Effect of 1-(3-phenoxypropyl) pyridazin-1-ium bromide on steel corrosion inhibition in acidic medium

Corrosion inhibition study of 6061 aluminium alloy in the presence of ethyl 5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazole-4-carboxylate (NTE) in hydrochloric acid

The inhibitory effect of an ethyl 5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazole-4-carboxylate (NTE) was investigated on the corrosion of Al (AA6061) alloy at different temperatures (303-333 K) by Electrochemical impedance spectroscopy (EIS), Potentiodynamic polarization (PDP), and weight loss techniques. It was found that NTE molecules protect the aluminium against corrosion and its ability increases with increasing concentrations, and temperature resulting in better inhibitory performance. At all concentrations and temperature ranges, NTE exhibited mixed inhibitor action and complied with the Langmuir isotherm. At 100 ppm and 333 K, NTE demonstrated the highest inhibition efficiency (94%). The EIS results and the PDP results had a good level of concordance. A suitable mechanism for the corrosion prevention of AA6061 alloy was proposed. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to confirm the adsorption of an inhibitor onto the aluminium alloy surface. The electrochemical results were validated by morphological examination, which demonstrated that NTE prevents uniform corrosion of aluminium alloy in acid chloride solutions. The activation energy and thermodynamic parameters were computed, and the results were discussed.

Efficient Antibacterial Dimeric Nitro Imidazolium Type of Ionic Liquids from a Simple Synthetic Approach

Synthesis of dimeric nitro-substituted imidazolium salts under the conventional/solvent-free method is reported. The solvent-free method is more important than the conventional one because of its shorter reaction time, higher yield from easily available starting material, environmental safety, and so forth. Counter anion exchange is carried out using inorganic salt, which is dissolved in deionized water at room temperature. In antibacterial studies, dimeric nitro-substituted imidazolium cations with bromide counter anions showed excellent inhibition against E. coli and P. aeruginosa bacteria. These experimental results were further supported by molecular docking studies. All the compounds (3-6) (a-d) showed excellent antibacterial activity than the standard drugs (gentamycin, nalidixic acid, oflaxacin, ciproflaxacin, and amikacin). Molecular docking studies showed strong hydrogen bonding, polar and hydrophobic interactions between the dimeric imidazolium salts, and Escherichia coli/Pseudomonas aeruginosa/Proteus vulgaris/Staphylococcus aureus receptors.

Locust Bean Gum: Processing, Properties and Food Applications

Locust bean gum is derived from the seed endosperm of the Ceratonia siliqua carob tree and is known as locust bean or carob gum. Food, medicines, paper, textile, oil drilling, and cosmetic sectors all use it as an ingredient. Hydrogen bonding with water molecules makes locust bean gum useful in industrial settings. In addition, its dietary fibre activity helps regulate numerous health issues, including diabetes, bowel motions, heart disease and colon cancer. Locust bean gum production, processing, composition, characteristics, culinary applications, and health advantages are the subject of this article.

In Silico Approaches for Some Sulfa Drugs as Eco-Friendly Corrosion Inhibitors of Iron in Aqueous Medium

This paper addresses the prediction of the adsorption behavior as well as the inhibition capacity of non-toxic sulfonamide-based molecules, also called sulfa drugs, on the surface of mild steel. The study of the electronic structure was investigated through quantum chemical calculations using the density functional theory method (DFT) and the direct interaction of inhibitors with the iron (Fe) metal surface was predicted using the multiple probability Monte Carlo simulations (MC). Then, the examination of the solubility and the environmental toxicity was confirmed using a chemical database modeling environment website. It was shown that the presence of substituents containing heteroatoms able to release electrons consequently increased the electron density in the lowest unoccupied and highest occupied molecular orbitals (LUMO and HOMO), which allowed a good interaction between the inhibitors and the steel surface. The high values of EHOMO imply an ability to donate electrons while the low values of ELUMO are related to the ability to accept electrons thus allowing good adsorption of the inhibitor molecules on the steel surface. Molecular dynamics simulations revealed that all sulfonamide molecules adsorb flat on the metal surface conforming to the highly protective Fe (1 1 0) surface. The results obtained from the quantum chemistry and molecular dynamics studies are consistent and reveal that the order of effectiveness of the sulfonamide compounds is P7 > P5 > P6 > P1 > P2 > P3 > P4.

Organic Compounds as Corrosion Inhibitors for Carbon Steel in HCl Solution: A Comprehensive Review

Most studies on the corrosion inhibition performance of organic molecules and (nano)materials were conducted within “carbon steel/1.0 M HCl” solution system using similar experimental and theoretical methods. As such, the numerous research findings in this system are sufficient to conduct comparative studies to select the best-suited inhibitor type that generally refers to a type of inhibitor with low concentration/high inhibition efficiency, nontoxic properties, and a simple and cost-economic synthesis process. Before data collection, to help readers have a clear understanding of some crucial elements for the evaluation of corrosion inhibition performance, we introduced the mainstay of corrosion inhibitors studies involved, including the corrosion and inhibition mechanism of carbon steel/HCl solution systems, evaluation methods of corrosion inhibition efficiency, adsorption isotherm models, adsorption thermodynamic parameters QC calculations, MD/MC simulations, and the main characterization techniques used. In the classification and statistical analysis section, organic compounds or (nano)materials as corrosion inhibitors were classified into six types according to their molecular structural characteristics, molecular size, and compound source, including drug molecules, ionic liquids, surfactants, plant extracts, polymers, and polymeric nanoparticles. We outlined the important conclusions obtained from recent literature and listed the evaluation methods, characterization techniques, and contrastable experimental data of these types of inhibitors when used for carbon steel corrosion in 1.0 M HCl solution. Finally, statistical analysis was only performed based on these data from carbon steel/1.0 M HCl solution system, from which some conclusions can contribute to reducing the workload of the acquisition of useful information and provide some reference directions for the development of new corrosion inhibitors.

Insight into the anti-corrosion performance of two food flavors as eco-friendly and ultra-high performance inhibitors for copper in sulfuric acid medium

2,5-dihydroxy-1,4-dithiane (DDD) and 2,5-dimethy- [1.4] dithiane-2,5-diol (DTDD) two food flavors as environmentally-friendly inhibitors for Cu in 0.5 mol/L H₂SO₄ media were researched via theoretical calculation and experimental ways. Electrochemical measurement data showed that DDD and DTDD can exhibit high level anti-corrosion feature. The anti-corrosion efficiency of DDD and DTDD were as high as 99.6% and 98.9%, respectively. The atomic force microscope (AFM) and scanning electron microscope (SEM) tests showed that the Cu specimens were immersed in the H₂SO₄ with 5 mM DDD and DTDD for 30 h at the 298 K, and the Cu specimen surface was still smooth. Besides, the adsorption of DDD and DTDD at the interface of Cu/solution was comply with Langmuir adsorption. Theoretical calculation data showed that DDD exhibit more ascendant anti-corrosion feature than DTDD.

Novel triazole derivatives as ecological corrosion inhibitors for mild steel in 1.0 M HCl: experimental & theoretical approach

The present paper illustrates the investigation of two novel ecological triazole derivative corrosion inhibitors, namely ethyl 2-(4-phenyl-1H-1,2,3-triazol-1-yl) acetate [Tria-CO₂Et], and 2-(4-phenyl-1H-1,2,3-triazol-1-yl) acetohydrazide [Tria-CONHNH₂].

Insight into anti-corrosion nature of Betel leaves water extracts as the novel and eco-friendly inhibitors

In this paper, the simple and low-cost water extraction way was used to acquisition Betel leaves extracts (BLE). The water as the extraction solvent has the characteristics of low price, environmentally friendly, and good solubility for other extraction solvents. BLE was researched as an environmental-friendly inhibitor via various experimental methods and theoretical calculations. Electrochemical experiments manifest that BLE can restrain reactions of the cathode and anode of Q235 steel. The BLE concentration was 400 mg/L, the anti-corrosion efficiency was close to 94%. The experimental data show that BLE can show high-quality anti-corrosion nature for Q235 steel immersing in 1 M hydrochloric acid (HCl) environment at a certain temperature range. The morphology maps of scanning electron microscope (SEM) and atomic force microscopy (AFM) strongly proves the data of electrochemical experiments. In addition, the BLE adsorption at the Q235 steel surface belongs to the Langmuir mono-layer adsorption. Quantum chemical calculations (QCC) and molecular dynamics simulations (MDS) effectually manifest that BLE can show decent anti corrosion character.

Construction of a sustainable/controlled-release nano-container of non-toxic corrosion inhibitors for the water-based siliconized film: Estimating the host-guest interactions/desorption of inclusion complexes of cerium acetylacetonate (CeA) with beta-cyclodextrin (β-CD) via detailed electronic/atomic-scale computer modeling and experimental methods

Utilization of the coatings with self-healing anti-corrosion activities is one of the most promising routes for the development of advanced anti-corrosion coatings. In the present work, the green/sustainable corrosion inhibitive compounds based on the cerium acetylacetonate (CeA) was loaded into a beta-cyclodextrin (β-CD) nano-container (with negligible hazardous impacts) and through combined computer modeling and experimental approaches, the host-guest interactions/desorptions of the inclusion complexes of CeA with beta-cyclodextrin (β-CD) were assessed. The inhibition performance of the β-CD-CeA inclusion complex was investigated by electrochemical and surface experiments in a saline solution (NaCl, 3.5 wt.%). The particles were analyzed by Raman, XRD, FT-IR, and UV-vis spectroscopies. Additionally, the thermal properties in the 30-600 °C temperature range were examined by employing TGA/DTG test, and via the ICP analysis, the concentration of the released inorganic compounds in the electrolyte was studied. Achievements demonstrated 24 ppm Ce element existence after introducing β-CD-CeA inclusion complexes (during 24 h) in NaCl 3.5 wt.% solution. The analysis of Tafel curves proved that the prepared β-CD-CeA inclusion complex could inhibit the metallic substrate corrosion following the mixed cathodic and anodic mechanisms. The EIS investigation disclosed about 82 % inhibition degree after 48 h of metal immersion in the solution containing β-CD-CeA extract. The EIS analysis clarified that the silane coating (SC) resistance was enhanced noticeably by introducing the β-CD-CeA particles into the SC matrix. Using detailed-level (i.e., electronic and atomic) computer modeling techniques applying density functional theory (DFT), Mote Carlo (MC) and molecular dynamics (MD), the active sites, and the adsorption propensity of CeA complexes over the steel-based metallic adsorbents were explored. These modelings evidenced the CeA complexes interfacial adsorption on the steel.

The sandwich-like structures of polydopamine and 8-hydroxyquinoline coated graphene oxide for excellent corrosion resistance of epoxy coatings

A novel sandwich-like structure material was exploited for the fabrication of an effective corrosion resistance system. An environmentally friendly composite material was synthesized by installing 8-hydroxyquinoline (8-HQ) on the surface of graphene oxide (GO). In order to prevent leakage of corrosion inhibitor 8-HQ, GO/8-HQ was modified by polydopamine (PDA), denoted as GO/8-HQ/PDA. A sandwich-like structure (GO/8-HQ/PDA) enables long-term stable storage of corrosion inhibitor in the protective matrix. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were utilized to verify the sandwich-like structure of GO/8-HQ/PDA. The electrochemical tests in a 3.5 wt% NaCl solution showed that the addition of well-dispersed GO/8-HQ/PDA into epoxy system (GO/8-HQ/PDA-EP) remarkably improved corrosion protection of AZ31b magnesium alloy compared with pure epoxy (EP) coating. The sandwich structure protects the activity and structural integrity of the corrosion inhibitor (8-HQ). The corrosion inhibitor (8-HQ) of the GO/8-HQ/PDA sandwich structure cuts off the ion exchange between the metal alloy and the electrolyte solution, which hinders the electrochemical corrosion of the metal. A possible corrosion resistance mechanism of GO/8-HQ/PDA is fully discussed. This study provides feasibilities for the immobilization of corrosion inhibitors on the metal surface.