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• Two novel poly Schiff bases were prepared as corrosion inhibitors in sour media. • The PSB2 inhibited sour corrosion more effectively than PSB1 inhibitors. • At 328 oK the inhibition efficiencies for the two polymers were 61.85% and 67.4%. • The PSB2′s high activation energy showed a reduction in the steel's corrosion rate. • The developed polymers prompt the upcoming strategy for corrosion-inhibitors. In this work, two novel Schiff base polymers (PSB1 and PSB2) with extra-high protective barrier features were facilely prepared via polycondensation reactions. They were applied for the first time as effective corrosion inhibitors in the sour corrosive media of petroleum environments containing hydrogen sulfide (H 2 S) gas. For studying the polymers' inhibitive action on the carbon steel, numerous corrosion testing methods including potentiodynamic polarization (PDP), open circuit potential, and electrochemical impedance spectroscopy (EIS) have been employed at various temperatures (298–328 K) in the oil wells formation water with H 2 S concentrations of 100, 400, and 700 ppm as aggressive media. The activation energy (E a) and other thermodynamic parameters were computed to describe the mechanism of adsorption. The corrosion morphological traits and steel samples' surfaces composition were analyzed by field emission scanning electron microscope and energy dispersive X-ray analyses. The quantum calculations were used to investigate electronic structures and molecular geometry which revealed the polymers' kinetic stability and chemical reactivity. The PSB2 inhibited sour corrosion more effectively than PSB1 when subjected to electrochemical testing. The 100 ppm concentration of PSB2 exhibited 82.18% and 81.14% inhibition efficiencies at 298 K in PDP and EIS measurements, respectively. While at 328 K, the inhibition efficiencies were 61.85% and 67.4% at the same dosage and measurements. These poly Schiff bases exhibited fascinating performance as corrosion inhibitors in sour environment. They provide a great corrosion inhibition platform for the sustainable future environment. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Novel core–shell preparing poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) and copolymers with acrylic acid (AA) or acrylamide (AM) magnetic nanogels with controllable particle size produced via free aqueous polymerization at room temperature have been developed for the first time. The crosslinking polymerization was carried out in the presence of N,N′-methylenebisacrylamide (MBA) as a crosslinker, N,N,N′,N′-tetramethylethylenediamine (TEMED) and potassium peroxydisulfate (KPS) as redox initiator system. The structure and morphology of the magnetic nanogels were characterized by Fourier transform infrared spectroscopy (FTIR), transmission and scanning electron microscopy (TEM and SEM). The effectiveness of the synthesized compounds as corrosion inhibitors for carbon steel in 1M HCl was investigated by various electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed enhancement in inhibition efficiencies with increasing the inhibitor concentrations and temperatures. The results showed the nanogel particles act as mixed inhibitors. Adsorption of nanogel particles was found to fit the Langmuir isotherm and was chemisorption. [Copyright &y& Elsevier]

Superparamagnetic magnetite-alginate nanoparticles (M-AlgNPs) were synthesized utilizing a coprecipitation method. Then, the prepared M-AlgNPs were characterized via Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction spectroscopy (XRD) to affirm the formation and the crystallinity of this composite. In addition, the surface morphology of the prepared nanoparticles was inspected by transmission electron microscopy (TEM) which revealed well-dispersed nanoparticles of Fe3O4 into alginate. The adsorption characteristics of the synthesized nanoparticles for removing Ni+2 and Co+2 from wastewater were evaluated via atomic absorption measurements (AAS). The elimination efficiency of the M-AlgNPs was detected at pH=7 in 100 ppm (initial concentration) of Ni+2 and Co+2, separately. The M-AlgNPs provided the maximum equilibrium uptake percentage for Ni+2 and Co+2 of 97.88 and 95.01%, respectively. The adsorption of Ni+2 and Co+2 onto the M-AlgNP surface was found to fit the Langmuir model with R2 values higher than that obtained from the Freundlich model for both metal ions. Moreover, RL "separating factor" for the adsorption process was assessed and found to be less than unity; this expresses the higher ability of the investigated metal ions to be adsorbed onto the M-AlgNP surface. The adsorption method was discovered to be pH-dependent and well-suited to the isothermal equations of Langmuir and Freundlich. For regeneration studies, M-AlgNPs have been investigated and results confirmed that it could be reused with effective sorption capacity over three cycles. [ABSTRACT FROM AUTHOR]

The studied Schiff-base compounds in this work are multitasked investigated as corrosion inhibitors and also, to improve the physical and mechanical properties of reinforced concrete. The efficiency inhibition of the two novel Schiff-base compounds named (DHSiMF) and (DHSiB) for corrosion of carbon-steel in aqueous media of 1 M HCl was assessed via electrochemical methods and loss in weight. FT-IR, 1H-NMR spectra and elemental analysis were used to confirm the structure of such compounds. It was found to have successful inhibition even at low concentrations in tested media, as an increase in inhibitor concentration led to an improvement in the inhibition efficiency. The weight loss results clearly demonstrate that DHSiMF of C-steel in 1 M HCl has a higher inhibition efficiency than DHSiB, with a maximum inhibition efficiency (85%) attained at 1 × 10–2 M from DHSiMF. Electrochemical experiments likewise revealed the same order, but with a maximal inhibitory efficiency of 98.1%. The addition of inhibitors to the corrosive media dramatically changed the anodic Tafel constants (βa) and cathodic Tafel constants (βc), indicating a mixed type nature. Electrochemical polarization curves illustrated the functions of mixed-type inhibition and the action of adsorption matching with the Langmuir adsorption isotherm. The ∆Gads values for DHSiMF and DHSiB at temperatures (ranging from 303 to 333 K) are − 34.42 kilojoule/mole to − 37.51 kilojoule/mole. These values indicate that the compounds' adsorption types are chemo-physical adsorption. X-ray diffraction (XRD) and Scanning electron microscopy (SEM) experiments were used to check the existence of the protection layer on the surface of carbon steel by analyzing the morphologies of the corrosion effects and the formed chemical compositions of the corrosion outcomes. For the concrete, the findings suggest that the chemical reaction that takes place between the DHSiMF and DHSiB and the concrete mix will result in an increase in the flexural strength, the compressive strength, and the indirect tensile strength of the concrete that is made of the gravel and dolomite aggregate. [ABSTRACT FROM AUTHOR]

The great demand on the energy makes the attention toward modifying lubricating oil. This work tends to prepare the following copolymers; octadecylmethacrylate-co-dodecene (CP1) and octadecylmethacrylate-co-hexadecene (CP2) by free radical solution polymerization using laboratory prepared octadecylmethacrylate monomer with either 1-dodecene or 1-hexadecene. The same monomers also used to prepare their polymers nanocomposite (NP1, NP2) with 1% of nanomontmorolonite by emulsion polymerization. The structures of the prepared polymers and their nanocomposite were elucidated by FTIR, 1HNMR, TGA, DSC, TEM and DLS. These polymers were used as pour point depressant, flow improver and viscosity modifier and showed high efficiency. After comparison of the data of the polymers and their nanocomposite, the nanocomposite give the best results where the pour point decreased from 0 °C to − 18, − 27, − 24 and − 33 °C for CP1, CP2, NP1 and NP2 respectively at the optimum concentration 10,000 ppm. On the other hand the viscosity index increased from 86.57 to 93.25, 92.41, 94.17 and 93.103 for CP1, CP2, NP1 and NP2 respectively, the apparent viscosity increased from 55.863 to 69.31, 119.41, 111.28, and 166.89 cP also the yield stress increased from 652.19 to 1076.3, 1074 and 1480 D/cm2 for CP1, CP2, NP1 and NP2 respectively. [ABSTRACT FROM AUTHOR]

The influence of branched N, N′-bis(p-hydroxybenzoyl) containing propylenediamine (PDA) and triethylenetetramine (TETA) composites for corrosion inhibition of carbon steel in acidic solution (1 M HCl) was investigated using several quantum chemical, electrochemical impedance spectroscopy and potentiodynamic polarization as electrochemical techniques. The investigated molecules were posteriorly characterized by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FTIR) while the surfaces of carbon steel test coupons were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The obtained results revealed that the two amino compounds, N, N′-bis(p-hydroxybenzoyl) propanediamine (N, N′-HBPDA) and N, N′-bis(p-hydroxybenzoyl) triethylenetetramine (N, N′-HBTETA), have significant efficiency toward steel corrosion attack and its inhibition performance was significantly boosted by increasing concentration of di- and tetramine containing inhibitors. The two inhibitors achieved a maximum corrosion inhibition efficiency of 99.1% as indicated from polarization measurements. The isotherm feature of Langmuir adsorption appeared to be proper factor for associating the experimental gains with an applicable mechanism of inhibition process. The free energy ∆Gads was calculated to be − 27.5, 29.1 kJ/mol based on the adsorption isotherm model, indicating physical adsorption on the carbon steel surface. Further, images of the morphological analysis exhibited various features of attack owing to the aggressive medium and the employed concentration of the inhibitor. These synthesized amines supplied many favorable scores in the fabrication of functional mixed-type inhibitors. The computational studies reveal that N, N′-HBPDA and N, N′-HBTETA molecules could absorb via several lone pairs and π clouds, confirming their ability to be good corrosion inhibitors. [ABSTRACT FROM AUTHOR]

Three structurally different amino acids (Leucine, phenyl alanine and methionine) were reacted with oleic acid and polyethylene glycol (600) to give three nonionic surfactants (S 1 , S 2 and S 3 ). The chemical structures of the prepared surfactants were confirmed by FT-IR and 1 H, 13 CNMR. The surface parameters were calculated by surface tension measurements. The inhibition efficiencies of the prepared inhibitors on carbon steel in 1 M HCl were studied using polarization, and electrochemical impedance spectroscopy. Correlation between the quantum chemical calculations and inhibition efficiency was discussed. From the obtained results, the inhibitor based on L-phenyl alanine has high efficiency (94.14% at 1 × 10 − 3 mol L − 1 ) more than the other inhibitors. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Synthesis and applications of novel Schiff base derivatives as corrosion inhibitors and additives for improvement of reinforced concrete" published in Scientific Reports. The correction addresses errors in the affiliations of the authors. Ehab S. Gad's affiliation was incorrectly listed as 'Department of Chemistry, Faculty of Science (Men's Campus), Al-Azhar University, Nasr City 11884, Cairo, Egypt', but the correct affiliation is Chemistry Department, College of Science and Arts, Jouf University, Alqurayat, Saudi Arabia. The incorrect affiliation was also removed. The original article has been corrected. [Extracted from the article]

[Display omitted] • The anticorrosion effect of two inhibitors on C-steel in 1 M HCl was studied. • The polarization results show that (HBEDA) and (HBDETA) are mixed-type inhibitors. • The impedance data suggest the adsorption of the inhibitors on C-steel surface. • The Langmuir adsorption isotherm governs the adsorption mechanism. • QC and MC show that hetero atoms serve as active sites to facilitate adsorption. As part of the efforts made by many researchers to evaluate a lot of chemical compounds as inhibitors for carbon steel corrosion, this research focuses on novel two compounds of benzamide derivatives. The investigated compounds namely N, N -bis (p-hydroxybenzoyl) ethylenediamine (HBEDA) and N, N -bis (p-hydroxybenzoyl) Diethylenetriamine (HBDETA), were formulated then characterized using FTIR, 1HNMR, and elemental analysis to elucidate the structures chemically. Theoretical and experimental (electrochemical and morphology) studies made clear that (HBEDA) and (HBDETA) improve carbon steel (C-steel) inhibition efficiency in 1 M hydrochloric acid as concentrations increase (25, 50, 100, 150, 200, 250 ppm). The benzamide derivatives acted as interface corrosion inhibitors in an electrochemical impedance spectroscope (EIS) experiment, and they acted as mixed type corrosion inhibitors in a polarization test. They yielded best efficiency gains of 95.8 percent for HBEDA and 99.6 percent for HBDETA. Information collected from the EIS technique was studied in order to represent the corrosion inhibition procedure using an equivalent circuit (EC). The elevated K ads values and negative ΔG ads (-28.71, −28.79 kJ/mol) values of the two compounds (understudy) revealed that they were strongly and spontaneously adsorbed at C-steel/electrolyte connections respectively, and the adsorption isotherm of Langmuir fitted widely with the empirical data. The Surface examination (morphology) of metal employing energy dispersive X-ray (EDX) and scanning electron microscope (SEM) evaluations confirmed the adsorption of (HBEDA) and (HBDETA) on the substrate (C-steel). [ABSTRACT FROM AUTHOR]

Three novel cationic surfactants incorporated with 1,3,5-triethanolhexahydro-1,3,5-triazine moiety were prepared and characterized. The inhibition efficiency of the prepared surfactants toward the carbon steel in 1 M HCl solution was investigated by weight loss, electrochemical polarization, and electrochemical impedance spectroscopy techniques. The maximum obtained efficiency was exhibited by N-dodecyl-1,3,5 tris (2-Hydroxypropane)1,3,5 triazinyl N-dodecylammonium bromide (DODT) against the three used techniques. The efficiencies were 97.0%, 94.4%, and 91.07%, respectively. The surface active properties for these surfactants were investigated. The quantum chemical parameters were also calculated. The data was discussed in light of surface active, corrosion inhibition, and quantum chemical properties to characterize the adsorption mechanism. [ABSTRACT FROM PUBLISHER]