Nontoxic corrosion inhibitors for N80 steel in hydrochloric acid

Synergistic effect of KI on the corrosion inhibition of a poly(diallylammonium chloride)-based cyclocopolymer containing bis-cationic motifs for mild steel corrosion in 20% formic acid

This study entails the syntheses of a homopolymer, poly(diallylammonium chloride) (3), and copolymers (8a-c) containing hydrophilic/hydrophobic pendants and their role in mitigating mild steel in aggressive 20% formic acid, a type of corrosion that is not frequently discussed in the literature. The synthesized homopolymer and copolymers were characterized by FTIR, NMR, viscometry, and TGA. Inhibitor 8b was found to be the most potent, with 81.8% inhibition efficiency (IE) registered via the potentiodynamic polarization method for 100 ppm of inhibitor concentration at 30 °C. Inhibitor 8b, mixed with 2 mmol KI, showed more than 90% IE for a meager 1 ppm inhibitor concentration. For a synergism of 50 ppm inhibitor and 2 mmol KI, the IE reached a high value of 99.1%. The synergism was so good that it helped the inhibitor retain ∼100% of its original IE even after a 24 h weight loss study at 60 °C. The adsorption isotherm study showed that 8b followed the Langmuir adsorption isotherm and adsorbed via chemisorption. A very high value (2.48 × 105 L mol-1) of the equilibrium adsorption constant (Kads) indicated strong adsorption. XPS and SEM surface studies provided evidence of the inhibitor found on the metal surface. Some toxicological parameters, such as LC50, bioaccumulation factor, and developmental toxicity, have been measured computationally. A brief mechanistic insight into how the inhibitors functioned has been offered along with the DFT study.

Utilizing birch leaf extract in pickling liquid as a sustainable source of corrosion inhibitor for pipeline steel

This study set out to determine the effectiveness of birch leaves extract (BLE) as a corrosion inhibitor against X52 pipeline steel in the pickling solution. Chemical and electrochemical techniques, as well as scanning electron microscope (SEM), Fourier-transform infrared (FT-IR), and adsorption isotherms were used in the research. Various triterpenoids, including betulin, betulinic acid, oleanolic acid, sitosterol, and kaempferol, are unquestionably involved in the corrosion inhibition mechanism, according to the high-performance-liquid-chromatography (HPLC) analysis. The 95% efficiency of the produced BLE extract (at optimum concentration 400 mg L^-1) significantly reduced the corrosion rate of X52 pipeline steel in the pickling solution. The adsorption of BLE extract molecules on the X52-steel surface was demonstrated by SEM and FT-IR analysis. The adsorption activity follows the Langmuir adsorption theory.

Newly Synthesized Morpholinyl Mannich Bases as Corrosion Inhibitors for N80 Steel in Acid Environment

New Mannich bases, 3-morpholino-1-phenylpropan-1-one (MPO) and 3-morpholino-1-phenyl-3-(pyridin-4-yl) propan-1-one (MPPO), were synthesized, characterized, and studied as corrosion inhibitors for N80 steel in 1 M hydrochloric acid (HCl) solution using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and FT-IR spectroscopy. The inhibition efficiency increases with increasing inhibitor concentrations, and the corrosion inhibition efficiency of the MPO and MPPO could reach 90.3% and 91.4%, respectively, at a concentration of 300 ppm at 305 K. The effect of the temperature on the corrosion inhibition behavior of inhibitors was discussed. Electrochemical tests showed that the synthesized inhibitors are mixed. The EIS test results showed that the presence of MPO and MPPO reduced the double-layer capacitance in the corrosion process, thereby reducing the charge transfer resistance. The SEM and EDX results showed that the MPO and MPPO formed a uniform adsorption film on the surface of the N80 steel. The adsorption mechanism of the inhibitors was simulated with different adsorption models and the results showed that the inhibitors were the chemisorbed type. The results of the FT-IR spectroscopy proved that the inhibitor interacted with metal atoms on the steel surface.

Corrosion Inhibition in Acidic Environments: Key Interfacial Insights with Photoelectron Spectroscopy

In many engineering scenarios, surface-active organic species are added to acidic solutions to inhibit the corrosion of metallic components. Given suitable selection, such corrosion inhibitors are highly effective, preventing significant...

The synergistic influence of polyethyleneimine-grafted graphene oxide and iodide for the protection of steel in acidizing conditions

Herein, graphene oxide (GO) was chemically functionalized with polyethyleneimine (PEI) in a single step to obtain PEI-GO, which was characterized via FTIR spectroscopy, SEM, and TEM. Additionally, for the first time, PEI-GO was employed for the corrosion mitigation of carbon steel in a solution of 15% HCl. The corrosion performance of the inhibitor was evaluated by utilizing weight loss tests, electrochemical measurements with impedance analysis, electrochemical frequency modulation, and potentiodynamic polarization studies. Thorough surface analysis was performed using 3D profilometry and static water contact angle measurements. PEI-GO was adsorbed on the steel surface and showed mixed-type corrosion inhibition behavior with the prevalence of cathodic characteristics. Additionally, potassium iodide was incorporated in the acid solution as a synergistic agent to enhance the corrosion inhibition behavior of PEI-GO. The obtained results showed that PEI-GO alone provided a high corrosion inhibition efficiency of 88.24% at a temperature of 65 °C and in the presence of KI, it showed an I.E. of 95.77% due to their synergistic effect. These interesting results demonstrate that PEI-GO can act as a potential corrosion inhibitor in acidizing conditions. The DFT-based computational studies showed that the inhibitor functioned in both its neutral and protonated forms.

Herein, graphene oxide (GO) was chemically functionalized with polyethyleneimine (PEI) in a single step to obtain PEI-GO, which was characterized via FTIR spectroscopy, SEM, and TEM.

The Synergistic Impact of the Aqueous Valerian Extract and Zinc Ions for the Corrosion Protection of Mild Steel in Acidic Environment

Herein, the corrosion inhibition performance of mild steel (MS) in an acidic environment (1.0 M HCl) by the valerian extract has been studied via weight loss method (WL), potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. The results illustrated that the inhibition efficiency, raised by the rise of the extract concentrations. The inhibitory mechanism depended on the creation of a stable plant extract-complex on the mild steel surface. Polarization studies confirmed that the extract behaved as a mixed type inhibitor. The corrosion inhibition was supposed to exist via adsorption of the main components of the valerian extract. Attenuated total reflection-infrared spectroscopy (ATR-IR), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were applied to investigate the change in the surface morphology and confirmed the corrosion inhibition mechanism. The complete study confirmed that the efficiency of the valerian extract as a safe, eco-friendly and exchange corrosion inhibition for mild steel in an acidic environment.

Adsorption and corrosion inhibition behaviour of new theophylline-triazole-based derivatives for steel in acidic medium

The design and synthesis of a series of theophylline derivatives containing 1,2,3-triazole moieties are presented. The corrosion inhibition activities of these new triazole-theophylline compounds were evaluated by studying the corrosion of API 5 L X52 steel in 1 M HCl medium. The results showed that an increase in the concentration of the theophylline-triazole derivatives also increases the charge transference resistance (R ct) value, enhancing inhibition efficiency and decreasing the corrosion process. The electrochemical impedance spectroscopy under static conditions studies revealed that the best inhibition efficiencies (approx. 90%) at 50 ppm are presented by the all-substituted compounds. According to the Langmuir isotherm, the compounds 4 and 5 analysed exhibit physisorption-chemisorption process, with exception of the hydrogen 3, bromo 6 and iodo 7 substituted compounds, which exhibit chemisorption process. The corrosion when submerging a steel bar in 1 M HCl was studied using SEM-EDS. This experiment showed that the corrosion process decreases considerably in the presence of 50 ppm of the organic inhibitors. Finally, the theoretical study showed a correlation between EHOMO, hardness (η), electrophilicity (W), atomic charge and the inhibition efficiency in which the iodo 7 substituted compound presents the best inhibitor behaviour.

Electrochemical study of commercial and synthesized green corrosion inhibitors for N80 steel in acidic liquid

The present paper deals with the investigation of two synthesized benzimidazole derivatives (BZs) as corrosion inhibitors for N80 steel under static conditions in a 15% HCl corrosive environment and in the temperature range of 30 to 90 °C.

Comprehensive investigations on the action of cationic terthiophene and bithiophene as corrosion inhibitors: experimental and theoretical studies

A modified form of a naturally occurring α-terthienyl compound as a highly efficient corrosion inhibitor used at a very low dose.

Matrix acidizing: a fouling mitigation process in oil and gas wells

Fouling mitigation in underground reservoirs enhances the permeability and the flow capacity of production or injection wells and is carried out by reservoir stimulation methods such as matrix acidizing. This process is known as the most significant method used to improve the production or injection indices of oil and gas wells as well as water and steam wells. Here, different aspects of this process, its chemical advances and novel high-technologies are compared and discussed in order to reveal their advantages and determine under what conditions they are applicable. Knowledge for adapting the proper acid treatment with the well characteristics is another issue that has been considered in this paper. The final goal is to present the state-of-the-art fouling mitigation methods based on novel experiments, simulations and investigations in order to emphasize the engineering aspects of fouling mitigation in oil and gas wells by matrix acidizing.

Corrosion inhibition of mild steel in 1M HCl by D-glucose derivatives of dihydropyrido [2,3-d:6,5-d'] dipyrimidine-2, 4, 6, 8(1H,3H, 5H,7H)-tetraone

D-glucose derivatives of dihydropyrido-[2,3-d:6,5-d']-dipyrimidine-2, 4, 6, 8(1H,3H, 5H,7H)-tetraone (GPHs) have been synthesized and investigated as corrosion inhibitors for mild steel in 1M HCl solution using gravimetric, electrochemical, surface, quantum chemical calculations and Monte Carlo simulations methods. The order of inhibition efficiencies is GPH-3 > GPH-2 > GPH-1. The results further showed that the inhibitor molecules with electron releasing (-OH, -OCH3) substituents exhibit higher efficiency than the parent molecule without any substituents. Polarization study suggests that the studied compounds are mixed-type but exhibited predominantly cathodic inhibitive effect. The adsorption of these compounds on mild steel surface obeyed the Langmuir adsorption isotherm. SEM, EDX and AFM analyses were used to confirm the inhibitive actions of the molecules on mild steel surface. Quantum chemical (QC) calculations and Monte Carlo (MC) simulations studies were undertaken to further corroborate the experimental results.