Adsorption and inhibition effect of 6-benzylaminopurine on cold rolled steel in 1.0M HCl

Density functional theory study of the corrosion inhibition performance of 6-mercaptopurine and 6-thioguanine expired drugs toward the aluminium (111) surface

The potentiality of the 6-mercaptopurine (MP) and 6-thioguanine (TG) expired drugs toward the corrosion inhibition of the aluminium (Al) (111) surface was widely investigated using a series of density functional theory (DFT) calculations. A competition between the anti-corrosive features of the studied drugs in the gas and aqueous phases was conducted on both neutral and protonated forms by means of quantum mechanical descriptors. The results of the electrostatic potential analysis demonstrated the prominent nucleophilic nature of the sulfur and nitrogen atoms over the structures of the examined drugs. The frontier molecular orbital theory findings outlined the higher preferability of TG over MP as a corrosion inhibitor. Upon determining the most beneficial configurations of the MP/TG⋯Al (111) complexes, first-principles molecular dynamics simulations were executed. Interestingly, the competence of the TG drug in the corrosion inhibition process of Al (111) was more extensive than that of the MP one, which was confirmed by the interaction energy values of -1.79 and -1.64 eV, respectively. Upon obtaining the relaxed complexes, the effect of the presence of water solvent on the adsorption process was studied. These findings provide a foundation for developing green anti-corrosive inhibitors for the aluminium surface.

Tailoring epoxy coating with acetoxime derivative of zinc for advanced anticorrosive performance on mild steel: experimental and computational insights

CONTEXT

In this work, the corrosion inhibitive effect of acetoxime derivative of zinc chloride, (ZnCl2.2HON=C(CH3)2) (ZA), was investigated on mild steel in epoxy/polyamide coating. ZA was used to modify diglycidyl ether of bisphenol A (DGEBA) to yield novel anticorrosive coating (epoxy-ZA) with excellent barrier characteristic. The dispersal of ZA may lead to the formation of Zn-O-C and O-Zn-O linkages in the polymer framework which act as inorganic fillers producing a dense structure of hybrid coating. In electrochemical findings, electrochemical impedance spectroscopy (EIS) and Tafel polarization (TP) indicate higher protection efficiency for epoxy-ZA coatings (99.99 and 99.93 % for EIS and TP, respectively) as compared to others. Using surface analysis and electrochemical data, it was concluded that an inhibition synergy was developed when ZA was taken instead of acetoxime or zinc chloride (ZC) alone in the coating formulation.

METHODS

Fourier transform infrared (FT-IR) was used to investigate epoxy interaction with zinc compounds and scanning electron microscopy (SEM) was used to investigate morphology of the samples. To reinforce the experimental results, reactivity of crosslinked epoxy and epoxy-ZA coatings with metallic surface was also explored using density functional theory (DFT) with basis set B3LYP/6-311G(d,p) and molecular dynamics (MD) methods by using Forcite module. Modification of epoxy with ZA enhances its interaction with steel surface in dry as well as in wet conditions as indicated by the adhesion energy calculated by MD simulations.

Experimental and Theoretical Tests on the Corrosion Protection of Mild Steel in Hydrochloric Acid Environment by the Use of Pyrazole Derivative

In this study, 1,5-diallyl-1H-pyrazolo [3,4-d] pyrimidin-4 (5H)-one (PPD) was evaluated as an anticorrosion agent for mild steel (MS) in 1 M HCl. The analysis was performed by weight loss (WL), potentiodynamic polarization measurement, and electrochemical impedance spectroscopy (EIS). The Tafel polarization showed that PPD is a mixed-type inhibitor and reaches 94% of the protective efficiency at 10^-3 M. EIS results indicated that the resistance to charge transfer increases with increasing inhibitor concentration and the corrosion of MS is controlled by a charge transfer process. The inhibitor adsorption on the MS surface obeyed the Langmuir's adsorption isotherm. Thermodynamic parameters were calculated to elaborate the corrosion inhibition mechanism. The micrographic analysis revealed the existence of a barrier layer on the electrode surface with the presence of PPD. Theoretical examinations performed by electronic/atomic computer simulations confirmed that the obtained results were found to be consistent with experimental findings.

Analysis of the protection of copper corrosion by using amino acid inhibitors

Since the human body is one of the highly aggressive environments, the materials utilized for an implant should have high resistance to degradation and corrosion. One of the commonly used biomaterials in medicine is copper (Cu). The Cu corrosion can result in the release of ions in the body with high toxicity, thereby causing inflammatory diseases. Based on the literature, as biomolecules, amino acids act as a corrosion inhibitor in aggressive solutions. The current work aims at scrutinizing the inhibition impact of L-arginine (L-Arg) and L-Valine (L-Val), which have been rarely investigated, upon the corrosion process of Cu. We undertook density functional theory computations to scrutinize the inhibitory impact of L-Arg and L-Val as well as their conformers upon Cu corrosion. Also, we scrutinized the computed parameters according to the back donation of electrons between Cu and the inhibitors, transported electron fraction, energy gap, softness, hardness, E_HOMO, and E_LUMO. According to the theoretical indices of L-Arg, it prefers adsorption. We examined the inhibitory efficiency of L-Arg against corrosion and found that it is a promising inhibitor.

Electronic sensors for alkali and alkaline earth cations based on Fullerene-C60 and silicon doped on C60 nanocages: a computational study

In this research, we have reported the electrical sensitivity of pristine C60 and silicon doped on C60 (SiC59) nanocages as sensors that can be used for detecting the presence of alkali (Li⁺, Na⁺, K⁺) and alkaline earth (Be²⁺, Mg²⁺, Ca²⁺) cations. The computations are carried out at the B3LYP level of theory with a 6-31G(d) basis set. The atoms in molecules (AIM) and natural bond orbital (NBO) analyses are performed to evaluate the intermolecular interactions between cations and nanocages. The physical properties of the selected complexes are also analyzed by the frontier molecular orbital, energy gap, electronegativity, chemical hardness, softness, and other quantities such as work function, number of transferred electron, and dipole moment. The results show that the adsorption process is exothermic and with increasing the charge of cations, the adsorption energies enhance. Our findings also reveal a decrease in the energy gap along with an increase in the electrical conductivity of the respective complexes. Finally, the density of state calculations is presented to confirm the obtained results.

Comparative data on corrosion protection of mild steel in HCl using two new thiazoles

This data article includes data described in the investigation report entitled “The synergistic role of azomethine group and triazole ring at improving the anti-corrosive performance of 2-amino-4-phenylthiazole” (Alamiery et al., 2021). In this data article, a comprehensive effect of 2-Amino-4-phenyl-N-benzylidene-5-(1,2,4-triazol-1-yl)thiazole (APNT) and 2-amino-4-phenylthiazole (APT) and optimized process parameter of the inhibitor in 1 M HCl solution was presented using gravimetric techniques and Density functional theory. The presence of the inhibitors influenced the corrosion resistance of mild steel (MS). Inhibition efficiencies values of 98.1% and 94.74% were recorded as results of inhibition of the MS by the inhibiting compounds APNT and ATP respectively. DFT studies observed that the presence of benzylidene to the APNT and the substitution of a triazole in the thiazole ring are adsorption sites that increase the interaction of the APNT molecules with the iron atoms on the MS surface.

Theoretical calculation of newly synthesized tetrazolopyrimidine derivatives as a potential corrosion inhibitor

In this work, we wanted to define a general and comprehensive strategy for the synthesis of tetrazolo[1,5-a]pyrimidine derivatives. For this purpose, we obtained new tetrazolo[1,5-a]pyrimidine molecules via the mercury-promoted desulfurization reaction, including hydrolysis, cyclizations, and eliminations. All of the molecules were characterized by FT-IR, 1H-NMR, 13C-NMR, and elemental analysis. On the other hand, the potentials of compounds as corrosion inhibitors were calculated at B3LYP/6-31G (d, p) level via density functional theory (DFT).

An Overview on the Performance of 1,2,3-Triazole Derivatives as Corrosion Inhibitors for Metal Surfaces

This review accounts for the most recent and significant research results from the literature on the design and synthesis of 1,2,3-triazole compounds and their usefulness as molecular well-defined corrosion inhibitors for steels, copper, iron, aluminum, and their alloys in several aggressive media. Of particular interest are the 1,4-disubstituted 1,2,3-triazole derivatives prepared in a regioselective manner under copper-catalyzed azide-alkyne cycloaddition (CuAAC) click reactions. They are easily and straightforwardly prepared compounds, non-toxic, environmentally friendly, and stable products to the hydrolysis under acidic conditions. Moreover, they have shown a good efficiency as corrosion inhibitors for metals and their alloys in different acidic media. The inhibition efficiencies (IEs) are evaluated from electrochemical impedance spectroscopy (EIS) parameters with different concentrations and environmental conditions. Mechanistic aspects of the 1,2,3-triazoles mediated corrosion inhibition in metals and metal alloy materials are also overviewed.

The Influence of Anion Structure on the Ionic Liquids/Au (100) Interface by Molecular Dynamics Simulations

The microstructure of electrical double layers (EDLs) of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF₄), 1-butyl-3-methylimidazoliumhexafluorophosphate ([Bmim]PF₆), and 1-butyl-3-methylimidazoliumbis (trifluoromethylsulfonyl) imide ([Bmim]TFSI) were studied by quantum chemical calculation and molecular dynamics simulation. For the set of ionic liquids investigated here, we found some interesting universal laws due to differences geometry and electronic structure of anions. We show that the morphology of the three anions on the electrode surface is different due to the different geometric structure. The plane formed by the bottom three atoms of the symmetrically tetrahedral BF₄^- and the bottom atom of the symmetrically octahedral PF₆^- face the electrode whether the electrode is charged or not, while the conformation of twisted V-shaped TFSI^- changes with different surface charges on the electrode. Meanwhile, we also demonstrate that the energy of highest occupied molecular orbital (E_HOMO), the energy of lowest unoccupied molecular orbital (E_LUMO) and their energies gap (ΔE) are very interesting due to different electronic structure of anions. Specially, the E_HOMO, E_LUMO, and ΔE were related to the electronegativity of the central atom in the case of the same symmetry on the neutral surface. The more electronegative the central atom is, the lower E_HOMO, E_LUMO and higher ΔE values are. However, on the charged surface, the interaction between anion and electrode is opposite to ΔE. Moreover, different arrangements of anion and cation are related to the interaction between particles. The stronger interaction leads a double-row structure and the weak interaction lead worm-like and island patterns on Au (100) surface. In general, we observed that the higher ΔE cause stronger interaction, which lead to different patterns on Au (100) surface. Meanwhile, we also confirmed that the stronger interaction between particles and electrode lead to the thinner effective EDL and a large differential capacitance value. These results provide a new perspective for double-layer structure in atomic and molecular level. This is helpful to deepen the understanding of the interface phenomena and characteristics of [Bmim]BF₄, [Bmim]PF₆, and [Bmim]TFSI on Au (100) system and provide theoretical basis for the application of these kind of systems.

Application of surfactants as anticorrosive materials: A comprehensive review

Corrosion is the degradation of a metal due to its reaction with the environment. One of the most efficient ways of securing metal surfaces from corrosion is the use of corrosion inhibitors. Their efficacy is connected to their chemical composition, their molecular structures, and their adsorption affinities on the metal surface. This review article focuses on the prospects of different types of monomeric and gemini surfactants, mixed surfactants systems, surfactants- additives mixed systems, inhibitors-surfactants (as additives) mixed systems, and ionic liquid based surfactants as promising corrosion-inhibiting formulations in the aqueous phase and the role of surfactants in developing protective coatings. The analysis starts with an accurate overview of the characteristics, types, and structure-property-performance relationship of anti-corrosion formulations of such inhibitors.

Arylamino Substituted Mercaptoimidazole Derivatives as New Corrosion Inhibitors for Carbon Steel in Acidic Media: Experimental and Computational Study

Two arylamino substituted mercaptoimidazole derivatives namely 4,5-dimethyl-1-(phenylamino)-1H-imidazole-2(3H)-thione (I1) and 4,5-dimethyl-1-((p-chlorophenyl)amino)-1H-imidazole-2(3H)-thione (I2) were synthesized and investigated as corrosion inhibitors for carbon steel in 0.5 M HCl solution by means of electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, ATR-FTIR spectroscopy and SEM. The results showed that the investigated mercaptoimidazole derivatives act as mixed type inhibitors and inhibition efficiency follows the I2>I1 order. Adsorption of inhibitors on metal surface was found to obey the Langmuir adsorption isotherm. Thermodynamic parameters revealed that adsorption of the inhibitors has both physisorption and chemisorption adsorption mechanism. Electrochemical test results were supported by quantum chemical parameters obtained from DFT calculations.

A Study of 1-Benzyl-3-phenyl-2-thiourea as an Effective Steel Corrosion Inhibitor in 1.0 M HCl Solution

1-Benzyl-3-phenyl-2-thiourea (BPTU) was studied as a steel corrosion inhibitor in 1.0 M HCl solution. Experimental methods were conducted including potentiodynamic polarization measurement (PPM), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) analysis. Quantum calculations were performed at B3LYP/6-311G(d,p). Hexamethylenetetramine (URO) was selected for comparison with BPTU. The results showed that BPTU with the concentration of 2 × 10−4 M and at the temperature of 30°C could protect the steel surface with the highest inhibition efficiency of 94.99% and 94.30% according to EIS and PPM, respectively. High temperature decreased BPTU’s ability to inhibit the steel corrosion. The adsorption of BPTU on the steel surface is followed by the modified Langmuir isotherm. Quantum chemical calculations showed that the thiourea functional group is the main adsorption center of BPTU. The experimental results are completely consistent with theoretical calculations.

Niclosamide and dichlorphenamide: new and effective corrosion inhibitors for carbon steel in 1M HCl solution

Abstract

This research demonstrates the effect of some amide compounds (1 and 2) as corrosion inhibitors on C-steel in 1.0 M of hydrochloric solutions utilizing mass reduction studies, electrochemical [potentiodynamic (PP), AC impedance measurements (EIS), electrochemical frequency modulation] techniques, and surface checks were used to illustrate the importance of amide compounds to the corrosion protection process of C-steel. The tests displayed that the inhibition efficiency (IE%) augmented with increase in amide dose but reduced with growth of temperature. The highest inhibition efficiency is 99% for compound (1) and 98.8% for compound (2) at maximum dose tested (50 µM) by polarization method. PP data show that these compounds affect both cathodic and anodic processes (i.e. mixed type) and were adsorption on the carbon steel obeying Langmuir adsorption isotherm. The EIS results indicate that the changes in impedance parameters are related to the adsorption of amides on the alloy surface. Scanning of electron microscopy, energy transmitted X-ray—Atomic force microscopy studied the morphology of inhibited C-steel.

Graphic abstract

The effect of regional selectivity on the corrosion inhibition properties of synthetic ionic liquid via the synergistic action of the cation and anion

By adding different proportions of N-butylimidazole and carboxyethylthiosuccinic acid (CETSA), three hybrid systems of ionic liquids were synthesized and named ILHS1, ILHS2 and ILHS3.

Dual-responsive carboxymethyl cellulose/dopamine/cystamine hydrogels driven by dynamic metal-ligand and redox linkages for controllable release of agrochemical

The utilization of agrochemicals in crop production is often inefficient due to lack of appropriate carriers, raising in the significant concerns of ecological environment and public health. To enhance the efficiency of agrochemical delivery, a novel cellulose-based hydrogel was constructed in this work by cross-linking dopamine (DA)-modified carboxymethyl cellulose (CMC) with cystamine (CYS) in the presence of Fe³⁺ ions. The hydrogels displayed reversible sol-gel transitions upon exposure to stimulation of changes in pH and redox, leading to the controllable release of model agrochemical (6-benzyladenine). Compared with single-triggered condition, the hydrogel doubled the cumulative release when co-triggered by pH and redox. The dynamic metal/catechol complexation and disulfide bonding coexist in the hydrogel networks, enabling occurrence of dynamic reaction under a variety of environmental conditions. The finite element method (FEM) was employed to simulate the hydrogel to provide a theoretical insight into the tested drug delivery. Benefitting from the reversibly cross-linked networks and the excellent biodegradability of the hydrogels, we anticipate that this dual-responsive, polysaccharide-based hydrogel will offer diverse applications to reach the full potential in sustainable advancement of crop production.

Influence of the adsorption of toxic agents on the optical and electronic properties of B12N12 fullerene in the presence and absence of an external electric field

The interaction energies and optoelectronic properties of sarin (SF) and chlorosarin (SC) on the B₁₂N₁₂ with and without the presence of an electric field have been studied using density functional theory (DFT) calculations.

Evaluation of corrosion inhibition performance of a novel ionic liquid based on synergism between cation and anion

A dense hydrophobic film of [Bhim]CETSA formed on the surface of A3 steel and effectively prevented contact between the steel surface and the corrosive medium.

Effect of the Structure and Temperature on Corrosion Inhibition of Thiourea Derivatives in 1.0 M HCl Solution

The corrosion inhibition ability of 1-phenyl-2-thiourea (PTU) and 1,3-diisopropyl-2-thiourea (ITU) for mild steel in 1.0 M hydrochloric was studied by using the potentiodynamic polarization (PDP) curves, electrochemical impedance spectroscopy (EIS), quantum chemical calculations, and Monte Carlo simulations. Conditions which influence the capacity of corrosion inhibition including concentration, structure of thiourea derivatives, and environment temperature were taken into investigation. The highest inhibition efficiencies of PTU and ITU are 98.96 and 92.65% at a concentration of 5 × 10^-3 M at 60 °C. In fact, corrosion inhibition ability of PTU is better than that of ITU in acidic solution due to the presence of the benzene ring of PTU. EIS data are very well correlated with PDP results. In addition, the higher inhibition performance with enhancing temperature and the values of ΔG ⁰ indicated that PTU and ITU participate in chemical adsorption on the metal surface. Their adsorption process on the metal surface follow the Langmuir adsorption isotherm. Both experimental and theoretical results in this study are in good agreement.

Guar Gum as an Eco-Friendly Corrosion Inhibitor for Pure Aluminium in 1-M HCl Solution

Guar gum (GG) was investigated as a possible eco-friendly corrosion inhibitor for pure aluminium in a 1-M HCl solution at different temperatures and immersion times using gravimetric and electrochemical techniques. The results showed that GG was a good corrosion inhibitor for pure aluminium in the studied environment. The inhibition efficiency of GG increased with increasing inhibitor concentration and immersion time but decreased with increasing temperature. Polarisation measurements revealed that GG was a mixed type inhibitor with a higher influence on the cathodic reaction. The adsorption behaviour of the investigated inhibitor was found to obey the Temkin adsorption isotherm and the calculated values of the standard free adsorption energy indicate mixed-type adsorption, with the physical adsorption being more dominant. The associated activation energy (E_a) and the heat of adsorption (Q_a) supported the physical adsorption nature of the inhibitor. Fourier-transform infrared spectroscopy (FTIR) and Raman/SERS were used to explain the adsorption interaction between the inhibitor with the surface of the metal. The results suggested that most inhibition action of GG is due to its adsorption of the metal surface via H-bond formation.

Synthesis, Cyclic Voltammetric, Electrochemical, and Gravimetric Corrosion Inhibition Investigations of Schiff Base Derived from 5,5-Dimethyl-1,3-cyclohexanedione and 2-Aminophenol on Mild Steel in 1 M HCl and 0.5 M H2SO4

Schiff base 2,2’-(5,5-dimethylcyclohexane-1,3-diylidene)bis(azan-1-yl-1-ylidene) diphenol (DmChDp) was synthesized and characterized using spectroscopic methods (IR, UV, NMR, and Mass) and cyclic voltammetric (CV) studies. The corrosion inhibition potency of (DmChDp) on mild steel (MS) in 1M HCl and 0.5M H2SO4 was investigated. The corrosion monitoring techniques employed for this purpose are gravimetric and electrochemical methods (EIS and potentiodynamic polarization studies). The study reveals that the Schiff base, DmChDp, acts as excellent corrosion inhibitor on mild steel in 1M HCl. DmChDp obeys Langmuir adsorption isotherm both in 1M HCl and 0.5M H2SO4 on MS. Polarization studies show that DmChDp behaves as a mixed type inhibitor in both media. Scanning electron microscopic analysis established the protective nature of DmChDp on mild steel surface. The impact of temperature on the corrosion of MS was also evaluated using gravimetric method.