Synthesis, Characterization, and Computational Chemical Study of Aliphatic Tricationic Surfactants as Corrosion Inhibitors for Metallic Equipment in Oil Fields

Evaluation of ionic liquids based imidazolium salts as an environmentally friendly corrosion inhibitors for carbon steel in HCl solutions

The features of this work on corrosion inhibition have been investigated based on the ecological awareness and according to the strict environmental legislations. This was done by studying how different imidazolium derivatives ionic liquids containing different alkyl chains R8, R10 and R12 affected the corrosion reaction of carbon steel specimen immersed in 1 M hydrochloric acid at various temperatures. Weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy were utilized to examine the corrosion inhibition behavior on carbon steel. In addition, FT-IR spectroscopy was used to analyze the coated film that has been formed on the metal surface. The prepared ionic liquids showed effective inhibition efficiency, where the corrosion rate after the using of 100 ppm of R8-IL, R10-IL and R12-IL was decreased from 5.95 (µg cm-2 min-1) to 0.66, 0.56, and 0.44 (µg cm-2 min-1), respectively at 20 °C. In the polarization curves, the corrosion current, Icorr, decreases by ILs addition and suggest that ILs act as mixed type inhibitors. From EIS findings, the increase in Rct and decrease in Cdl values proves the adherence of inhibitor molecules on carbon steel surface. The temperature effect was also studied on the film formed, where increasing the temperature from 20 to 50 °C, the corrosion rate increased and the inhibitors efficacy decreased. The increasing in the length of the attached alkyl chain, the efficacies of the prepared inhibitors increases. Various thermodynamic parameters such as the reaction activation free energy (ΔG*), the entropy of activation (ΔS*), and the enthalpy of activation (ΔH*), as well as the adsorption isotherm were investigated in order to interpret the mechanism and obtain the most accurate perception.

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.

Construction, Characterization, DFT Computational Study, and Evaluation the Performance of Some New N-Amino Pyridinone Schiff Base Catalyzed with Ceric(IV) Ammonium Nitrate (CAN) as Corrosion Inhibitors in Some Petroleum Applications

In this paper, two novel organic inhibitors, TAP-TPP and TAP-CEQ, were prepared via Schiff base condensation as a green chemistry methodology using an eco-friendly catalyst, ceric ammonium nitrate, with a high yield (87% and 91%), and characterized via elemental analysis, FTIR, 1H, and 13C NMR spectroscopic analysis tools. Weight loss assessment was utilized as a chemical testing method, and the maximum inhibition efficiency of TAP-TPP and TAP-CEQ is 89.4% and 91.8%, respectively. PDP and EIS were electrochemical measures to determine the efficacy of both inhibitors as anticorrosion for carbon steel alloys in 2 M HCl aggressive media. The collected electrochemical results demonstrated that both inhibitors behaved as excellent anticorrosion agents for metallic constructions. According to the potentiodynamic polarization (PDP) analysis, these organic inhibitors worked as mixed-type inhibitors. The adsorption isotherm revealed that undertaken compounds obeyed Langmuir adsorption isotherm with the free energies of adsorption of ranged from ΔG = − 34.29 to − 34.63 kJ Mol−1. Also, electrochemical impedance spectroscopy (EIS) data confirmed that the values charge transfer resistance (Rct) was increased by increasing the concentration of the injected inhibitor molecules. In contrast, the electrochemical double layer (Cdl) was dramatically decreased. The work was supported by two-surface analysis methods such as SEM and EDX. For more details, the values of percentage inhibition efficiency can be ordered as follows: TAP-CEQ > TAP-TPP. Finally, a suitable inhibition mechanism and theoretical studies including EHOMO, ELUMO, diploe moment (µ), and electrophilicity index (ω) were assumed and discussed in detailed.

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

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

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.

Synthesis and inhibitive characteristic of two acryloyl chloride derivatives towards the corrosion of API 5L X52 carbon steel in hydrochloric acid medium

Two new organic based corrosion compounds were prepared from Acryloyl chloride are namely: N,N-bis(2-hydroxyethyl) acrylamide (DEA) and N-(2-hydroxyethyl) acrylamide (MEA). The prepared compounds were studied as corrosion inhibitors for carbon steel (CS) in 1 M hydrochloric acid solution while the efficiency of the prepared compounds were studied through different chemical (weight loss, WL) and electrochemical techniques [potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS)] in addition to, the theoretical techniques as Quantum chemical calculations, Monte Carlo simulation and the surface morphology study using atomic force microscopy (AFM). The obtained results showed that the investigated compounds are working as good corrosion inhibitors, the inhibition efficacy (%IE) increases with the increase of the compound concentrations. However, the %IE decreases with the rise in the temperature proving that the adsorption of the inhibitor molecules on the CS surface is physisorption, while the polarization data revealed that these compounds are classified as mixed kind inhibitors, that inhibits both anodic and cathodic reactions. Results reveal that DEA and MEA exhibit an excellent %IE of 89.2 and 71.6% at 60 ppm for DEA and MEA, respectively. The adsorption of the inhibitor molecules on CS surface following Langmuir adsorption isotherm. There is a strong matching between results obtained from experimental and theoretical studies. The order of the investigated inhibitors based on the %IE is DEA > MEA.

Novel cationic aryl bithiophene/terthiophene derivatives as corrosion inhibitors by chemical, electrochemical and surface investigations

Two novel bithienyl fluorobenzamidine derivatives namely, 4-([2,2':5',2''-terthiophen]-5-yl)-2-fluorobenzamidine hydrochloride salt (MA-1615), 5'-(4-amidino-3-fluorophenyl)-[2,2'-bithiophene]-5-carboxamidine dihydrochloride salt (MA-1740) were synthesized, characterized and their corrosion inhibition properties were evaluated by electrochemical methods for carbon steel (C-steel) in 1 M HCl. Experimental investigations revealed that the inhibition effectiveness of the investigated inhibitors (INHs) by the Tafel polarization method followed the order: MA-1740 (96.9%) > MA-1615 (95.6%), demonstrating higher efficiency than inhibitors of similar structure reported in the literature. The investigated bithiophene derivatives exhibit mixed-type corrosion inhibition characteristics by blocking the active sites on the surface of C-steel. EIS study revealed that the INHs behave as interface-type corrosion inhibitors. UV-Visible spectrometric measurements confirmed a complex formation between the Fe2+ cation released during the corrosion reactions and inhibitor molecules.

Corrosion Control of Carbon Steel in Water-Based Mud by Nanosized Metallo-Cationic Surfactant Complexes During Drilling Operations

In this work, three nanometal complexes named cetyltrimethyammonium dibromodichloro zincate (CT-Zn), cetyltrimethyammonium dibromodichloro cuprate (CT-Cu), and cetyltrimethyammonium dibromodichloro manganesate (CT-Mn) were prepared, characterized, and evaluated as corrosion inhibitors for carbon steel in water-based mud (WBM). The chemical structure of the prepared complexes was confirmed by the use of Fourier transform infrared spectroscopy, Raman spectroscopy, elemental analysis, atomic absorption spectroscopy, dynamic light scattering, and thermogravimetric analysis techniques. The surface tension of the complexes was measured. The critical micelle concentrations and some of the surface properties were also determined. The compounds were evaluated as corrosion inhibitors for carbon steel in the prepared WBM using potentiodynamic polarization and weight loss methods during the static and dynamic conditions of the drilling operations. The results indicated that the prepared metal complexes showed high anticorrosion action as the inhibition efficiency increased gradually with the increase in the concentrations of the prepared complexes until it reached the maximum value (93.1%) at 300 ppm for CT-Cu. The order of inhibition efficiency of these inhibitors was as follows: CT-Cu > CT-Zn > CT-Mn. The polarization curves showed that these complexes acted as mixed-type inhibitors. According to the results, the adsorption of these compounds obeyed Langmuir adsorption isotherm. Surface analysis of the carbon steel samples was investigated using scanning electron microscopy, energy dispersive X-ray, and X-ray diffraction techniques. Rheological properties, gel strength, thixotropy, and filtration properties were also measured according to American Petroleum Institute specifications.