Anti-corrosion, antiscalant and anti-microbial performance of some synthesized trimeric cationic imidazolium salts in oilfield applications

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).

Effective Treatment Methodology for Environmental Safeguard Catalytic Degradation of Fluconazole by Permanganate Ions in Different Acidic Environments: Kinetics, Mechanistics, RSM, and DFT Modeling

In this paper, the degradation of fluconazole drug (Flz) was explored kinetically utilizing permanganate ion [MnO4-] as an oxidant in different acidic environments, namely sulfuric and perchloric acids at various temperatures. Stoichiometry of the reactions between Flz and [MnO4-] in both acidic environments was attained to be 1.2 ± 0.07 mol. The kinetics of the degradation reactions in both cases were the same, being unit order regarding [MnO4-], fewer than unit orders in [Flz], and fractional second orders in acid concentrations. The rate of oxidative degradation of fluconazole in H2SO4 was higher than that in HClO4 at the same investigational circumstances. The addition of small amounts of Mg2+ and Zn2+ enhanced the degradation rates. The activation quantities were evaluated and debated. The gained oxidation products were characterized using spot tests. A mechanistic approach for the fluconazole degradation was suggested. Finally, the rate law expressions were derived which were agreed with the acquired outcomes. The rates of degradation for various [Flz] were mathematically modeled using the response surface methodology (RSM). The RSM model's conclusions and the experimental findings are in agreement. The oxidative degradation mechanism of Flz using density functional theory (DFT) was performed. The fluconazole drug degrades in acidic settings, protecting both the environment and human health, according to a method that is easy to use, powerful, inexpensive, practical, affordable, and safe.

Effect of Adsorption and Interactions of New Triazole-Thione-Schiff Bases on the Corrosion Rate of Carbon Steel in 1 M HCl Solution: Theoretical and Experimental Evaluation

Due to the unique properties of steel, including its hardness, durability, and superconductivity, which make it an essential material in many industries, it lacks corrosion resistance. Herewith, two novel triazole-thione Schiff bases, namely, (E)-5-methyl-4-((thiophen-2-ylmethylene)amino)-2,4-dihydro-3H-1,2,4-triazole-3-thione (TMAT) and (E)-4-(((5-(dimethylamino)thiophen-2-yl)methylene)amino)-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (DMTMAT), were synthesized and characterized. The corrosion inhibition (CI) ability of these two molecules on carbon steel in an aqueous solution of 1 M HCl as well as their interaction with its surface was studied using a number of different techniques. The results confirmed that the CI capability of these organic molecules depends on their strong adsorption on the metal surface and the formation of a protective anticorrosion film. Weight loss tests revealed that the inhibition efficiencies of TMAT and DMTMAT were 91.1 and 94.0%, respectively, at 1 × 10-3 M concentrations. The results of electrochemical impedance spectroscopy (EIS) indicated that there was a direct relationship between the inhibitor concentration and the transfer resistance. Potentiodynamic polarization (PDP) experiments have proven to be mixed-type inhibitors of C-steel in aqueous hydrochloric acid solution and follow the Langmuir adsorption isotherm model. Several thermodynamic and kinetic parameters were calculated. The negative values of the adsorption-free energy are -36.7 and -38.5 kJ/mol for TMAT and DMTMAT, respectively, confirming the spontaneity of the adsorption process. The MD simulation study's findings show that the inhibitor molecules are nearly parallel to the metal surface. The interaction energy calculated by the MD simulation and the inhibitory trend are the same. The practical implementation is consistent with what the computer models predicted.

Novel biphenylidene-thiopyrimidine derivatives as corrosion inhibitors for carbon-steel in oilfield produced water

The inhibiting efficiency of three newly synthesized organic compounds:5-((4'-(dimethylamino)-[1,1'-biphenyl]-4-yl)methylene)-1,3-diethyl-2-thioxodihydropyrimidine-4,6(1H,5H)-dione (HM-1228), 5-((4'-(dimethylamino)-[1,1'-biphenyl]-4-yl)methylene)-2-thioxodihydropyrimidine-4,6(1H,5H)-dione (HM-1227) and 5-((4'-(dimethylamino)-[1,1'-biphenyl]-4-yl)methylene)pyrimidine-2,4,6(1H,3H,5H)-trione (HM-1226) in oilfield produced water on the corrosion of carbon steel has been examined via electrochemical measurements; potentiodynamic polarization (PDP) and electrochemical impedance (EIS) techniques. The adsorption of these compounds on the surface of carbon steel followed Langmuir isotherm. In addition, the surface morphology of uninhibited and inhibited carbon steel was examined by Atomic Force Microscopy (AFM), observing surface improvement when carbon steel samples exposed to the inhibited corrosive solutions. The average surface roughness (Ra) in oilfield produced water solution in the presence of 0.5 mM of HM-1228 inhibitor was 138.28 nm compared to the uninhibited surface 571.62 nm. To explore the corrosion inhibition mechanism, quantum chemical calculations and Monte Carlo simulations were utilized. The HM-1228 inhibitor demonstrated the highest corrosion inhibition efficiency at 94.8% by PDP measurements. The higher corrosion inhibition of compound HM-1228 can be attributed to the presence of di-N-ethyl groups that enhance both electron donating ability and lipophilic properties.

Optimization, Kinetics, and Isotherm Studies of Methyl Thioninium Chloride Removal from Simulated Solutions Using Chitosan Derivatives

Methylene blue (MB) dye or methyl thioninium chloride is one of the hazardous cationic dyes that are discharged into the textile effluent causing a highly negative environmental impact. The present work targets the investigation of the adsorption performance of some chitosan-modified products toward the MB dye from simulated solutions. The claimed chitosan derivatives were prepared, characterized, and applied for the removal of lead and copper cations from an aqueous medium in a previous work. These include: N,O-carboxymethyl chitosan (N,O-CM/Cs), chitosan grafted with glutaraldehyde (Cs/GA), chitosan cross-linked with GA/epichlorohydrin (Cs/GA/ECH), and chitosan cross-linked with glutaraldehyde/methylene bis(acrylamide) (Cs/GA/MBA). The modified chitosan derivatives in this study displayed outstanding mechanical qualities, exceptional reusability, and a significant amount of adsorption capacity. The ability of prepared Cs derivatives to eradicate MB was as follows: N,O-CM/Cs (95.1 mg/g) < Cs/GA (120.1 mg/g) < Cs/GA/ECH (220.1 mg/g) < Cs/GA/MBA (270.0 mg/g). The swelling performance of the prepared sorbents was verified under different experimental conditions, and the data revealed that the maximum swelling was attained at pH = 9, temperature 55 °C, and after 24 h. The produced Cs derivatives showed exceptional reusability by maintaining higher adsorption effectiveness throughout five cycles. The MB dye was adsorbed onto the modified derivatives according to pseudo-second-order kinetics and the Langmuir model. Moreover, the adsorption process was monitored via atomic force microscopy to verify the differences between the dye-free and dye-loaded adsorbents.

Fluorescence Naphthalene Cationic Schiff Base Reusable Paper as a Sensitive and Selective for Heavy Metals Cations Sensor: RSM, Optimization, and DFT Modelling

Heavy metals are particularly damaging contaminants in the environment, and even trace concentrations represent a risk to human health due to their toxicity. To detect the heavy metals of Mn2+ and Co2+ ions, a novel selective reusable paper-based Fluorescence naked-eye sensor based on naphthalene cationic Schiff base (NCSB) was synthesized and confirmed using FT-IR, 1 H-NMR, and MS tools. Based on a blue to colorless color change in the aqueous solution, the NCSB sensor is utilized to Mn2+ and Co2+ cations selectively among other metal ions (Fe2+, Cu2+, Mg2+, Ni2+, Zn2+, Cd2+, Hg2+, Pb2+, Sn2+ and Cr3+). In the aqueous medium, the NCSB sensor displayed high sensitivity, with limits of detection (LOD) values of 0.014 µM (14.08 nM) and 0.041 µM (41.47 nM) for Mn2+ and Co2+ cations, respectively. The paper-based sensor naked-eye detected Mn2+ and Co2+ cations in water at concentrations as low as 0.65 µM (65 nM) and 0.086 µM (86 nM), respectively. It was discovered that 5 min of incubation time and a pH range of 7 to 11 were optimal for the complexation reaction between the Mn2+ and Co2+ ions and the NCSB sensor. Through a static quenching process, the interaction of the different metal ions with the Schiff base group in the NCSB molecule results in the development of a ground-state non-fluorescent complex. NCSB sensor was also successfully applied in analysis of Mn2+ and Co2+ in environmental water with good recoveries of 94.8-105.9%. The theoretical calculations based on density functional theory (DFT) studies are in support of experimental interpretations. The links between the input factors and the anticipated response were evaluated using the quadratic model of the response surface methodology (RSM) modeling.

1-Butyl-3-methylimidazolium methane sulfonate ionic liquid corrosion inhibitor for mild steel alloy: Experimental, optimization and theoretical studies

The current research reports the performance of 1-butyl-3-methylimidazolium methane sulfonate ([C4MIM][OMs](IL)) as effective corrosion inhibitor for mild steel in 1 M H2SO4 electrolyte. For proper evaluation, weight loss, electrochemical study, theoretical modeling and optimization techniques were used. Weight loss and electrochemical methods shows that the inhibition performance of [C4MIM][OMs] on the metal surface strengthens as the concentration increases. Maximum inhibition efficiency of 85.71%, 92.5% and 91.1% at 0.8 g L-1 concentration of [C4MIM][OMs] were obtained from the weight loss, polarization and impedance studies, respectively. In addition, response surface methodology (RSM) a statistical tool was used for modeling and optimization of the empirical data. The RSM model validates the empirical findings. Also, DFT/MD-simulation investigations evidenced that [C4MIM][OMs] forms a barrier film on the mild steel surface. The result shows that the synthesized [C4MIM][OMs] could open up opportunities in corrosion and materials protection for sustainability.

Developing novel imidazoline-modified glucose derivatives as eco-friendly corrosion inhibitors for Q235 steel

Many natural compounds and imidazoline derivatives have been previously evaluated as eco-friendly corrosion inhibitors for application in the food, pharmaceutical and chemical industries. Herein, a novel alkyl glycoside cationic imaginary ammonium salt (FATG) was designed via the grafting of imidazoline molecules into the skeleton of a glucose derivative, and its effects on the electrochemical corrosion behavior of Q235 steel in 1 M HCl were systemically investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curves (PDP), and gravimetric measurements. The results indicated that its maximum inhibition efficiency (IE) was 96.81% at a concentration as low as 500 ppm. The adsorption of FATG on the Q235 steel surface followed the Langmuir adsorption isotherm. The scanning electron microscopy (SEM) and diffraction X-ray (XRD) results suggested the formation of inhibitor film on the metal surface, which significantly impeded the corrosion of Q235 steel. Additionally, FATG showed a high biodegradability efficiency (98.4%), which had great potential as a green corrosion inhibitor based on concepts of greenness and biocompatibility.

DFT Study on Corrosion Inhibition by Tetrazole Derivatives: Investigation of the Substitution Effect

Corrosion is one of the problems that most industries face. Our aim in the current study is to perform density functional theory calculations and Monte Carlo simulation to theoretically investigate the corrosion inhibition of the copper (1 1 1) surface by tetrazole molecules and a group of their derivatives. These compounds have electron-donating groups (CH₃, CH₃O, and OH) and electron-withdrawing groups (F, CN, and NO₂). Two different isomeric forms of tetrazole molecules and their derivatives, including 1H and 2H tautomers, were studied in two configurations, parallel and perpendicular to the Cu (1 1 1) surface. With the help of DMol3 calculations, the most important parameters related to the molecular ability of tetrazole derivatives as corrosion inhibitors include the adsorption energy (ΔE), E _HOMO, E _LUMO, E _gap, and issues related to chemical reactions, including total hardness (η), electronegativity (χ), and electron fraction transitions from the anti-corrosion molecule to the copper atom (ΔN), were calculated and compared in the tetrazole molecules and their derivatives. Also, with the help of adsorption locator calculations, the inhibitory effects of these compounds were theoretically investigated in an acidic environment. Through these calculations, it was determined that tetrazole molecules with electron-donating groups adsorbed perpendicularly to the copper (1 1 1) surface, by forming a stronger bond, are considered suitable corrosion inhibitors. Also, among the examined molecules, the 2H-tetrazole isomer form plays a more influential role than the 1H-tetrazole form.

Experimental and Computational Exploration of Chitin, Pectin, and Amylopectin Polymers as Efficient Eco-Friendly Corrosion Inhibitors for Mild Steel in an Acidic Environment: Kinetic, Thermodynamic, and Mechanistic Aspects

Herein, the inhibition impacts of chitin, pectin, and amylopectin as carbohydrate polymers on the corrosion of mild steel in 0.5 M HCl were researched utilizing various experimental and theoretical tools. The acquired outcomes showed that the inhibition efficiencies (% IEs) of the tested carbohydrate polymers were increased by raising their concentrations and these biopolymers acting as mixed-kind inhibitors with major anodic ones. The acquired % IEs values were reduced with rising temperature. The higher % IEs of the tested polymers were inferred via powerful adsorption of the polymeric molecules on the steel surface and such adsorption obeyed the Langmuir isotherm. The computed thermodynamic and kinetic quantities confirmed the mechanism of physical adsorption. The kinetics and mechanisms of corrosion and its protection by polymeric compounds were illuminated. The results obtained from all the techniques used confirmed that there was good agreement with each other, and that the % of IEs followed the sequence: chitin > amylopectin > pectin.

Computational Foretelling and Experimental Implementation of the Performance of Polyacrylic Acid and Polyacrylamide Polymers as Eco-Friendly Corrosion Inhibitors for Copper in Nitric Acid

Copper is primarily used in many industrial processes, but like many other metals, it suffers from corrosion damage. Polymers are not only one of the effective corrosion inhibitors but also are environmentally friendly agents in doing so. Hence, in this paper, the efficacy of two polyelectrolyte polymers, namely poly(acrylic acid) (PAA) and polyacrylamide (PAM), as corrosion inhibitors for copper in molar nitric acid medium was explored. Chemical, electrochemical, and microscopic tools were employed in this investigation. The weight-loss study revealed that the computed inhibition efficiencies (% IEs) of both PAA and PAM increased with their concentrations but diminished with increasing HNO₃ concentration and temperature. The results revealed that, at similar concentrations, the values of % IEs of PAM are slightly higher than those recorded for PAA, where these values at 298 K reached 88% and 84% in the presence of a 250 mg/L of PAM and PAA, respectively. The prominent IE% values for the tested polymers are due to their strong adsorption on the Cu surface and follow the Langmuir adsorption isoform. Thermodynamic and kinetic parameters were also calculated and discussed. The kinetics of corrosion inhibition by PAA and PAM showed a negative first-order process. The results showed also that the used polymers played as mixed-kind inhibitors with anodic priority. The mechanisms of copper corrosion in nitric acid medium and its inhibition by the tested polymers were discussed. DFT calculations and molecular dynamic (MD) modelling were used to investigate the effect of PAA and PAM molecular configuration on their anti-corrosion behavior. The results indicated that the experimental and computational study are highly consistent.

Corrosion in seawater desalination industry: A critical analysis of impacts and mitigation strategies

In the current world, freshwater production by clean energy sources with minimum environmental footprints is the main challenge for humankind which is dramatically deteriorating by overexploitation of available water resources. Seawater desalination technology greatly contributes to the mitigation of these serious conditions to produce potable water. However, because desalination plants handle extremely aggressive seawater under stringent operational conditions, they are highly vulnerable to insidious effects of corrosion primarily in the form of general and localized corrosion. Moreover, mineral scaling and bio-fouling are major challenges that further exacerbate corrosion phenomena. So, to ensure the continual operation and curbing corrosion in seawater desalination systems, strict monitoring and selection of highly corrosion-resistance materials are of prime concern. The present paper briefly explores fundamental concepts of corrosion in the desalination industry besides discussing different mitigation strategies for reducing the pernicious effects of corrosion which gravely impair environment quality and durability of desalination infrastructures. Moreover, the authors propose the knowledge gaps and perspectives to delineate the future research direction. Effective solutions for avoiding seawater stagnation, developing highly sophisticated coatings and surface modification technologies, application of advanced computational programs for accurate prediction of possible corrosion failure in desalination plants, and using quantum technology and magnetic corrosion inhibitor in seawater desalination are recommended as an urgent future research focus to combat against corrosion. On the whole, despite outstanding breakthroughs in the field of corrosion control in the desalination industry, the long-term performance of current materials is highly controversial as still many cases of corrosion failures have been reported which indicates the necessity of intensive research work.

The Role of Some Cationic Surfactants Based on Thiazine as Corrosion Inhibitors in Petroleum Applications: Experimental and Theoretical Approach

Two cationic surfactants based on thiazine, dodecyl thiazin bromide (DTB) and hexyl thiazin bromide (HTB), were synthesized, characterized, and investigated as corrosion inhibitors for API X-65 type steel in oil wells' formation water under an H₂S environment. Various spectroscopic techniques such as FTIR and ¹H NMR were used to confirm the DTB and HTB chemical structures. The corrosion inhibition efficiency of the selected compounds was investigated using both potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. The innovation of the current study is the existence of a long chain in the inhibitor molecule, which leads to an increase in the performance of the surfactant as a corrosion inhibitor, due to the increase in the surface area per molecule. It was found that these surfactants act as mixed-type inhibitors, leading to suppression of both the cathodic and the anodic processes by its adsorption on the electrode surface according to the Langmuir adsorption isotherm. Carbon steel's inhibitory mechanism was studied using an analogous circuit. The scanning electron microscope technique was used as a suitable analysis tool to show the nature of the layer designed on carbon steel. Quantum chemical calculations and Monte Carlo simulation techniques were used to support the obtained experimental results. Finally, a suitable mechanism for the inhibition process was proposed and discussed.

Effect of wet Hydrogen Sulfide on Carbon Steels Degradation in Refinery Based on Case Study

Material degradation caused by wet hydrogen sulfide (Wet H2S) is one of the major issues in refineries. Carbon steel is the main construction material used in refineries and is subjected not only to thickness loss but the hydrogen is the major concern. H2S leads to high atomic hydrogen penetration in steel which causes degradation in the form of blistering and/or cracking (HIC/SOHIC) and stress cracking in the area of welds and heat affected zones. Mechanism is unusually dangerous due to high difficulty of threat assessment, which is mostly based on ultrasonic measurements or calculations based on the API standards. This research is based on evaluation of the real threat of wet H2S degradation based on examination of construction materials after 41 years of exploitation in refinery. The comparison of the theoretical calculation based on API standards and experience of the degradation of the real objects was characterized. Laboratory measurements include mechanical tests involving the elongation in the function of tensile stress and deformation, with analysis of material hardness and gas chromatography analysis. The results are complemented by studies of the chemical composition of the streams and analytical studies of the hydrogen content in the material obtained by the gas chromatography method. The tests showed compliance of the standard analysis of the corrosion risk with the laboratory tests performed on the real samples. Research leads to indication of the destructive methods which can be used on the materials obtained during scheduled material replacements or installation modernizations.

Environmental Remediation through Catalytic Inhibition of Steel Corrosion by Schiff’s Bases: Electrochemical and Biological Aspects

The environmental impact of corrosion is very dangerous and consumes much of world’s efforts and funds. This work discusses the safeguarding of the environment, metals, and metal-infra structures by efficient Schiff’s base inhibitors. The corrosion inhibitors [(1E,3E)-N1,N3-dibutyl-1-(thiophen-2-yl)butane-1,3-diimine] (GSB-I) and [(1Z,3Z)-N1,N3-bis(4-methylhexan-2-yl)-1-(thiophen-2-yl)butane-1,3-diimine] (GSB-II) were successfully synthesized and evaluated for the protection of API 5L X65 steel (CS) in 1 M HCl media using electrochemical techniques, SEM/EDS, and quantum chemical calculations. GSB-I and GSB-inhibitory I’s efficiency is proportional to the concentration of the test. In the presence of 1 mM GSB-I and GSB-II, the maximum inhibitory efficiency was determined to be 90.6 and 93.8 percent, respectively. According to potentiodynamic polarization tests, the two compounds are effective inhibitors of mixed-type corrosion. The physisorption and chemisorption of both inhibitors followed the Langmuir adsorption isotherm on CS surfaces. The biological reactivity of both GSB has been examined, and encouraging results have been obtained as antifungal, antibacterial, and biocidal agents against sulfate-reducing bacteria (SRB). In addition, using DFT calculations and molecular dynamic (MD) simulation, the effect of GSB-I and GSB-II molecular configuration on corrosion inhibition behavior in acidic environments was investigated.