Addition Of Corrosion Inhibitor Research Articles

Folic acid as a green inhibitor for corrosion protection of Q235 carbon steel in 3.5 wt% NaCl solution

AbstractThis study combines experimental and theoretical explorations. The corrosion inhibition performance of different concentrations (50, 100, 250, and 500 ppm) of folic acid in 3.5 wt% NaCl solution on Q235 steel was tested by weight loss and electrochemical test. The corrosion inhibition efficiency increased with the gradual increase of folic acid concentration and reached a maximum of 87% at 500 ppm folic acid. The experimental results for electrochemistry and weight loss are in good agreement with the simulation calculations. The adsorption of folic acid on the steel surface obeyed the Langmuir isotherm, and the adsorption process was a combination of chemisorption and physisorption. The contact angle test also yielded the maximum increase in hydrophobicity of the specimen surface at the added folic acid concentration of 500 ppm. The corrosion morphology after the addition of corrosion inhibitor was relatively flat. The adsorption orientation of folic acid molecules on the steel surface in an aqueous environment was investigated using density functional theory (DFT)/molecular dynamics (MD) simulations. The microscopic mechanism of action of folic acid corrosion inhibitors is clarified.

Highly efficient corrosion inhibitor for low charge voltage and long lifespan rechargeable aqueous zinc-air battery

Hydrogen evolution, passivation and dendrite growth problems faced by zinc anodes of aqueous zinc-air batteries greatly reduce their cycle life and hinder their application in energy storage devices. Herein, a reversible, corrosion-resistant, and long-term stable cycle-life zinc anode is achieved by introducing zinc acetate and zinc gluconate into an alkaline electrolyte as corrosion inhibitors. Zinc acetate adsorbed on the surface of the zinc anode could be able to regulate the anode/electrolyte interface and thus inhibit the growth of dendrites, and zinc gluconate can reduce the charge voltage on the cathode to regulate the oxidation reaction and then prolong the cycle life, which eventually inhibit zinc anode corrosion. The additive package of zinc acetate and zinc gluconate provides a better performance. With addition of corrosion inhibitors, Zn||Cu cells show a high average coulombic efficiency about 94 %, and zinc-air batteries achieve a cycling lifespan of 297 h and low charge voltage of 1.7 V. This work provides a simple but practical guideline for high-performance zinc-air batteries.

Current Overview of Corrosion Inhibition of API Steel in Different Environments.

API (American Petroleum Institute) steels are the most employed metal alloys in the oil industry due to their outstanding mechanical properties; however, their protection is considered as an imperative matter because of their corrosion damage vulnerability when exposed to different surroundings that provoke a rate increase in the concomitant redox reactions. This problematic situation becomes more relevant when the generation and/or use of one or various aqueous corrosive environments occur, in addition to process conditions, the result of which is extremely difficult to be controlled. For these reasons, the internal and external protection of exposed metallic systems are considered as a fundamental concern, where internal corrosion is often controlled through the addition of corrosion inhibitors (CIs). The present review analyzes researchers' contributions in the last years to the study and evaluation of CIs for API steel in different corrosive media featuring HCl, H2SO4, H3NSO3H, CO2, H2S, NaCl, and production water under different temperature and flow conditions. Different CIs derived from plant extracts, drugs, nanoparticles, or ionic liquids, mainly destined for acid media, were found. Throughout the review, an exhaustive analysis of inhibition process results is carried out based on gravimetric and/or electrochemical techniques that consider the weight loss of the metallic material and electrical behavior (current density, resistance, capacitance, frequency, impedance, etc.). Likewise, the results of computational analyses and those of surface analysis techniques were taken into account to reinforce the study of CIs.

The synergistic anti‐corrosion performance and mechanism of meso‐tetra(4‐carboxyphenyl)porphine on steel bars in alkaline environments

AbstractCorrosion protection of steel bars in alkaline concrete environments poses a common challenge in marine engineering. One approach to mitigate steel bar corrosion is the addition of corrosion inhibitors to the concrete. In alkaline environments, the passivation of rebars occurs through anodic passivation coupled with the cathodic oxygen reduction reaction (ORR). The catalysis of ORR can expedite anode passivation. To investigate the corrosion inhibition of steel bars in alkaline environments, meso‐tetra(4‐carboxyphenyl)porphine (TCPP), known for its ORR catalytic properties, is selected. TCPP forms adsorption films on the surface of steel bars, facilitating the formation of passivation films. TCPP primarily adsorbs onto active sites on the surface of the passivation film, where lattice iron ions have leached. The adsorbed TCPP accelerates the formation of the passivation film through ORR catalysis, inhibiting the development of passivation film defects and enhancing the integrity and protection of the passivation film. The most significant effect is observed when the concentration of TCPP is 0.5 mmol/L. The physical adsorption of TCPP is primarily determined by the negative charge centers, namely the carboxyl group O and the pyrrole N. However, due to steric hindrance caused by the unrestricted rotation of the carboxyl benzene, the pyrrole N does not play a dominant role in chemical adsorption. Instead, the active site for chemical adsorption is the carboxyl group O. The adsorption process significantly reduces the diffusion coefficient of TCPP molecules, providing a robust and stable adsorption binding. Phthalocyanine molecules without carboxyl benzene groups adopt a planar structure, allowing them to form stable adsorption configurations on the iron surface through flat adsorption. This observation provides guidance for the design of novel metal phthalocyanine molecules. Specifically, the development of metal phthalocyanine molecules with modifying groups that are coplanar with the phthalocyanine ring and possess restricted rotation can achieve flat adsorption, improve coverage rate, and enhance adsorption configuration stability.

Corrosion behavior of modified cement-based coated steel rebar subjected to different levels of tensile loads

Polymer-modified cement-based coating can provide corrosion protection for steel rebar. However, after the action of the tensile load, the connection between the polymer and the cement matrix was weakened, thus reducing its corrosion resistance. In this study, silica fume, nano-SiO2, and corrosion inhibitor were used to modify EVA (Ethylene Vinyl Acetate Copolymer) and cement-based coatings. Electrochemical experiments were used to evaluate the corrosion behavior of coated steel rebar after the action of different levels of tensile loads, and microscopic characterization and porosity experiments were applied to analyze the changes of microscopic properties of the coatings. The experimental results show that silica fume and nano-SiO2 produce more high-strength C–S–H gels through hydration reaction to improve the tensile properties and compactness of the coating, thus reducing the porosity and chloride ion permeability of the coating after tension. Tetrabasic-modified cement-based coated steel rebar with EVA, silica fume, nano-SiO2, and amino-alcohol corrosion inhibitor displayed the highest coating resistance and the lowest corrosion current density under the action of tensile load. Experimental results proves that nano-SiO2 enhances the tensile properties of the coating. The addition of corrosion inhibitor can further improve the compactness of the coating under tension, hinder the formation of chloride ion transport channel, and adsorb on the surface of steel rebar to improve the corrosion resistance of steel rebar.

High-Loading Smart Carrier Containing 2-Mercaptobenzimidazole-Zn2+-Polydopamine with pH-Responsive Function to Fabricate High-Performance Waterborne Epoxy Anticorrosion Coatings.

Corrosion inhibitor additives are considered to be one of the effective methods to slow down the corrosion of metals, but the corrosion inhibitors will decompose and lose their effect in a long-term corrosive environment. In this work, a smart corrosion inhibitor carrier 2-mercaptobenzimidazole-Zn2+-polydopamine@graphite (MZPG) with excellent pH response was designed and synthesized using a one-pot method. This corrosion inhibitor carrier not only has a very high 2-mercaptobenzimidazole (MBI) loading capacity (38.0%) but also maintains a very low MBI activity to inhibit the decomposition of MZPG in the environment as much as possible. The MZPG/epoxy (MZPG/EP) coatings prepared by the spraying method showed excellent mechanical properties. Electrochemical and salt spray tests showed that the MZPG/EP coatings (1.20 × 1010 Ω·cm2) have excellent corrosion resistance with Rp values up to 3 orders of magnitude higher than that of the EP coating (1.25 × 107 Ω·cm2). Notably, the MZPG/EP coatings maintained good corrosion resistance under acidic conditions due to the pH-responsive release of corrosion inhibitors. This is of great significance for the future development of coatings for highly corrosive environments.

Effect of ionic liquids on the corrosion behaviour of X80 pipeline steel

The study encompasses the synthesis of an ionic liquid corrosion inhibitor using the ion exchange method. Its impact on the corrosion and hydrogen permeation behaviour of X80 pipeline steel in a CO2 environment is thoroughly investigated. The findings reveal that the corrosion resistance and hydrogen atom diffusion of X80 pipeline steel exhibit an initial decline, followed by an increase with escalating inhibitor concentration. The nadir values are recorded at an inhibitor concentration of 500 mg·L−1, attaining a remarkable maximum inhibition efficiency of 97%. Following the addition of corrosion inhibitors, the formation of corrosion products notably decreases, indicating a positive inhibition effect on both corrosion and hydrogen permeation. Additionally, a correlation is successfully established between hydrogen permeation parameters and inhibitor concentration.

Barnacle cement protein as an efficient bioinspired corrosion inhibitor

To prevent corrosion damage in aggressive environments such as seawater, metallic surfaces are coated with corrosion inhibitors usually made of organic molecules. Unfortunately, these inhibitors often exhibit environmental toxicity and are hazardous to natural habitats. Thus, developing greener and effective corrosion inhibitors is desirable. Here, we present an alternative green inhibitor, the recombinant protein rMrCP20 derived from the adhesive cement of the barnacle Megabalanus rosa and show that it efficiently protects mild steel against corrosion under high salt conditions mimicking the marine environment. We reveal that these anti-corrosion properties are linked to the protein’s biophysical properties, namely its strong adsorption to surfaces combined with its interaction with Fe ions released by steel substrates, which forms a stable layer that increases the coating’s impedance and delays corrosion. Our findings highlight the synergistic action of rMrCP20 in preventing corrosion and provide molecular-level guidelines to develop alternative green corrosion inhibitor additives.

Self-healing dicalcium phosphate dihydrate coating of biomedical magnesium and its in vitro biocompatibility evaluation

To improve the corrosion resistance and biocompatibility of magnesium (Mg) for biomedical applications, a novel coating comprising self-healing dicalcium phosphate dihydrate (DCPD) was applied to Mg using a simple deposition method, without the need for the addition of corrosion inhibitors. Scratch and immersion tests demonstrated that the prepared coating displayed impressive self-healing capabilities, with artificial scratches within 4 h when exposed to 0.9 wt% NaCl solution. The electrochemical test suggested that the DCPD-coating, whether scratched or not, provided effective corrosion protection for the Mg substrate. In vitro cell culture results revealed that the DCPD-coated samples exhibited superior biocompatibility compared to pure Mg. This work offers a new perspective on designing self-healing coatings for Mg, eliminating the need for additional corrosion inhibitors.

Effect of Molecular Structure of Thio-Chemicals on Corrosion Inhibition in CO2 Corrosive Environments

Summary Carbon dioxide (CO2) is frequently present in oil and gas fields, and its use in CO2 flooding for enhanced oil recovery is growing. However, CO2 is highly corrosive to steel in oilfield fluid. The effective and economical method for controlling corrosion is the addition of corrosion inhibitors for carbon steel materials. Thio-compounds of small size have shown potential as corrosion inhibitors to enhance the performance of imidazoline inhibitors. In this study, several small thio-derivatives inhibitors including mercaptoethanol (ME), thiourea (TU), mercaptoacetic acid (TGA), and 2-mercaptobenzimidazole (MBI) were compared to inhibit the CO2 corrosion. They were used as synergists to enhance corrosion inhibition of oleic imidazoline (OIM) on carbon steel in CO2-saturated brine at 60°C. The corrosion inhibition was evaluated using weight loss and electrochemical techniques, while the surface was characterized using atomic force microscopy (AFM). Additionally, quantum chemical calculations were conducted to investigate the mechanism of corrosion inhibition. The results demonstrate that the MBI, with its aromatic group, exhibited superior corrosion inhibition performance compared with ME, TGA, and TU. The surface characterization revealed no pitting and localized corrosion at 10 ppm of inhibitor. A proposed interaction model suggests that OIM becomes protonated and forms a coadsorption layer with MBI on the carbon steel surface through electrostatic attraction. MBI adsorbs onto iron through a bidentate binding-N-S-bridge connection, effectively preventing carbon steel corrosion in the CO2 environments. This research contributes to establishing a structure-properties relationship for thio-chemicals, aiding in the development of more efficient corrosion inhibitors.

Study of the effect of functionalization with inhibitors on the corrosion properties of PEO-coated additive manufactured AlSi10Mg alloy

Plasma electrolytic oxidation (PEO) was carried out on SLM-produced AlSi10Mg alloy using various corrosion inhibitor additives. The study investigated the effects of these additives on microstructural evolution, phase composition, and corrosion behavior by comparing the functionalized coating to a standard base silicate PEO one. The results revealed that, in most cases, the additives significantly altered the coatings' thickness, density, and adherence, leading to improved corrosion resistance due to an enhanced barrier effect over electrolyte penetration. Long-term immersion electrochemical impedance spectroscopy (EIS) tests proved the additives’ corrosion inhibitor capability, as they all were able to enhance coating stability.

Expired flunarizine hydrochloride as corrosion inhibitors for Q235 steel in hydrochloric acid medium: Experimental and computational investigation

The corrosion of carbon steel is always a very serious issue, and the addition of corrosion inhibitors is an effective approach to prohibiting the corrosion of carbon steel. Because expired drugs are environmentally friendly, green, and non‐toxic; thus, this work provides a new idea for the treatment of expired drugs. The expired flunarizine hydrochloride (FH) is used as corrosion inhibitors for Q235 steel, investigating the corrosion inhibition efficiency of expired FH with different concentrations for carbon steel and illustrating the corrosion inhibition mechanism. Electrochemical impedance and Tafel curves are used to investigate the corrosion inhibition of carbon steel under 1 M HCl solution with different concentrations of the expired FH, and the corrosion efficiency is calculated according to the immersion tests, and the corrosion inhibition efficiency is more than 88.5%. Scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FTIR), and Raman spectroscopy strongly support the results of the electrochemical experiment. Besides, the simulation results also provide the strong supports for the experimental results.

Experimental and theoretical investigations of 1,1′-Dibenzyl-[4,4′-bipyridine]−1,1′-diium chloride as effective corrosion inhibitor for Q235 steel in 1 M HCl

The addition of corrosion inhibitors has been extensively used as the simplest, most effective and inexpensive technique to inhibit corrosion in industry, and for this reason, this study investigated how 1,1′-Dibenzyl-[4,4′-bipyridine]− 1,1′-diium chloride (DBDC) affected Q235 carbon steel's ability to resist corrosion in 1 M HCl. The experimental study was conducted to determine how the compound suppresses corrosion of carbon steel by electrochemical techniques, and the findings demonstrated that DBDC is a powerful corrosion inhibitor that can stop Q235 carbon steel from corroding. Electrochemical impedance spectroscopy (EIS) results indicated that DBDC at a concentration of 400 ppm had a corrosion inhibition efficiency of 95.83% at 298 K ambient temperature. The polarization curves suggested that DBDC could act as a mixed inhibitor and reduce the corrosion current density. The adsorption of compound on Q235 steel surface conformed to Langmuir isothermal adsorption line, and the related thermodynamic parameters were discussed, as well as the influence of the analyzed temperature on efficiency of corrosion inhibition. The surface morphology of Q235 carbon steel was examined under different corrosion inhibitor conditions, the results confirmed that the inhibitor can adsorb on the surface of carbon steel to form a protective film. The role of DBDC molecular structure in the corrosion inhibition process was surveyed by theoretical calculation methods, the results showed that the DBDC molecule could be adsorbed on metal surface by pyridine ring and benzene ring.

Preparation of Bis-Thiophene Schiff Alkali-Copper Metal Complex for Metal Corrosion Inhibition.

Due to the obvious numerous economic and technical consequences of the corrosion process, its inhibition is one of the most critical aspects of current research. A corrosion inhibitor for the bis-thiophene Schiff base copper-metal complex Cu(II)@Thy-2 was investigated here, which was synthesized via a coordination reaction with a bis-thiophene Schiff base (Thy-2) as a ligand and copper chloride (CuCl2-2H2O) as a ligand metal salt. When the corrosion inhibitor concentration was increased to 100 ppm, the self-corrosion current density Icoor reached a minimum of 2.207 × 10-5 A/cm2, the charge transfer resistance reached a maximum of 932.5 Ω·cm2, and the corrosion inhibition efficiency reached a maximum of 95.2%, with the corrosion inhibition efficiency showing a trend of increasing first and then decreasing with concentration increase. After adding Cu(II)@Thy-2 corrosion inhibitor, a uniformly distributed dense corrosion inhibitor adsorption film formed on the surface of the Q235 metal substrate, significantly improving the corrosion profile compared to both before and after the addition of the corrosion inhibitor. Before and after the addition of corrosion inhibitor, the metal surface's contact angle CA increased from 54.54° to 68.37°, showing that the adsorbed corrosion inhibitor film decreased the metal surface's hydrophilicity and increased its hydrophobicity.

Application of Biomass Corrosion Inhibitors in Metal Corrosion Control: A Review

Corrosion is the process of damaging materials, and corrosion of metallic materials frequently results in serious consequences. The addition of corrosion inhibitors is the most effective means of preventing metal corrosion. Until now, researchers have made unremitting efforts in the research of high-efficiency green corrosion inhibitors, and research on biomass corrosion inhibitors in a class of environmentally friendly corrosion inhibitors is currently quite promising. This work presents the classification of green biomass corrosion inhibitors in detail, including plant-based corrosion inhibitors, amino acid corrosion inhibitors, and biosurfactant corrosion inhibitors, based on the advantages of easy preparation, environmental friendliness, high corrosion inhibition efficiency, and a wide application range of biomass corrosion inhibitors. This work also introduces the preparation methods of biomass corrosion inhibitors, including hydrolysis, enzymatic digestion, the heating reflux method, and microwave extraction. In addition, the corrosion inhibition mechanisms of green biomass corrosion inhibitors, including physical adsorption, chemisorption, and film-forming adsorption, and evaluation methods of biomass corrosion inhibitors are also explicitly described. This study provides valuable insights into the development of green corrosion inhibitors.

Revealing the Correlation between Molecular Structure and Corrosion Inhibition Characteristics of N-Heterocycles in Terms of Substituent Groups

Controlling metal corrosion can directly address the waste of metal and the environmental pollution and resource depletion caused by metal recycling, very significant factors for green and sustainable development. The addition of corrosion inhibitors is a relatively cost-effective means of corrosion prevention. Among these, N-heterocycles have been widely used because heteroatoms contain lone pairs of electrons that can be strongly adsorbed onto metals, protecting them in highly corrosive environments at relatively low concentrations. However, due to the large variety of N-heterocycles, their corrosion inhibition characteristics have seldom been compared; therefore, the selection of appropriate N-heterocycles in the development of anti-corrosion products for specific applications was very difficult. This review systematically analyzed the influence of different substituents on the corrosion inhibition performance of N-heterocycles, including different alkyl chain substituents, electron-donating and electron-withdrawing substituents, and halogen atoms, respectively. The correlation between the molecular structure and corrosion inhibition characteristics of N-heterocycles was comprehensively revealed, and their action mechanism was analyzed deeply. In addition, the toxicity and biodegradability of N-heterocycles was briefly discussed. This study has provided a significant guideline for the development of green, promising corrosion inhibitors for advanced manufacturing and clean energy equipment protection.

Formation of protective conversion coating on Mg surface by inorganic inhibitor

In the present work, NaH2PO4 was proved to be a highly efficient inhibitor to enhance barrier properties of the corrosion product layer on AM50 Mg alloy. Formation of typical porous and non-protective Mg(OH)2 based corrosion product layer is suppressed after addition of corrosion inhibitor in 3.5 wt% NaCl solution, while a dense and protective chemical conversion coating appears on the active Mg surface. The phase composition of the conversion-like coating is mainly composed of MgHPO4 and Mg3(PO4)2, leading to significantly enhanced corrosion and tribocorrosion performance compared to corrosion produced layer formed in 3.5 wt% NaCl solution.

Exploration of novel polyaspartic acid derivatives as fluorescent eco-friendly corrosion inhibitors for the carbon steel: Electrochemical, surface analysis (SEM/XPS) and theoretical calculation

The addition of corrosion inhibitors can effectively improve the hazards posed by the corrosion of carbon steel in circulating cooling water. From the economic and environmental perspective, it makes sense to develop eco-friendly corrosion inhibitors that can be monitored online. In the present work, three polyaspartic acid (PASP) derivatives modified with benzothiazole compounds (R-ABT: R=H, Me and OMe) were synthesized as fluorescent green corrosion inhibitors for the first time, which have good thermostability and allow online detection by fluorescence spectroscopy. The corrosion performance of three inhibitors on carbon steel in cooling water was investigated using the electrochemical test, weight loss measurement, scanning electron microscopy, atomic force microscopy, contact angle test, X-ray photoelectron spectroscopy, density functional theory (DFT) and molecular dynamic (MD) simulation. The electrochemical tests indicate that all three derivatives are mixed-type inhibitors and their corrosion inhibition capacity is ranked as follows: PASP-OMe-ABT (96.45%) > PASP-Me-ABT (91.38%) > PASP-H-ABT (89.38%). The three inhibitor molecules improve the carbon steel surface by physisorption and chemisorption as shown by weight loss tests and surface analysis. XPS analysis further confirms the presence of a compound film on the metal surface. Meanwhile, the difference in the radial distribution function and diffusion coefficient of the three derivatives on the Fe (110) surface was also in-depth revealed by quantum chemical calculation based on DFT and MD simulation. The theoretical data obtained strongly support the experimental results and confirm that the introduction of methoxy enhances the corrosion inhibition performance.

L-Ascorbic Acid as an Efficient Green Corrosion Inhibitor of Steel Rebars in Chloride Contaminated Cement Mortar.

Corrosion of reinforcement is a major problem regarding concrete durability. In new structures the corrosion onset can be delayed if additional protection methods are provided as is the case for the addition of corrosion inhibitors in the concrete mix. The main goal of this paper is the evaluation of the effect of the ascorbic acid (AA) as a green steel corrosion inhibitor in cement mortars contaminated by chlorides. Concentration levels of ascorbic acid, ranging from 0.5 to 10-3 mol/L, were added to the mixing water. Electrochemical methods, including corrosion potential (Ecorr), linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS), were employed to assess the corrosion rate of the steel embedded in the mortars. The corrosion inhibiting performance of ascorbic acid was compared with that of sodium nitrite. The interaction of the ascorbic acid with the hydrated cement matrix was also evaluated with differential thermal and thermogravimetric analysis (DTA/TG) and pH measurements. The results indicated that, depending on the ascorbic acid concentration, it can be an activator of the corrosion process or an effective corrosion inhibitor in a similar manner to sodium nitrite. A corrosion rate decrease was achieved with concentrations below 10-2 mol/L and the optimum content was 10-3 mol/L. Within this concentration range, the AA does not modify the hydration performance of the cement matrix.

The effect of additions of anticorrosive pigments on the cathodic delamination and wear resistance of an epoxy powder coating

The cathodic delamination and wear resistance of epoxy powder coatings were evaluated after adding 3 % (by wt.) of calcium ion exchanged micropigments from amorphous synthetic silica. The materials were manufactured through the innovative and economical hot mixing method, and three different coatings were considered: commercial epoxy, epoxy without micropigments submitted to the hot mixing treatment, and epoxy with micropigments. The curing kinetics of the powder coatings was studied in order to evaluate the possible effects of the micropigments on the epoxy, using differential scanning calorimetry (DSC). In addition, mechanical properties of coatings (hardness and scratch resistance) and their wear resistance (reciprocal tribometer tests) were assessed. After provoking a controlled mechanical failure in the coatings, their delamination resistance was analyzed by scanning Kelvin probe (SKP). The delamination front was calculated after adding a drop of 3.5 % NaCl solution and taking measurements for 26 days. The results show that the corrosion attack progresses through a cathodic delamination mechanism. The addition of corrosion inhibitors in epoxy powder coatings has not only allowed a considerable improvement in delamination resistance, but has also led to greater mechanical and wear resistance. At the same time, it has simultaneously reduced the chances for mechanical failure of the coating and decreased the progression rate of damage, if it occurs. The study has also been completed with electrochemical impedance spectroscopy and polarization measured of fully-immersed defective coatings in 3.5 % NaCl.