Corrosion inhibition of mild steel in acidic medium by simple azole-based aromatic compounds

Emerging Aspects of Triazole in Organic Synthesis: Exploring its Potential as a Gelator

Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) - commonly known as the "click reaction" - serves as the most effective and highly reliable tool for facile construction of simple to complex designs at the molecular level. It relates to the formation of carbon heteroatomic systems by joining or clicking small molecular pieces together with the help of various organic reactions such as cycloaddition, conjugate addition, ring-opening, etc. Such dynamic strategy results in the generation of triazole and its derivatives from azides and alkynes with three nitrogen atoms in the five-membered aromatic azole ring that often forms gel-assembled structures having gelating properties. These scaffolds have led to prominent applications in designing advanced soft materials, 3D printing, ion sensing, drug delivery, photonics, separation, and purification. In this review, we mainly emphasize the different mechanistic aspects of triazole formation, which includes the synthesis of sugar-based and non-sugar-based triazoles, and their gel applications reported in the literature for the past ten years, as well as the upcoming scope in different branches of applied sciences.

Experimental and computational approach on the development of a new Green corrosion inhibitor formulation for N80 steel in 20% formic acid

Organic acids are employed as scale dissolvers in the oil & gas industry during production to stimulate oil recovery by pumping in the formations. Corrosion of metallic surfaces in organic acid solutions poses a significant issue in the oil and gas sector. In recent years, considering the stringent environmental regulations, there has been a growing research interest in environmentally safe inhibitors. This paper explores the synthesis of 2-(3-(carboxymethyl)-1H-imidazol-3-ium-1-yl) acetate (IZ) and its first-time application for corrosion mitigation of N80 steel in 20% formic acid. A detailed experimental study involving gravimetric, electrochemical, and surface analytical techniques is reported herein. The electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) analyses suggest a rise of impedance with IZ and a mixed-type inhibition behavior, respectively. The inhibition efficiency (IE) is 99.54% at 200 mg/L at 308 K, reaching 99.4% at 363 K with the introduction of KI as a synergistic agent. Computational studies revealed that the inhibitor IZ gets protonated in the experimental environment. The protonated form shows a tendency to receive electrons from the metal surface and shows a greater energy of adsorption compared to that of the neutral form.

Insight into the corrosion inhibiting potential and anticancer activity of 1-(4-methoxyphenyl)-5-methyl-N'-(2-oxoindolin-3-ylidene)-1H-1,2,3-triazole-4-carbohydrazide via computational approaches

Cancer is a major health concern globally. Orthodox and traditional medicine have actively been explored to manage this disease. Also, corrosion is a natural catastrophe that weakens and deteriorates metallic structures and their alloys causing major structural failures and severe economic implications. Designing and exploring multi-functional materials are beneficial since they are adaptive to different fields including engineering and pharmaceutics. In this study, we examined the anti-corrosion and anti-cancer potentials of 1-(4-methoxyphenyl)-5-methyl-N'-(2-oxoindolin-3-ylidene)-1H-1,2,3-triazole-4-carbohydrazide (MAC) using computational approaches. The molecular reactivity descriptors and charge distribution parameters of MAC were studied in gas and water at density functional theory (DFT) at B3LYP/6-311++G(d,p) theory level. The binding and mechanism of interaction between MAC and iron surface was studied using Monte Carlo (MC) and molecular dynamics (MD) simulation in hydrochloric acid medium. From the DFT, MC, and MD simulations, it was observed that MAC interacted spontaneously with iron surface essentially via van der Waal and electrostatic interactions. The near-parallel alignment of the corrosion inhibitor on iron plane facilitates its adsorption and isolation of the metal surface from the acidic solution. Further, the compound was docked in the binding pocket of anaplastic lymphoma kinase (ALK: 4FNZ) protein to assess its anti-cancer potential. The binding score, pharmacokinetics, and drug-likeness of MAC were compared with the reference drug (Crizotinib). The MAC displayed binding scores of -5.729 kcal/mol while Crizotinib has -3.904 kcal/mol. MD simulation of the complexes revealed that MAC is more stable and exhibits more favourable hydrogen bonding with the ALK receptor's active site than Crizotinib.Communicated by Ramaswamy H. Sarma.

Preparation of Bis-Thiophene Schiff Alkali-Copper Metal Complex for Metal Corrosion Inhibition

Due to the obvious numerous economic and technical consequences of the corrosion process, its inhibition is one of the most critical aspects of current research. A corrosion inhibitor for the bis-thiophene Schiff base copper-metal complex Cu(II)@Thy-2 was investigated here, which was synthesized via a coordination reaction with a bis-thiophene Schiff base (Thy-2) as a ligand and copper chloride (CuCl₂-2H₂O) as a ligand metal salt. When the corrosion inhibitor concentration was increased to 100 ppm, the self-corrosion current density I_coor reached a minimum of 2.207 × 10^-5 A/cm², the charge transfer resistance reached a maximum of 932.5 Ω·cm², and the corrosion inhibition efficiency reached a maximum of 95.2%, with the corrosion inhibition efficiency showing a trend of increasing first and then decreasing with concentration increase. After adding Cu(II)@Thy-2 corrosion inhibitor, a uniformly distributed dense corrosion inhibitor adsorption film formed on the surface of the Q235 metal substrate, significantly improving the corrosion profile compared to both before and after the addition of the corrosion inhibitor. Before and after the addition of corrosion inhibitor, the metal surface's contact angle CA increased from 54.54° to 68.37°, showing that the adsorbed corrosion inhibitor film decreased the metal surface's hydrophilicity and increased its hydrophobicity.

Falcaria vulgaris leaves extract as an eco-friendly corrosion inhibitor for mild steel in hydrochloric acid media

Undoubtedly, metal corrosion is one of the most challenging problems faced by industries. Introducing corrosion inhibitors is a reasonable approach to protecting the metal surface. Due to environmental concerns and the toxicity of industrial organic corrosion inhibitors, researchers are continually exploring acceptable replacements. The current study focused on the application of Falcaria Vulgaris (FV) leaves extract to mitigate mild steel (MS) corrosion in a 1 M HCl environment. The polarization findings demonstrated that the corrosion current density decreased from 264.0 µA/cm² (for the sample submerged in the blank solution) to 20.4 µA/cm² when the optimal concentration of 800 ppm of FV leaves extract was added to the acid solution. Electrochemical impedance spectroscopy (EIS) analysis revealed an inhibition efficiency of 91.3% at this concentration after 6 h of immersion. It was determined by analyzing several adsorption isotherms that this corrosion inhibitor obeys the Frumkin isotherm. AFM, FE-SEM, and GIXRD surface analyses also supported the findings that adding FV leaves extract can reduce metal damage by adsorption on the metal surface.

The Influence of REE β-Diketone Complexes on the Corrosion Behaviour of Mild Steel and 304 SS in 3.5% NaCl Solution

In the present investigation, four REE β-diketone complexes, namely cerium acetylacetone, cerium hexafluoroacetylacetone, lanthanum acetylacetone, and lanthanum hexafluoroacetylacetone, were investigated as potential corrosion inhibitors for mild steel and 304 stainless steel in 3.5% NaCl solution. The corrosion-inhibition effects of the REE β-diketone complexes were investigated using weight-loss measurements and potentiodynamic polarisation scans. Surface analyses using optical microscopy and scanning electron microscopy (SEM) were used to investigate the morphology of the mild steel and 304 stainless steel after the weight-loss and potentiodynamic tests in 3.5% NaCl solution containing 0.5% mass per volume (m/v) concentration of the tested inhibitor. Fourier transform infrared spectroscopy and Raman spectroscopy were further used to probe the type of corrosion product film that forms on the surface of the tested samples. The obtained results revealed that the four REE β-diketone complexes are very effective inhibitors against corrosion of mild steel and 304 stainless steel in a 3.5% NaCl in a temperature range of 20–60 °C.

Protoporphyrin Extracted from Biomass Waste as Sustainable Corrosion Inhibitors of T22 Carbon Steel in Acidic Environments

Carbon steel is one of the most employed materials in many industrial sectors due to its unique physical and mechanical properties. However, within a certain period of time, carbon steel-based materials are susceptible to corrosion under operating conditions and corrosion inhibitors are important to extending the limit of use of carbon steel. In this study, the influence of protoporphyrin from animal blood hemin as an eco-friendly corrosion inhibitor for T22 carbon steel in an acidic environment (0.5 M HCl) was conducted. The hemin isolated from animal blood extracts was modified to obtain the protoporphyrin. The dosage of protoporphyrin was varied between 40 and 200 ppm and the temperature influence were studied in the range of 298–318 K. The inhibition efficiency of protoporphyrin in 0.5 M hydrochloric acid reached up to 46.2% at a dose of 160 ppm at a temperature of 298 K. The inhibition efficiency (IE) value further decreases with increasing temperature, thereby showing the process exothermic in nature and the weakening of the inhibitor molecules to adsorb on the surface of the T22 carbon steel. The potentiodynamic polarization measurements indicate that protoporphyrin acts as a mixed-type inhibitor. The adsorption of protoporphyrin on the surface of T22 carbon steel obeys the Langmuir adsorption isotherm. The thermodynamic parameter of adsorption allows us to suggest the adsorption process was dominated by physical adsorption. Thus, these current results present a case study using protoporphyrin as a promising green inhibitor for carbon steel T22 in hydrochloric acid prepared from livestock waste.

Additively manufactured high-performance polymeric materials and their potential use in the oil and gas industry

The oil and gas industry has been tagged as among the largest revenue-generating sectors in the world. High-performance polymers (HPPs), on the other hand, are among the most useful industrial materials, while the utility of 3D printing technologies has evolved and transitioned from rapid prototyping of composite materials to manufacturing of functional parts. In this prospective, we highlight the potential uses and industrial applications of 3D-printed HPP materials in the oil and gas sector, including the challenges and opportunities present.

GRAPHICAL ABSTRACT

Electropolymerized-molecularly imprinted polymers (E-MIPS) as sensing elements for the detection of dengue infection

A straightforward in situ detection method for dengue infection was demonstrated through the molecular imprinting of a dengue nonstructural protein 1 (NS1) epitope into an electropolymerized molecularly imprinted polyterthiophene (E-MIP) film sensor. The key enabling step in the sensor fabrication is based on an epitope imprinting strategy, in which short peptide sequences derived from the original target molecules were employed as the main template for detection and analysis. The formation of the E-MIP sensor films was facilitated using cyclic voltammetry (CV) and monitored in situ by electrochemical quartz crystal microbalance (EC-QCM). Surface properties were analyzed using different techniques including atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and polarization modulation-infrared reflection-adsorption (PM-IRRAS). The standard calibration curve (R = 0.9830) was generated for the detection of the epitope, Ac-VHTWTEQYKFQ-NH₂, with a linear range of 0.2 to 30 μg/mL and detection limit of 0.073 μg/mL. A separate calibration curve (R = 0.9786) was obtained using spiked buffered solutions of dengue NS1 protein, which resulted in a linear range of 0.2 to 10 μg/mL and a detection limit of 0.056 μg/mL. The fabricated E-MIP sensor exhibited long-term stability, high sensitivity, and good selectivity towards the targeted molecules. These results indicated that the formation of the exact and stable cavity imprints in terms of size, shape, and functionalities was successful. In our future work, we aim to use our E-MIP sensors for NS1 detection in real-life samples such as serum and blood.