under aggressive conditions.

A facile approach to fabricating graphene/waterborne epoxy coatings with dual functionalities of barrier and corrosion inhibitor

• A facile approach to fabricating C-G/WEP and S-G/WEP composite coatings with dual functionalities as barriers and corrosion inhibitors was developed. • The impedance of the C-G/WEP and S-G/WEP coatings is enhanced by more than two orders of magnitude compared with that of WEP coatings. • The presence of surfactants facilitates the dispersion of C-G and S-G nanosheets in both the solution and the composite coatings. • The surfactants endow inhibition ability of the coatings, thereby the composite coatings effectively protect the underlying Q235 steel against corrosion. • This work exemplifies a facile yet environmentally-friendly approach to preparing graphene composite coatings and may enable the large-scale production of graphene anticorrosion coatings. A facile and environmentally-friendly method is developed to prepare graphene/waterborne epoxy (WEP) composite coatings. The graphene nanosheets are produced with electrochemical-exfoliation in the solution containing surfactants, cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS). The nanosheets containing solution thus formed are subjected to a quick dialysis and then directly used as a diluent for WEP without any further treatment. This preparation method overcomes the commonly identified problems of aggregations and ‘corrosion promotion’ effect associated with graphene, and increases the impedance of the composite coatings by more than two orders of magnitude. The analysis of anticorrosion performance suggested that the presence of surfactants not only improves the dispersibility of graphene nanosheets but also endows the composite coatings with both barrier and corrosion inhibition capabilities. The strategy reported herein may pave the path to the large-scale production of graphene anticorrosion coatings.

Experimental and theoretical evaluations on Oleuropein as a natural origin corrosion inhibitor for copper in acidic environment

Copper corrosion in acidic cleaning solutions is a major worry for heat exchangers. Corrosion inhibitors derived from natural sources might be a viable option. The isolation of Oleuropein compound from olive leaf and investigation of its anticorrosion potential for copper in 1.0 M H2SO4 solution are reported here. All experimental results from LC–MS, FT-IR, 1H and 13C-NMR characterizations support the molecular structure of Oleuropein. Electrochemical and gravimetric tests were used to evaluate the corrosion inhibition capabilities of Oleuropein. According to polarization investigation, Oleuropein is a mixed-type inhibitor. Oleuropein's inhibitory efficacy increases with concentration, attaining an optimum value (98.92%) at 100 mg L−1. At high temperatures, Oleuropein can be considered an efficient inhibitor. Thermodynamic variables for the activation operation and copper dissolution were computed and addressed as well. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) examinations revealed that Oleuropein produced an outer layer on the copper surface, shielding it from severe acid damage. Quantum chemical simulations were employed to propose molecular explanations for Oleuropein's inhibitory actions.

Mechanistic evaluation of adsorption and corrosion inhibition capabilities of novel indoline compounds for oil well/tubing steel in 15% HCl

• The studied compounds competent corrosion inhibitors for N80 steel in 15% HCl. • The inhibition efficiency remains nearly constant at elevated temperatures. • The Langmuir isotherm confirms chemisorption of the studied corrosion inhibitors. • Generation of an organic–inorganic hybrid film protect the metal from corrosion. The investigation presents the superior corrosion inhibition capabilities of two novel indoline compounds namely 2-(1-(4-((furan-2-ylmethylene)amino)-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)-2-(1H-imidazol-2-yl)ethyl)isoindoline-1,3-dione (FTTI) and 2-(1-(4-((furan-2-ylmethylene)amino)-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)-2-methylbutyl)isoindoline-1,3-dione (FTMI) for oil well/ tubing steel in 15% HCl solution. The gravimetric studies confirm corrosion inhibition efficiency of 99.08% and 97.75% respectively at 303 K for significant low dosage of 50 μML -1 . The corrosion inhibition efficiency remained nearly constant at elevated temperatures due to predominant chemisorption of the inhibitors upon the metallic substrate. The chemisorption of the compounds is confirmed by the values of free energy of adsorption (Δ G ads ), which lie within the range of −47.60 kJmol −1 to −55.42 kJ mol −1 for FTTI and −45.95 kJmol −1 to −54.34 kJmol −1 for FTMI. The electrochemical analysis approves that the reduction in cathodic corrosion reaction (metal dissolution) occur through inhibitor adsorption upon the active sites; while the anodic reaction (hydrogen evolution reaction) is reduced due to thickening of the double layer at the metal solution interface. The substrate surface analysis through SEM, AFM, EDX and XPS reveal that the inhibitors generate an organic–inorganic hybrid protective film to protect the surface form aggressive acid solution. The theoretical studies through DFT and MDS justifies the experimentally obtained corrosion parameters and supports the superior corrosion inhibition capacity of FTTI over FTMI

Insight on the corrosion inhibition performance of psidium guajava linn leaves extract

This work multi-angle explored the anti-corrosion nature and mechanism of psidium guajava linn leaves extract for copper in H2SO4 environment.In this study, we used a simple and eco-friendly extraction way to acquire psidium guajava linn leaves extract (PGLLE). Fourier Transform infrared spectroscopy (FTIR) was executed to determine the active functional groups in PGLLE. Quantum chemical calculations effectively forecast the anti-corrosion characteristic of the four active substances in PGLLE. The results of molecular dynamics simulation predicted the stabilized adsorption configurations of the four substances in PGLLE on the Cu (111). Surface topography analysis can intuitively demonstrate that PGLLE effectually inhibits Cu corrosion. The data of electrochemical experiments show that the anti-corrosion capacity of PGLLE increases with the increase of the concentration in a certain interval. As the temperature hoists at definite temperature range, PGLLE can still be efficaciously adsorbed at the Cu surface, showing high-quality corrosion inhibition capabilities. Psidium guajava linn leaves can exist widely in nature, so it has great economic value as the inhibitor. Besides, PGLLE basically does not pollute the ecosystem when used as inhibitors.

Corrosion protection of petroleum oil well/tubing steel using thiadiazolines as efficient corrosion inhibitor: Experimental and theoretical investigation

Present investigation measures corrosion inhibition capabilities of thiadiazoline compounds; DFAT [2-4(difuran-2-yl-3-azabicyclo[3.3.1] nonan-9-yl-)-5-spiro-4-acetyl-2-acetylamino-1,3,4-thiadiazoline] and DIAT [2-4(di-1H indole-3-yl-3-azabicyclo[3.3.1]nonan-9-yl-)-5-spiro-4-acetyl-2-acetylamino-1,3,4-thiadiazoline] for petroleum oil well/tubing steel (N80 steel) in 15% HCl with the help of different techniques. The studied organic compounds show excellent corrosion mitigation properties with highest efficiency of 96.02% for DFAT and 97.05% for DIAT at a very small dosage of 50 ppm and 303 K temperature. Adsorption of both inhibitor molecules on the surface of N80 steel obeyed Langmuir adsorption isotherm. Potentiodynamic polarization studies revealed that both the compounds act as mixed type corrosion inhibitor and adsorb at the cathodic as well as anodic sites to mitigate corrosion process. The surface study was done through SEM, EDX, AFM, FT-IR and XPS analysis. The theoretical analysis (DFT and Monte Carlo simulations) of both inhibitors correlates the experimental findings.

Mitigation of corrosion in petroleum oil well/tubing steel using pyrimidines as efficient corrosion inhibitor: Experimental and theoretical investigation

Present investigation focused on to study the corrosion inhibition capabilities of pyrimidine derivatives; MPA [4,6-bis(4-methoxyphenyl) pyrimidin-2-amine] and CPA [4,6-bis(4-chlorophenyl) pyrimidin-2-amine] for oil well/tubing steel (N80 steel) in 15 % HCl solution. Corrosion inhibition efficiency of both inhibitors increases on increasing the concentration and decreases on increasing the temperature. The studied organic compounds show excellent corrosion mitigation properties with highest efficiency of 99.5 % for MPA and 94.7 % for CPA at a considerably low dosage of 250 μM L−1. Adsorption of both inhibitors obeyed Langmuir adsorption isotherm and nature of adsorption is mixed type adsorption. Potentiodynamic polarization studies showed that both the compounds adsorb at the cathodic and anodic sites of the substrate surface to mitigate corrosion process and both inhibitors act as mixed type corrosion inhibitor. The surface study uninhibited and inhibited sample was done through SEM, EDX, AFM, FT-IR and XPS analysis and suggested the formation of protective layer of inhibitor molecules on the N80 steel surface to mitigate its corrosion. The theoretical analysis (DFT and Monte Carlo simulations) of both inhibitors correlates the experimental findings.

Evaluation of corrosion inhibition and self healing capabilities of nanoclay and tung oil microencapsulated epoxy coatings on rebars in concrete

Corrosion of civil infrastructure is the biggest challenge faced by the construction industry worldwide and billions of dollars are spent for its repair and rehabilitation. One of the methods to mitigate the effects of corrosion is the use of Epoxy Coated Rebars (ECR) in concrete. But epoxy coatings are inherently brittle and susceptible to crack initiation and propagation. Thus, to further improve their efficiency in inhibiting corrosion, modifications in the epoxy coatings have to be done. In the present study, it is suggested to modify epoxy coatings by adding nano-clay and tung oil microcapsules. To measure the effectiveness of these coatings to corrosion inhibition, non-destructive monitoring has been done using electrochemical current measurements and ultrasonic guided wave propagation characteristics while the coated rebars are subjected to impressed current accelerated corrosion. The corrosion introduces non-uniform and localized pits in the rebars and disturbs the path of the propagating guided waves through it by mode conversions and scattering which results in drop in transmitted guided wave signal strengths. Nano dispersion of clay in epoxy not only increase of toughness, tensile and flexural properties of the epoxy but leads to torturing of the path for moisture progression. Lastly, the hydrophobic nature of modified clays will aid in reducing progression of water molecules. This was successfully illustrated by very small corrosion current values and small rate of drop in ultrasonic guided wave voltage signals as compared to plain epoxy coated rebars. On the other hand, tung oil microcapsules in Urea-formaldehyde (UF) shells prepared by in-situ polymerization improves the self-healing ability and adhesion strength of capsule embedded coatings and act as self-healing agents. Tung-oil micro-encapsulated coatings perform the best in terms to corrosion resistance as well as bonding with surrounding concrete. The drop in voltage amplitudes as well as the rate of voltage drop with increasing corrosion exposure is very nominal and insignificant. It points towards remarkable inhibition of corrosion offered by self-healing tung oil microcapsules to corrosion damage.

Electrodissolution Inhibition of Gold Nanorods with Oxoanions

Metal nanoparticles experience varied chemical environments that can cause corrosion and dissolution in electronics, electrocatalysis, and sensing applications. Understanding oxidative dissolution is critical for plasmonic nanoparticles because their optical properties strongly depend on size and shape. We demonstrate that the addition of low relative concentrations of oxoanions to aqueous halide electrolyte solutions improves the morphological stability of plasmonic gold nanorods at anodic electrochemical potentials that otherwise induce complete oxidative electrodissolution. Single particle hyperspectral dark-field imaging and correlated scanning electron microscopy show that oxoanions alter the electrodissolution onset potential, electrodissolution pathway, and nanoparticle reaction heterogeneity, as compared to chloride-only electrolyte solutions. We identify five mechanistic contributors to the corrosion inhibition capabilities of oxoanions in the presence of chloride ions, with the aim of expanding ...

Steel corrosion in magnesia–phosphate cement concrete beams

The acoustic emission (AE) technique was employed to investigate the corrosion-induced deterioration of steel-reinforced magnesia–phosphate cement (MPC) concrete beams under the coupling effect of loading and accelerated chloride diffusion. A cement-based piezoelectric sensor was used for AE detection owing to its high sensitivity and good compatibility with the concrete matrix. Power spectral density analysis and continuous wavelet transform were used to process the detected AE signals. It was found that the average frequency shift was closely related to the damage accumulation level in the reinforced MPC concrete beams. Based on the frequency characteristics of the detected AE signals during wet–dry cycles, the corrosion-induced degradation process of MPC beams was divided into three stages, from micro-cracking to localised macro-crack propagation. Wavelet analysis revealed the energy density distribution of the AE waveform, which was used to differentiate signal features between reinforcement corrosion and concrete cracking. In addition, comparisons in terms of the accumulated AE event number and half-cell potentials showed that MPC and OPC concrete had comparable corrosion inhibition capabilities.

Smart epoxy coating containing Ce-MCM-22 zeolites for corrosion protection of Mg-Li alloy

The epoxy coatings containing MCM-22 and Ce-MCM-22 zeolites were prepared by coating method on the Mg-Li alloy surface. The influence of MCM-22 and Ce-MCM-22 zeolites on corrosion protection of the epoxy coating was studied. The epoxy coating containing Ce-MCM-22 zeolites showed high corrosion resistance. Artificial defects in the epoxy coating containing Ce-MCM-22 zeolites on the Mg-Li surface were produced by the needle punching. The results show that the epoxy coating containing Ce-MCM-22 zeolites exhibits self-healing corrosion inhibition capabilities. It is ascribed to the fact that the Ce3+ ions are released from MCM-22 zeolites based on ion exchange of zeolite in the corrosion process of the Mg-Li alloy substrate. MCM-22 zeolites as reservoirs provided a prolonged release of cerium ions.

Corrosion Inhibition Performance of Triazole Derivatives on Copper-Nickel Alloy in 3.5 wt.% NaCl Solution

This study investigates the performance of three triazole derivatives with different molecular structures as corrosion inhibitors for the copper-nickel alloy CuNi 90/10 in 3.5 wt.% NaCl solution. Inhibition behavior was systematically determined through electrochemical measurements, scanning electron microscopy, energy-dispersive spectroscopy, and Fourier transform infrared spectroscopy. In addition, adsorption behavior and the inhibition mechanism were investigated via quantum chemical calculation and molecular dynamic simulation. Experimental results indicate that the three inhibitors with triazole rings and heteroatoms exhibited excellent corrosion inhibition capabilities on the copper-nickel alloy surface through physisorption and chemisorption. In particular, 3-amino-5-mercapto-1,2,4-triazole showed the best inhibition capability according to the concentration ranges considered in the experiments. The results of quantum chemical calculation agreed with the experimental findings.

Ionic liquids [EMIM][BF4], [EMIM][Otf] and [BMIM][Otf] as corrosion inhibitors for CO2 capture applications

We present the viability of using thermally stable, practically non-volatile ionic liquids as corrosion inhibitors in aqueous monoethanolamine systems. Carbon steel 1020, which is widely used as a construction material in CO2 capture plants, has been taken as a test material. Corrosion inhibition capabilities of typical room-temperature ionic liquids constituting imidazolium cation in concentration range ≤3% in CO2 capture applications were investigated. Electrochemical corrosion experiments using the potentiodynamic polarization technique for measuring corrosion current were carried out. Subsequent calculation of corrosion rate via Tafel fit was performed. The experimental findings suggest that the corrosion rate is significantly dependent on the process parameters, such as the CO2 loading and the presence of oxygen. In addition, the value of the corrosion rate is sensitive to the type of ionic liquid added. Moreover, the results show that ionic liquids possess the ability of suppressing severe operational problems of corrosion in typical CO2 capture plants to a reasonable extent (≥50%).

4(5)-Methylbenzotriazole: a review of the life-cycle of an emerging contaminant

4(5)-Methylbenzotriazole (MeBT), also known as tolyltriazole is a widely used compound that effectively prevents the corrosion of many metals in acidic and saline aqueous solutions. This review summarizes the current body of knowledge related to MeBT including its uses, corrosion inhibition capabilities, chemical and toxicological properties, occurrence in the environment, and treatment and removal from water supplies. Key conclusions include: poor biodegradability of the 5-MeBT isomer and the recalcitrance of the 4-MeBT isomer leading to persistence in the environment, poor removal efficiencies in conventional water treatment facilities, and the generally unknown chronic effects of MeBT. The aim of this paper is to bring to light the relevant facts about MeBT in a concise manner so that we may make more informed decisions regarding its use and of the potential long-term environmental effects that it may cause.

A correlation between Malva sylvestris extracts molecules and their corrosion inhibition capabilities

Experimental and quantum chemical investigations have been coupled in order to determine anticorrosion potential of Malva sylvestris extract molecules. The plant extract is a mixture of chemicals of which only four are abundant. Two groups of molecules are evidenced using quantum chemical parameters. The electrochemical investigation has classified the plant extract as a mixed-type inhibitor. The %EI has been only 54.5% due to antagonistic effects of the extract molecules.

Superhydrophobic-carbon fibre growth on a zinc surface for corrosion inhibition

A superhydrophobic-carbon fibre (CF) layer with enhanced corrosion inhibition ability was catalytically grown on a Zn surface. Cu, which was produced by a galvanic replacement reaction, acted as a catalyst for CF growth. The contact angle and water repellence properties of the grown materials were measured to determine their superhydrophobicity. The potentiodynamic polarisation technique revealed the corrosion inhibition capabilities of the different materials used. Compared with bare Zn, the superhydrophobic Zn–CF material showed enhanced corrosion inhibition properties. During immersion in NaCl solution, perforations caused by capillary condensation decreased the superhydrophobicity of the materials and limited their corrosion inhibition capabilities.

Characterization of Zr(IV)–Phosphonate Thin Films Which Inhibit O2 Reduction on AA2024-T3

Zr(IV)–alkyl-phosphonate and Zr(IV)–aryl-phosphonate thin films of varying compositions were investigated for corrosion inhibition capabilities on AA2024-T3. A strong correlation between the alkyl chain length and the ability of these self-assembled systems to inhibit the reduction reaction at the alloy surface was found. In particular, modification using Zr(IV)–octadecyl-phosphonate initially inhibits reduction currents by more than 2 orders of magnitude in 0.1 M at a potential of −0.80 V vs a saturated calomel electrode and by greater than 95% after 5500 s under similar conditions. Scanning electrochemical microscopy reveals uniform inhibition of cathodic processes. Auger electron spectroscopy confirms the presence of Zr and P in the thin film. Infrared reflection–absorption spectroscopy indicates that the alkyl chains are in a liquidlike environment. Long-term testing of the Zr(IV)–octadecyl-phosphonate system in a sulfate-containing solution yields low levels of surface activation, as evidenced by small amounts of trenching adjacent to intermetallic particles and little change in near-surface Cu content.

The effects of structural variation in some isoxazolidines on the corrosion inhibition of carbon steel in 0.5 M sulfuric acid

PurposeThe aim is to demonstrate corrosion inhibition capabilities of several isoxazolidines, containing hydrophobic substituents and having varying degree of steric congestion around nitrogen.Design/methodology/approachA number of isoxazolidines were prepared. Corrosion inhibition efficiencies of these organic compounds were determined by gravimetric and electrochemical methods, using carbon steel as the substrate metal and 0.5 M H2SO4 at 40‐70°C as the corrosive environment. Concentration of inhibitor was varied between 5 and 400 ppm.FindingsIncrease in steric congestion around the nitrogen centre and hydrophobic chain lengths as well as increase in temperature (in the presence of the inhibitor in the higher concentration range 100‐400 ppm) were found to increase the corrosion inhibition efficiency of the isoxazolidines. Electrochemical measurements corroborated these results. Thermodynamic parameters (ΔGads0,ΔHads0,ΔSads0) for the adsorption process and kinetic parameters for the metal dissolution (or hydrogen evolution) reaction were determined.Originality/valueThis is the first time the corrosion inhibition characteristics of isoxazolidines, an important class of readily accessible compounds, have been evaluated in H2SO4 medium.