An efficient green ionic liquid for the corrosion inhibition of reinforcement steel in neutral and alkaline highly saline simulated concrete pore solutions

The effect of the green ionic liquid compound, Quaternium-32 (Q-32), on the corrosion inhibition performance of reinforcement steel, in a simulated concrete pore solution, was investigated at different temperatures and pH values, using electrochemical impedance spectroscopy (EIS). The inhibition efficiency was improved as the concentration of Q-32 and pH values were increased. However, it decreased as the temperature was raised. A Q-32 concentration of 20 µmol L–1 exhibited a 94% inhibition efficiency at 20 °C. The adsorption isotherm was evaluated using EIS measurements, and it was found to obey the Langmuir isotherm. The surface topography was examined using an atomic force microscope and scanning electron microscope. The effect of the Q-32 concentration with the highest corrosion efficiency on the mechanical properties of the mortars was also explained by flexure and compression techniques.The authors express their gratitude to the Center for Advanced Materials at Qatar University for technical support. Additionally, the authors are grateful to Qatar University for funding this work through the QUCG-CAM-20/21-2 Grant. The publication of this article was funded by the Qatar National Library

Organ-specific toxicity evaluation of stearamidopropyl dimethylamine (SAPDMA) surfactant using zebrafish embryos

Surfactants are widely used in the industry of detergents, household products, and cosmetics. SAPDMA is a cationic surfactant that is used mostly in cosmetics, conditioning agents and has recently gained attention as a corrosion inhibitor in the sea pipelines industry. In this regard, literature concerning the ecotoxicological classification of SAPDMA on aquatic animals is lacking. This study aims to evaluate the potential ecotoxicity of SAPDMA using the aquatic zebrafish embryo model. The potential toxic effects of SAPDMA were assessed by different assays. This includes (i) mortality/survival assay to assess the median lethal concentration (LC50); (ii) teratogenicity assay to assess the no observed effect concentration (NOEC); (iii) organ-specific toxicity assays including cardiotoxicity, neurotoxicity (using locomotion assay), hematopoietic toxicity (hemoglobin synthesis using o-dianisidine staining), hepatotoxicity (liver steatosis and yolk retention using Oil Red O (ORO) stain); (iv) cellular cytotoxicity (mitochondrial membrane potential) by measuring the accumulation of JC-1 dye into mitochondria. Exposure of embryos to SAPDMA caused mortality in a dose-dependent manner with a calculated LC50 of 2.3 mg/L. Thus, based on the LC50 value and according to the Fish and Wildlife Service (FWS) Acute Toxicity Rating Scale, SAPDMA is classified as “moderately toxic”. The No Observed Effect Concentration (NOEC) concerning a set of parameters including scoliosis, changes in body length, yolk, and eye sizes was 0.1 mg/L. At the same NOEC concentration (0.1 mg/L), no organ-specific toxicity was detected in fish treated with SAPDMA, except hepatomegaly with no associated liver dysfunctions. However, higher SAPDMA concentrations (0.8 mg/L) have dramatic effects on zebrafish organ development (eye, heart, and liver development). Our data recommend a re-evaluation of the SAPDMA employment in the industry setting and its strictly monitoring by environmental and public health agencies

Electrochemical and thermodynamic study on the corrosion performance of API X120 steel in 3.5% NaCl solution

The present work studied the effect of temperature on the corrosion behavior of API X120 steel in a saline solution saturated with CO2 in absence and presence of polyethyleneimine (PEI) as an environmentally safe green inhibitor. The effect of PEI on the corrosion behavior of API X120 steel was investigated using destructive and non-destructive electrochemical techniques. The overall results revealed that PEI significantly decreases the corrosion rate of API X120 steel with inhibition efficiency of 94% at a concentration of 100 μmol L−1. The adsorption isotherm, activation energy and the thermodynamic parameters were deduced from the electrochemical results. It is revealed that the adsorption of PEI on API X120 steel surface follows Langmuir adsorption isotherm adopting a Physi-chemisorption mechanism. Finally, the samples were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques to elucidate the effect of aggressiveness of corrosive media on the surface morphology and the corrosion performance of API X120 steel. The surface topography result indicates that the API X120 steel interface in PEI presence is smoother than CO2 with Cl− ions or Cl− ions only. This is attributed to the compact protective film limits the aggressive ions transfer towards the metallic surface and reduces the corrosion rate. Moreover, PEI inhibition mechanism is based on its CO2 capturing ability and the PEI adsorption on the steel surface beside the siderite layer which give the PEI molecules the ability to reduce the scale formation and increase the corrosion protection due to capturing the CO2 from the brine solution

Enhanced mechanical and corrosion protection properties of pulse electrodeposited NiP-ZrO2 nanocomposite coatings

Pulse electrodeposition is a technique of particular interest, which offers promising advantages such as ease of processing, compositional control, uniformity in structure, and grain refinement. In the present study, NiP-ZrO2 nanocomposite coatings containing various concentrations of ZrO2 nanoparticles (ZONPs) were deposited on low alloy steel (30CrMnSi) through pulse electrodeposition technique. The ZONPs in concentration of 0.0, 0.25, 0.50, 0.75, and 1.0 g/L were added in the electrolyte bath to obtain NiP-ZrO2 nanocomposite coatings. Furthermore, to elucidate the role of ZONPs in the NiP matrix, the structural, morphological, mechanical, and electrochemical properties of NiP-ZrO2 nanocomposite coatings were studied thoroughly. FESEM and EDX results reveal the successful incorporation of ZONPs into the NiP matrix. XRD and XPS analysis confirm the formation of a pure phase NiP structure without any noticeable defects. A considerable improvement in the mechanical response was observed with an increasing amount of ZONPs, reaching to highest values (hardness 6.7 GPa, modulus of elasticity 21.72 GPa) for NiP-1.0 ZrO2 coating composition. Similarly, the electrochemical results show a gradual increase in corrosion protection behavior of the NiP-ZrO2 coatings with increasing ZONP concentration, reaching an eventual value ~5.8 kΩ cm−2 at NiP-1.0 ZrO2 coating composition, which is six times greater than the pure NiP coatings. These improvements in the mechanical and electrochemical response of NiP-ZrO2 nanocomposite coatings highlight their suitability for applications such as oil and gas pipelines

Eco-Friendly Synthesis, Biological Evaluation, and In Silico Molecular Docking Approach of Some New Quinoline Derivatives as Potential Antioxidant and Antibacterial Agents

A new series of quinoline derivatives 5–12 were efficiently synthesized via one-pot multicomponent reaction (MCR) of resorcinol, aromatic aldehydes, β-ketoesters, and aliphatic/aromatic amines under solvent-free conditions. All products were obtained in excellent yields, pure at low-cost processing, and short time. The structures of all compounds were characterized by means of spectral and elemental analyses. In addition, all the synthesized compounds 5–12 were in vitro screened for their antioxidant and antibacterial activity. Moreover, in silico molecular docking studies of the new quinoline derivatives with the target enzymes, human NAD (P)H dehydrogenase (quinone 1) and DNA gyrase, were achieved to endorse their binding affinities and to understand ligand–enzyme possible intermolecular interactions. Compound 9 displayed promising antioxidant and antibacterial activity, as well as it was found to have the highest negative binding energy of -9.1 and -9.3 kcal/mol for human NAD (P)H dehydrogenase (quinone 1) and DNA gyrase, respectively. Further, it complied with the Lipinski’s rule of five, Veber, and Ghose. Therefore, the quinoline analogue 9 could be promising chemical scaffold for the development of future drug candidates as antioxidant and antibacterial agents

Electrospun highly corrosion-resistant polystyrene–nickel oxide superhydrophobic nanocomposite coating

A key challenge in producing superhydrophobic coatings (SHC) is to tailor the surface morphology on the micro-nanometer scale. In this work, a feasible and straightforward route was employed to manufacture polystyrene/nickel oxide (PSN) nanocomposite superhydrophobic coatings on aluminum alloys to mitigate their corrosion in a saline environment. Different techniques were employed to explore the influence of the addition of NiO nanoparticles to the as-prepared coatings. PSN-2 composite with ~ 4.3 wt% of NiO exhibited the highest water contact angle (WCA) of 155° ± 2 and contact angle hysteresis (CAH) of 5°. Graphic abstract: EIS Nyquist plots of 3 g of electrospun polystyrene coatings (a) without and with (b) 0.1, (c) 0.15, and (d) 0.2 g of NiO. [Figure not available: see fulltext.

Theoretical and experimental insights into the C-steel aqueous corrosion inhibition at elevated temperatures in 1.0M HCl via multi-carbonyl Gemini cationic surfactants

Despite corrosion being an inevitable process, researchers strive to control corrosion. In this study, our goal was to prepare two amido Gemini cationic surfactants, LAPG and MAPG, each with different alkyl chains and multiple carbonyl groups as rich electronic rich centers. We aimed to evaluate these surfactants as potential corrosion inhibitors for carbon steel (CS) in 1M HCl at temperatures of 25-55 ± 0.1°C. In theoretical investigations, DFT parameters and Mont Carlo simulation were run to predict the adsorption affinity and reactive sites of the LAPG and MAPG molecules. Their efficacy was investigated experimentally considering weight loss and electrochemical techniques. The Tafel polarization revealed that at 0.1mM of LAPG and MAPG, the corrosion current density (i corr) of CS was reduced to the lowest extent (75.56 and 53.82μAcm-2) compared to 529.3μAcm-2 in the absence of the inhibitors. EIS data suggests the enhancement of the thickness of the adsorbed layers of the studied compounds from the decrease of the double-layer capacitance C dl values. The Langmuir isotherm explained the adoption phenomena of these compounds at 25-55 ± 0.1°C. Activation and adsorption thermodynamic parameters predicted the chemisorption behavior of these molecules onto the steel surface. AFM and XPS tools confirm the CS surface protection due to these inhibitors' adsorbed layer. A parallel study showed the superiority of these corrosion inhibitors in HCl compared with those reported earlier, making these compounds highly promising corrosion inhibitors, especially in high-temperature acidic environments

Synthesis of Gemini cationic surfactants based on natural nicotinic acid and evaluation of their inhibition performance at C-steel/1 M HCl interface: Electrochemical and computational investigations

Herein, we prepare effective Gemini cationic surfactants (CSII, CSIV) and characterize them using FT-IR and 1HNMR spectroscopy. The adsorptive properties of CSII and CSIV at HCl/air and C-steel/HCl interfaces were examined with surface tension and electrochemical parameters, respectively. The critical micelle concentration (CMC) of the CSII and CSIV indicated their adsorption affinity at the HCl/air interface. Where, aliphatic chains increase surface coverage percentage and aid in surfactant adsorption. The electrochemical parameters of C-steel in 1 M HCl were studied using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) at different temperatures. The charge transfer resistance of the C-steel electrode was enhanced from 28.2 Ω.cm2 to 770.79 and 831.45 Ω.cm2 after adding 5 × 10−4 M of CSII and CSIV, respectively. Both CSII and CSIV act as mixed inhibitors with inhibition performance exceeding 97% due to their highly adsorption affinity. The chemical adsorption affinity of these compounds is suggested by the higher adsorption energy (∆G*ads) values (>−40 kJ mol−1) according to the Langmuir isotherm model. The theoretical calculations including DFT, and Monte Carlo simulation (MCs) provide insight into the relationship between corrosion inhibition and molecular structure, where the calculated parameters agree with the experimental results

AEO-7 surfactant is “super toxic” and induces severe cardiac, liver and locomotion damage in zebrafish embryos

© 2020, The Author(s). Background: Fatty alcohol polyoxyethylene ether-7 (AEO-7), a non-ionic surfactant, has recently been receiving extensive attention from the ocean pipeline industry for its ability to inhibit corrosion. However, the present lack of information concerning the potential environmental toxicity of AEO-7, especially towards aquatic organisms, is a major impediment to its wider application. Here, we assess potential adverse effects of AEO-7 on zebrafish embryos employing a variety of assays, including (i) a mortality/survival assay which allowed the median lethal concentration (LC50) to be calculated; (ii) a teratogenicity assay on the basis of which the no observed effect concentration (NOEC) was determined; and (iii) specific assays of cardiotoxicity, neurotoxicity (based on locomotion), hematopoietic toxicity (the level of hemoglobin as revealed by o-dianisidine staining) and hepatotoxicity (liver steatosis and yolk retention examined by staining with Oil Red O). Results: AEO-7 caused mortality with a calculated LC50 of 15.35 μg/L, which, according to the U.S. Fish and Wildlife Service (USFWS) Acute Toxicity Rating scale, should be considered “super toxic”. Although at its NOEC (0.8 μg/L), there were no signs of significant teratogenicity, cardiotoxicity, or hemopoiesis toxicity, 3.2 µg/L AEO-7 exerted dramatic detrimental effects on organ development. Conclusion: On the basis of these findings, we recommend that the industrial usage and environmental impact of AEO-7 be re-evaluated and strictly monitored by environmental and public health organizations

Capsaicin ameliorate pulmonary fibrosis via antioxidant Nrf-2/ PPAR- γ pathway activation and inflammatory TGF-β1/ NF-κB/COX II pathway inhibition

Bleomycin is an effective antibiotic with a significant anticancer properties, but its use is limited due to its potential to induce dose-dependent pulmonary fibrosis. Therefore, this study aimed to assess the therapeutic potential of Capsaicin as an additional treatment to enhance patient tolerance to Bleomycin compared to the antifibrotic drug Pirfenidone. Pulmonary fibrosis was induced in rats through by a single intratracheal Bleomycin administration in day zero, followed by either Capsaicin or Pirfenidone treatment for 7 days. After the animals were sacrificed, their lungs were dissected and examined using various stains for macroscopic and histopathological evaluation. Additionally, the study assessed various antioxidant, anti-inflammatory, and antifibrotic parameters were assessed. Rats exposed to Bleomycin exhibited visible signs of fibrosis, histopathological alterations, increased collagen deposition, and elevated mucin content. Bleomycin also led to heightened increased inflammatory cells infiltration in the bronchoalveolar lavage, elevated fibrosis biomarkers such as hydroxyproline, alpha-smooth muscle actin (α-SMA) and transforming growth factor-beta (TGF-β1), increased inflammatory markers including tumor necrosis factor-alpha (TNF-α), interlukine-6 (Il-6), interlukine-1β (Il-1β) nuclear factor-kappa B (NF-κB), and Cyclooxygenase-2 (COX-2), and transforming growth factor-beta (TGF-β1),. Furthermore, it reduced the expression of peroxisome proliferator-activated receptor-gamma (PPAR-γ), increased oxidative stress biomarkers like nitric oxide (NO), malondialdehyde (MDA), myeloperoxidase (MPO) and protein carbonyl. Bleomycin also decreased the expression of nuclear factor erythroid 2–related factor 2 (Nrf-2), reduced glutathione (GSH), total antioxidant capacity, and the activities of catalase and superoxide dismutase (SOD). Treating the animals with Capsaicin and Pirfenidone following Bleomycin exposure resulted in improved lung macroscopic and microscopic characteristics, reduced collagen deposition (collagen I and collagen III) and mucin content, decreased inflammatory cell infiltration, lowered levels of hydroxyproline, α-SMA, and TGF-β1, decreased TNF-α, Il-6, Il-1β, NF-κB, and COX-2, increased PPAR-γ and Nrf-2 expression, and improvement improved in all oxidative stress biomarkers. In summary, Capsaicin demonstrates significant antifibrotic activity against Bleomycin-induced lung injury that may be attributed, at least in part, to the antioxidant and anti-inflammatory activities of Capsaicin mediated by upregulation of PPAR-γ and Nrf-2 expression and decreasing. TGF-β1, NF-κB and COX II proteins concentrations