Mixed-type Inhibitor Research Articles

Dehydroabietylamine derived bistetrazoles from ultrasound-assisted pseudo-seven-component Ugi reactions act as efficient and selective inhibitors of cholinesterases

The reaction of dehydroabiethylamine (DHA) with isocyanides and formaldehyde produces varying products depending on the conditions employed. In a 4-component Ugi reaction using benzyl isocyanide, paraformaldehyde, and TMS-azide, the anticipated tetrazole is formed. Nevertheless, other isocyanides were unsuccessful in these conditions. Upon substituting paraformaldehyde with formalin and utilizing ultrasound instead, bis-tetrazole formation was obtained in a pseudo-7-component reaction. A bis-benzyl-substituted tetrazole 5 demonstrated significant AChE and BChE inhibition in Ellman's assays. Molecular modeling corroborated these results, with compound 5 identified as a mixed-type inhibitor for both enzymes.

Electrochemical, spectroscopic, kinetic and surface analysis of the inhibitory performance of Alcian blue dye for copper corrosion in sulfuric acid solution

The use of corrosion inhibitors is considered as the supreme dominant approach to control the damage of metallic corrosion. Organic dyes are extensively employed as inhibitors for the corrosion of various metals and alloys in diverse media. Herewith, Alcian blue dye (ABD) was selected to investigate its inhibitive characteristics against the corrosion of copper in 1.0 M H2SO4 solution at 298 K. This investigation was monitored by various chemical, electrochemical, and spectroscopic techniques. The results indicated that the examined dye is a proficient inhibitor for the corrosion of copper in 1.0 M H2SO4 solution and its inhibition efficiency (% IE) was increased with augmenting its concentration and diminished with rising medium temperature. The high anti-corrosive ability of the selected dye was attributed to its adherent adsorption of such dye on the Cu surface and follows Langmuir isotherm. Thermodynamics and kinetics of corrosion of copper and its inhibition by the examined dye were inspected. The mechanisms of copper corrosion in H2SO4 solution and its inhibition by ABD were proposed. The obtained results illuminated that the examined dye acts as a mixed-type inhibitor with cathodic precedence. Finally, all gained results with respect to % IE values of the dye were compared and designated a good harmony between all applied techniques.

New 3-amino-2-thioxothiazolidin-4-one-based inhibitors of acetyl- and butyryl-cholinesterase: synthesis and activity.

Aim: 2-Thioxothiazolidin-4-one represents a versatile scaffold in drug development. The authors used it to preparenew potent acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors that can be utilized, e.g., to treat Alzheimer's disease. Materials & methods: 3-Amino-2-thioxothiazolidin-4-one was modified at the amino group or active methylene, using substituted benzaldehydes. The derivatives were evaluated for inhibition of AChE and BChE (Ellman's method). Results & conclusion: The derivatives were obtained with yields of 52-94%. They showed dual inhibition with IC50 values from 13.15μM; many compounds were superior to rivastigmine. The structure-activity relationship favors nitrobenzylidene and 3,5-dihalogenosalicylidene scaffolds. AChE was inhibited noncompetitively, whereas BChE was inhibited with a mixed type of inhibition. Molecular docking provided insights into molecular interactions. Each enzyme is inhibited by a different binding mode.

Selenocyanates and selenotetrazoles derivatives: A detailed experimental and theoretical evaluation as corrosion inhibitors for mild steel in aggressive environment

This work presents the selenocyanates ESCA and ESCP and their derivatives selenotetrazoles ETSP and ETSA, which were synthesized with good to excellent yields. The compounds were designed and studied as corrosion inhibitors for mild steel in 1 mol L−1 HCl. Weight loss experiments showed that ESCP, ESCA, ETSP, and ETSA mitigate corrosion from 81.1 to 92.8 % at 2.00 mmol L−1 (298 K). At higher temperatures (338 K), those values go from 85 to 95 %. EIS shows that the mechanism of corrosion is by charge transfer and that the organic compounds act by adsorbing in the surface and blocking the active sites. Polarization curves and EFM prove that the corrosion density is significantly lower in the presence of the four molecules, and they all are mixed-type corrosion inhibitors. AFM depicted the topography of the metallic surface and point to the formation of an adsorbed protective film. Atomistic simulations using ab initio DFT were employed to investigate the interactions between selenocyanates and selenotetrazoles with an Fe(110) metal surface, elucidating the adsorption geometries and electronic properties. Our findings demonstrated that the adsorption geometries and resultant bonds, particularly those involving oxygen (O), selenium (Se), and nitrogen (N) atoms, critically influence the corrosion inhibition capabilities of these molecules. ESCA and ETSP showed bond rupture of C-Se while ESCP had no covalent bonding with iron atoms, which can explain their lower inhibitive performance compared to more energetically stable ETSA.

Experimental and theoretical investigation of spiro heterocyclic compound as potential inhibitor for mild steel in acid media

The corrosion inhibition performance of spiropyrazoline was explored for mild steel corrosion in 1M HCl and 0.5M H2SO4 using weight loss, potentiodynamic polarization and electrochemical impedance studies. Inhibition efficiency of the inhibitor increased with increase in concentration within the range of 1–9 ppm. Spiropyrazoline inhibitor showed better inhibition performance of 92.6 %, 97.7 % in 1 M HCl and 0.5 M H2SO4, respectively at 9 ppm concentration by forming protective film on the metallic surface. Electrochemical impedance spectroscopy analysis (EIS) revealed an increase in polarization resistance due to the adsorbed inhibitor molecules. Potentiodynamic polarization analysis reveals that spiropyrazoline behaved as a mixed type inhibitor. The adsorption of the inhibitor on the metal surface found to obeying Langmuir and Temkin adsorption isotherm at room temperature. Surface morphology of the protective layer was examined by FTIR, scanning electron microscopy and atomic force microscopy. The inhibition mechanism of the inhibitor molecule was proposed in the light of the quantum chemical calculations using DFT.

Identification of non-steroidal aromatase inhibitors via in-silico and in-vitro studies.

Breast cancer is the most common cancer affecting women worldwide, including Pakistan. More than half of breast cancer patients have hormone-dependent breast cancer, which is developed due to the over-production of estrogen (the main hormone in breast cancer). The biosynthesis of estrogen is catalyzed by the aromatase enzyme, which thus serves as a target for the treatment of breast cancer. During the current study, biochemical, computational, and STD-NMR methods were employed to identify new aromatase inhibitors. A series of phenyl-3-butene-2-one derivatives 1-9 were synthesized and evaluated for human placental aromatase inhibitory activity. Among them, four compounds 2, 3, 4, and 8 showed a moderate to weak inhibitory activity (IC50 = 22.6 - 47.9 µM), as compared to standard aromatase inhibitory drugs, letrozole (IC50 = 0.0147 ± 1.45 µM), anastrozole (IC50 = 0.0094 ± 0.91 µM), and exemestane (IC50 = 0.2 ± 0.032 µM). Kinetic studies on two moderate inhibitors, 4 and 8, revealed a competitive- and mixed-type of inhibition, respectively. Docking studies on all active compounds indicated their binding adjacent to the heme group and interaction with Met374, a critical residue of aromatase. STD-NMR further highlighted the interactions of these ligands with the aromatase enzyme. STD-NMR-based epitope mapping indicated close proximity of the alkyl chain followed by an aromatic ring with the receptor (aromatase). These compounds were also found to be non-cytotoxic against human fibroblast cells (BJ cells). Thus, the current study has identified new aromatase inhibitors (compounds 4, and 8) for further pre-clinical and clinical research.

An exploratory assessment supported by experimental and modeling approaches for dinitrophenylhydrazine compound as a potent corrosion inhibitor for carbon steel in sulfuric acid solution

Comprehensive electrochemical and theoretical investigations were conducted to assess the effectiveness of 2, 4-Dinitrophenylhydrazine (DNPH) as a corrosion inhibitor for carbon steel (CS) immersed in a 0.5 M H2SO4 solution. The results demonstrated significant corrosion inhibition efficiency of DNPH, reaching an impressive rate of 88 % at a concentration of 10−3 M. Polarization analysis revealed DNPH's role as a mixed-type inhibitor. Furthermore, the study elucidated that DNPH adsorption on the CS surface followed the Langmuir adsorption model, with a mechanism attributed to specific physical interactions. Scanning electron microscope (SEM) observations of both treated and untreated samples confirmed DNPH's efficacy in protecting carbon steel in a 0.5 M H2SO4 environment. Quantum chemical calculations using Density Functional Theory (DFT) parameters, in conjunction with molecular dynamics simulations, provided theoretical data strongly correlated with experimental results.

Exploring the interaction of phytochemicals from Hibiscus rosa-sinensis flowers with glucosidase and acetylcholinesterase: An integrated in vitro and in silico approach

Targeting multiple factors such as oxidative stress, alpha glucosidase and acetylcholinesterase (AChE) are considered advantageous for the treatment of diabetes and diabetes associated-cognitive dysfunction. In the present study, Hibiscus rosa-sinensis flowers anthocyanin-rich extract (HRA) was prepared. Phytochemical analysis of HRA using LC-ESI/MS/MS revealed the presence of various phenolic acids, flavonoids and anthocyanins. HRA showed in vitro antioxidant activity at low concentrations. HRA inhibited all the activities of mammalian glucosidases and AChE activity. The IC50 value of HRA for the inhibition of maltase, sucrase, isomaltase, glucoamylase and AChE was found to be 308.02 ± 34.25 µg/ml, 287.8 ± 19.49 µg/ml, 424.58 ± 34.75 µg/ml, 408.94 ± 64.82 µg/ml and 264.13 ± 30.84 µg/ml, respectively. Kinetic analysis revealed mixed-type inhibition against all the activities except for glucoamylase (competitive) activity. In silico analysis confirmed the interaction of two active constituents cyanidin 3-sophoroside (CS) and quercetin 3-O-sophoroside (QS) with four subunits, n-terminal and c-terminal subunits of human maltase-glucoamylase and sucrase-isomaltase as well as with AChE. Molecular dynamics simulation, binding free energy calculation, DCCM, PCA, PCA-based free energy surface analysis ascertained the stable binding of CS and QS with target proteins studied. HRA could be used as complementary therapy for diabetes and cognitive improvement.

Comprehensive investigation of sustainable corrosion inhibitors on Cu–Zn alloy in simulated cooling water: Electrochemical explorations, SEM/EDX analysis, and DFT/molecular simulations utilizing expired Bepotastine-B as a green inhibitor

In terms of green chemistry, the use of the use of expired drugs has recently gained attention as sustainable corrosion inhibitors due to their biodegradability, environmental friendliness, low cost, and easy availability. This paper aimed to evaluate the protective action of expired Bepotastine-B on Cu–Zn alloy in simulated cooling water (SCW) using weight loss (WL), Potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), surface morphology analysis and computer modeling methods, including density functional theory (DFT) and molecular dynamic simulations (MS).The variables concentration, reaction temperature, and pH of an expired drug were examined. The electrochemical results demonstrated that the expired Bepotastine-B is a mixed-type inhibitor that blocks both the anodic and cathodic potentials, which exhibited high inhibition. The corrosion rate falls as the Bepotastine increases and increases as the temperature rises. The drug's adsorption on Cu–Zn alloy follows the Langmuir isotherm model. The examination of surface morphology (SEM/EDX) indicated a formation of an insoluble complex and a fine film of inhibitor, which effectively hinders Cu–Zn alloys from deteriorating, covering the surface. These findings confirmed the formation of an adsorbed layer by the Bepotastine-B molecules hindered the dissolving of Cu–Zn alloys. The inhibitory impact of Bepotastine-B, which investigated, theoretically using DFT and the computational results align well with the results obtained from experimental inhibition efficiencies. The inhibition efficiency (IE) improved with raising Bepotastine-B concentration. The maximum IE of 94.6% has been achieved at 300 mg/L. The combination of experimental and computational approaches enhanced our understanding of the corrosion inhibition mechanism and underscored the potential of Bepotastine-B as a sustainable, and effective corrosion inhibitor for Cu–Zn alloy in this medium at dissimilar temperatures. These findings can serve as a useful guideline for future research aimed at investigating the inhibitory impact of expired drugs as a green one.

Hybrid epoxy/Br inhibitor in corrosion protection of steel: experimental and theoretical investigations.

The corrosion of carbon steel infrastructure in acidic environments poses significant economic and safety challenges. Traditional inhibitors such as chromates are being phased out due to toxicity concerns. Thus, there is a need to develop effective and sustainable green alternatives. In this work, we evaluated an epoxy-based inhibitor, bisphenol A tetrabromo dipropoxy dianiline tetraglycidyl ether (TGEDADPTBBA), for protecting carbon steel against corrosion in 1M hydrochloric acid. An integrated experiment-computation approach was employed. Polarization curves and electrochemical impedance spectroscopy were used to assess the inhibition efficiency and mechanism of TGEDADPTBBA. Quantum chemical calculations and molecular dynamics simulations provided atomic-level insights into adsorption behavior. Scanning electron microscopy with energy-dispersive X-ray spectroscopy characterized the surface morphology. The results showed that TGEDADPTBBA acted as a highly effective mixed-type inhibitor, achieving over 95% inhibition efficiency at a 10-3M concentration. It suppressed corrosion currents while increasing the charge transfer resistance. Theoretical studies revealed that TGEDADPTBBA adsorbed onto steel surfaces via both electrostatic and van der Waals interactions. This stable adsorption facilitated the formation of a protective barrier layer, as observed experimentally. Notably, our work demonstrated the synergistic potential of combining experimental corrosion testing with computational modeling to develop structure-property relationships for innovative inhibitor design. This integrated approach offers insight into inhibition mechanisms and presents TGEDADPTBBA as an attractive green corrosion inhibitor alternative for industrial applications.

Electrochemical and theoretical investigations to comprehend the adsorption of new pyrazole derivative on mild steel in 1 M HCl

The adsorption performance of 4-((1H-pyrazol-1-yl)methyl)-4-methyl-2-phenyl-4,5-dihydrooxazole [Pyr-H2] and 4-((3,5-dimethyl-1H-pyrazol-1-yl)methyl)-4-methyl-2-phenyl-4,5-dihydrooxazole [Pyr-(CH3)2] was evaluated for mild steel in 1 M HCl solution. The current examination was carried out using weight loss measurements, electrochemical techniques (polarization curves and electrochemical impedance spectroscopy), surface morphology analysis, and theoretical approach. Before the experimental test, in-silico environmental toxicity was evaluated, indicating the eco-friendly behavior of the concentration used as corrosion inhibitors. The experimental findings showed that these chemicals acting as mixed-type inhibitors, preventing both anodic and cathodic reactions. Moreover, the mild steel surface was also examined using scanning electron microscopy coupled with EDX analysis. These chemicals adsorbed onto the mild steel surface following Langmuir isotherm. In addition, DFT calculations at B3LYP 6-311G (d,p) was used to estimate the reactivity of these molecules by linking their electronic characteristics with their experimental outcomes, whereas Monte Carlo simulation confirms the parallel approach of the studied pyrazole into the steel surface. Finally, it can be concluded that the existence of two methyl group in [Pyr-(CH3)2] inhibitor augmented the covered surface area compared to [Pyr-H2] molecule.

Corrosion Inhibition Mechanism of Water-Soluble Imidazoline on A572 Gr.65 Steel in 3.5 wt % NaCl Solution.

To optimize the economic advantages and corrosion-resisting property of A572 Gr.65 steels, the inhibition effect of water-soluble imidazoline on the sample surface with rare earth was explored in a 3.5 wt % NaCl solution. In this paper, the mechanism of corrosion and the adsorptive behavior of water-soluble imidazoline inhibitors on A572 Gr.65 steels with 47 ppm of rare earth in saltwater solution were discussed, along with the establishment of the adsorption model. Achievements proposed that the inhibition efficiency of water-soluble imidazoline was as high as 95.73% at 80 mg L-1 dosage following an anodic-dominated mixed-type inhibition mechanism. Besides, the scanning electron microscopy and X-ray diffraction analysis revealed that the corrosion inhibitor resulted in a smoother and more stable rust layer with a significant reduction of the γ-FeOOH. Theoretical calculations confirmed that imidazoline formed a unimolecular layer adsorption film on the steel surface, exhibiting adherence to both Langmuir and Frumkin adsorption isotherms, involving physical and chemical adsorption.

Identification of Novel -Glucosidase Inhibitors from Syzygium jambos (L.) Using Spectroscopy and Molecular Docking.

Fruits ofSyzygiumjambos(L.) are recognized as a "food", exhibiting significant antidiabetic activities. However, the α-glucosidase inhibition of the components from Syzygiumjambos(L.) have not yet been investigated. In this study,a total of 14 compounds were isolated from Syzygium jambos (L.) Alston, eight of which showed significant inhibitory effects on α-glucosidase, with IC50 values in the range of 0.011-0.665mM. Notably, compounds 1-3 (IC50: 0.013, 0.011 and 0.030mM, respectively) exhibited much stronger activity than acarbose (IC50: 2.329 ± 0.109mM). The enzyme kinetics study indicated that compound 1 was an uncompetitive inhibitor, and compounds 2-8 were mixed-type inhibitors. Moreover, the interactions between compounds and α-glucosidase were investigated by molecular docking, which further revealed that the number of olefin double bonds and 2-COOH of heptadeca-phenols had a notable effect on the α-glucosidase inhibitory activity. This study demonstrated that Syzygiumjambos(L.) fruit might serve as a functional food for the prevention of diabetes mellitus.

Modified nano-lignin as a novel biomass-derived corrosion inhibitor for enhanced corrosion resistance of carbon steel

Methacryloyloxyethyl trimethyl ammonium chloric modified nano-lignin corrosion inhibitor (DMC-NL) is prepared and firstly applied as a novel biomass-derived corrosion inhibitor for carbon steel in HCl solution. Nanosizing and modification processes can enhance its anticorrosion ability, the corrosion inhibition efficiency increases with additive amount and can reach 95.3 ± 0.9% for 15 mg/L. DMC-NL is belonging to the mixed-type corrosion inhibitor and its anti-corrosion ability gradually increases with immersion time. The dense film with two-tier structure forms on metal surface by interactions between N and Fe atoms. This work provides the new insight and opportunity of development of biomass-derived eco-friendly corrosion inhibitor.

Polyphenol Composition, Antioxidant Capacity and Xanthine Oxidase Inhibition Mechanism of Furong Plum Fruits at Different Maturity Stages.

An experiment was conducted on the polyphenol content, flavonoid content, anthocyanin content, and antioxidant capacity of Furong plum (Prunus salicina Lindl. cv. "furong") at different maturity stages to determine the most suitable maturity stage. The inhibition of plum polyphenols on xanthine oxidase (XOD) was measured, and its kinetics were studied to reveal the inhibitory mechanism. The experimental results showed that the polyphenol, flavonoid and anthocyanin contents of plums at the ripe stage were the highest, reaching 320.46 mg GAE/100 g FW, 204.21 mg/100 g FW, and 66.24 mg/100 g FW, respectively, in comparison those of the plums at the immature and mid-ripe stages. The antioxidant capacity of the ripe plums was stronger than it was during the other stages of the plums growth. Among them, the total polyphenols of the ripe plums exhibited the strongest antioxidant capacity (IC50 values against DPPH and hydroxyl radicals were 28.19 ± 0.67 μg/mL and 198.16 ± 7.55 μg/mL, respectively), which was between the antioxidant capacity of the free polyphenols and bound polyphenols. The major phenolic monomer compounds of plum polyphenols were flavan-3-ols (epicatechin, catechin, proanthocyanidin, and procyanidin B2), flavonols (myricetin), and phenolic acids (chlorogenic acid, ferulic acid, and protocatechuic acid). Additionally, plum polyphenols exhibited a strong inhibitory effect on XOD, with an IC50 value of 77.64 μg/mL. The inhibition kinetics showed that plum polyphenols are mixed-type inhibitors that inhibit XOD activity and that the inhibition process is reversible. The calculated values of Ki and α were 16.53 mmol/L and 0.26, respectively.

Investigation into the impact of proton pump inhibitors on sertraline transport across the blood-brain barrier

As a widely used antidepressant that works by inhibiting the reuptake of serotonin, sertraline exerts an antidepressant effect depending on its concentration in the brain, which might be limited by the blood-brain barrier (BBB). It is highly possible to combine proton pump inhibitors (PPIs) with sertraline in clinical trials. Nevertheless, the role played by PPIs in regulating the transport of sertraline across the BBB remains unclear. Here, the impact of PPIs on the distribution of sertraline in the brain and the mechanisms involved were investigated. A mouse brain distribution study showed that Omeprazole (OME), Pantoprazole (PAN), Ilaprazole (ILA), and Esomeprazole (ESO) increased the area under the brain concentration-time curves (AUC) for sertraline by 2.02-, 3.18-, 3.04-, and 4.21-fold, respectively, after the 14-day administration of PPIs. Besides, PPIs significantly increased the permeability of sertraline in brain perfusion experiments, with PAN having the highest rank order, followed by ILA, OME, and ESO. In the tail suspension test (TST), co-administration PPI groups showed significantly shorter immobility time than the control group. In vitro, four PPIs inhibited sertraline efflux in breast cancer resistance protein (BCRP)-overexpressing MDCKII cells, and showed a mixed inhibition type. In this study, PPIs were further found to inhibit the mRNA and protein expression of brain BCRP. To sum up, the findings of this study revealed that PPIs could enhance the brain distribution and antidepressant effect of sertraline, which may be attributed to the inhibition of BCRP expression at the BBB by PPIs.

New chromone derivatives bearing thiazolidine-2,4-dione moiety as potent PTP1B inhibitors: Synthesis and biological activity evaluation

A series of chromone derivatives bearing thiazolidine-2,4-dione moiety (5 ∼ 37) were synthesized and evaluated for their PTP1B inhibitory activity, interaction analysis and effects on insulin pathway in palmitic acid (PA)-induced HepG2 cells. The results showed that all derivatives presented potential PTP1B inhibitory activity with IC50 values of 1.40 ± 0.04 ∼ 16.83 ± 0.54 μM comparing to that of positive control lithocholic acid (IC50: 9.62 ± 0.14 μM). Among them, compound 9 had the strongest PTP1B inhibitory activity with the IC50 value of 1.40 ± 0.04 μM. Inhibition kinetic study revealed that compound 9 was a reversible mixed-type inhibitor against PTP1B. CD spectra results confirmed that compound 9 changed the secondary structure of PTP1B by their interaction. Molecular docking explained the detailed binding between compound 9 and PTP1B. Compound 9 also showed 19-fold of selectivity for PTP1B over TCPTP. Moreover compound 9 could recovery PA-induced insulin resistance by increasing the phosphorylation of IRSI and AKT. CETSA results showed that compound 9 significantly increased the thermal stability of PTP1B.

Expired butamirate drug as eco-friendly corrosion inhibitor for aluminum in seawater: Experimental and theoretical studies

In this work, an expired butamirate drug (EBD) was used as a corrosion inhibitor for aluminum in artificial seawater (3.5% NaCl solution). The corrosion rate was evaluated as a function of temperature and inhibitor concentrations using the electrochemical polarization technique. These data indicated that the EBD acts as a mixed-type corrosion inhibitor with a slight effect on the cathodic reaction. Corrosion current densities increased with temperature and decreased with inhibitor concentration. At a temperature of 328 K and an inhibitor concentration of 24 ml/l, the maximum corrosion inhibition efficiency was 84.4%. The cyclic polarization test confirmed the greater pitting resistance in the presence of butamirate drugs in solution. Adsorption studies showed that EBD adsorbed chemically on the metal surface following the Langmuir adsorption isotherm. Electronic microscopy showed enhancements in the surface morphology in the presence of EBD. While FTIR was used for the diagnosis of functional groups in EBD and surface corrosion products. In addition, theoretical quantum chemical calculations were used as a powerful tool to support the experimental studies.

Inhibition behavior of new ecological corrosion inhibitors for mild steel, copper and aluminum in acidic environment: Theoretical and experimental investigation

It is well known that the most practical approach to prevent metal from their degradation when it is in contact with aggressive solution is the application of inhibitors. The present work was designed to evaluate the inhibition behavior and the adsorption process of (E)‑1‑(5‑methylfuran‑2‑yl)‑3‑(6‑phenylimidazo[2,1‑b]thiazol‑5‑yl)prop‑2‑en‑1‑one (MF-PIT) for various metals (Copper (Cu), Mild steel (MS), and Aluminum (Al)) in 1 M HCl using electrochemical techniques, surface analysis characterization, and theoretical approaches. Firstly, DFT calculations and molecular dynamic simulation were executed to explore the reactivity of the studied inhibitor, and the adsorption configuration indicated in each metal. Before the experimental test, the environmental toxicity was evaluated and confirmed the safety of using the studied concentration. PDP results showed a good inhibition performance with inhibition efficiency of around 97.5% for copper, 95.9% for Mild steel, and 92.2% for Aluminum at the optimum concentration of 10−4 M. These results confirmed the EIS experiments and revealed that MF-PIT acted as a mixed-type inhibitor for the three metals. The adsorption of MFPIT obeyed the Langmuir isotherm model and form a strong bond with the studied metallic samples. The inhibition performance of MF-PIT showed a good correlation with the theoretical finding.

Investigation of the mechanisms and adsorption of a new pyrazole derivative against corrosion of carbon steel in hydrochloric acid solution: Experimental methods and theoretical calculations

In an electrolyte of hydrochloric acid (1 M HCl) at 303 K, the effectiveness of the pyrazole derivative N,N,N′,N′-tetrakis((3,5-dimethyl-1 H-pyrazol-1-yl)methyl)pyridine-2,6-diamine (PRPD) as a corrosion inhibitor was examined. Several experimental methods, such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), surface morphology analysis (SEM) coupled with energy dispersive X-ray analysis (EDX), AFM, contact angle (CA), FTIR, X-ray photoelectron spectroscopy (XPS), UV–visible, and X-ray diffraction (XRD), were used to conduct the measurements. To support these experimental findings, we use theoretical calculations such as density functional theory (DFT) and molecular dynamics (MD) simulations. The achieved findings manifested that the PRPD behaves as a powerful corrosion inhibitor, achieving an anti-corrosion performance of 97.2% at 0.001 M. The PDP technique suggests that PRPD is part of a mixed-type inhibitor. The PRPD molecules are chemisorbed at the carbon steel (CS) surface in accordance with the Langmuir isotherm model. On the ground of surface analysis, the build-up of an adsorptive layer inhibitor on the steel surface has been verified. DFT and MD simulation analyses have validated the experimental findings. These results contribute to the creation of successful corrosion control methods by providing insightful information about the inhibition of carbon steel corrosion in a 1 M HCl environment.