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1 – 10 of over 1000Yanhua Zhu, Liqiang Zhao, Pingli Liu and Xiao Qu
In this work, a kind of Mannich base (C21H25NO) was synthesized with cinnamal aldehyde, acetophenone and diethylamine in a condensing reflux device based on the conventional…
Abstract
Purpose
In this work, a kind of Mannich base (C21H25NO) was synthesized with cinnamal aldehyde, acetophenone and diethylamine in a condensing reflux device based on the conventional method. Optimization of the inhibitor concentration was explored.
Design/methodology/approach
Spectral properties of this compound was investigated by FTIR, and its inhibition efficiency and mechanism on N80 steel in 20% hydrochloric acid solution were studied by weight loss measurement, electrochemical measurement (potentiodynamic polarization and electrochemical impedance spectroscopy) and surface analytical measurement (scanning electron microscope with energy dispersive spectrometer).
Findings
The results showed that the new inhibitor reduced the double-layer capacitance and increased the charge transfer resistance. The inhibition efficiency is 99.7% when the concentration of C21H25NO is 3%. The adsorption of C21H25NO on N80 steel surface in 20% HCl solution was found to be spontaneous and steady. Observed from the steel surface, an inhibition film was confirmed to be presented after adding inhibitor and successfully hindered the corrosive ions from reaching the bulk steel.
Originality/value
A new Mannich base (C21H25NO) was synthesized by cinnamal aldehyde, acetophenone and diethylamine for the corrosion prevention of N80 steel in 20% hydrochloric acid solution.
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Pingli Liu, Yanhua Zhu and Liqiang Zhao
A novel compound was synthesized by cyclohexylamine, acetophenone and cinnamaldehyde through Mannich reaction in laboratory to use as corrosion inhibitor for steel in…
Abstract
Purpose
A novel compound was synthesized by cyclohexylamine, acetophenone and cinnamaldehyde through Mannich reaction in laboratory to use as corrosion inhibitor for steel in acidification process.
Design/methodology/approach
The corrosion and inhibition of 13Cr stainless steel in conventional acidification solution were investigated by electrochemical measurements and soaking experiments. The corrosion appearance was observed with scanning electron microscope on the whole surface of 13Cr stainless steel in 20% HCl solution, and the protection film was confirmed on the surface in presence with inhibitor.
Findings
Results manifested that the inhibitor C23H27NO can effectively inhibit the corrosion reaction by forming an adsorption layer function as a barrier. Polarization curves indicated that the mixed inhibitor can reduce anodic dissolution and cathodic hydrogen evolution reactions simultaneously. The results of impedance measurements indicated that this inhibitor cannot change the corrosion mechanism of 13Cr stainless steel in 20% HCl solution. The results of the study can provide a theoretical basis for the application of 13Cr stainless steel in conventional acidification solutions during oil well acidification construction process.
Originality/value
A novel compound was synthesized by cyclohexylamine, acetophenone and cinnamaldehyde through Mannich reaction in laboratory to use as corrosion inhibitor for steel in acidification process. The corrosion and anti-corrosion mechanism of 13Cr steel in acid solution was proposed.
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G. Bereket, A. Pınarbaşı and C. Öğretir
The effect of benzimidazole‐2‐tione and benzoxazole‐2‐tione derivatives on the corrosion of aluminium in 0.1 M HCl has been investigated by a potentiostatic polarisation…
Abstract
The effect of benzimidazole‐2‐tione and benzoxazole‐2‐tione derivatives on the corrosion of aluminium in 0.1 M HCl has been investigated by a potentiostatic polarisation technique. Inhibition efficiencies were found to follow the order: benzimidazole‐2‐tione > 5‐methyl benzimidazole‐2‐tione > 5‐chloro benzimidazole‐2‐tione, while that of benzoxazole‐2‐tione derivatives were found to follow the order: 5‐methyl benzoxazole‐2‐tione > benzoxazole‐2‐tione > 5‐chloro benzoxazole‐2‐tione > 5‐nitro benzoxazole‐2‐tione. The inhibitive action of these heterocyclic compounds was mainly due to adsorption on the metal surfaces, which show parallelism with the calculated total negative charge of each of the molecules. Thermodynamic parameters, such as values of free energies of adsorption ΔGads and values of equilibrium constants Kads, were determined. Activation energies Ea, activation enthalpies ΔH* and activation entropies ΔS* were determined from the corrosion currents measured at different temperatures.
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G. Bereket and A. Yurt
Potentiodynamic polarisation studies were carried out on the inhibition of low carbon steel in 0.1M hydrochloric acid solution over the temperature range 20‐60°C at different…
Abstract
Potentiodynamic polarisation studies were carried out on the inhibition of low carbon steel in 0.1M hydrochloric acid solution over the temperature range 20‐60°C at different inhibitor concentrations by various quaternary ammonium salts and cationic surfactants. The inhibitors examined were tetraethyl ammonium chloride, tetrabutyl ammonium chloride, benzyltrimethyl ammonium chloride, benzyltriethyl ammonium chloride, benzyltributyl ammonium chloride, phenyltrimethyl ammonium chloride, alkylbenzyldimethyl ammonium chloride, tetradecyltrimethyl ammonium bromide and cetyltrimethyl ammonium bromide. Maximum inhibition efficiencies of cationic surfactants were observed around and above critical micelle concentration (cmc), while the inhibition efficiencies of the quaternary ammonium salts were found to increase with the increase in their concentrations. The degree of shift in Ecorr value, together with change in anodic and cathodic Tafel slopes (ba, bc), revealed that cationic surfactants behave as an anodic inhibitor, while quaternary ammonium salts behave as mixed type inhibitors. Inhibition efficiencies of studied inhibitors seem to be closely related with the chain length of the alkyl group as well as the presence of benzene ring in quaternary ammonium compounds. Thermodynamic and kinetic parameters for dissolution and adsorption were also calculated.
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G. Bereket, A. Yurt and H. Türk
The inhibiting effects of 2,6‐ionen and 2,10‐ionen type polyvinylbenzyltrimethylammonium chloride, and latex, on low carbon steel in hydrochloric acid solution was investigated by…
Abstract
The inhibiting effects of 2,6‐ionen and 2,10‐ionen type polyvinylbenzyltrimethylammonium chloride, and latex, on low carbon steel in hydrochloric acid solution was investigated by potentiodynamic polarisation measurements and impedance measurement techniques over the temperature range of 20‐60°C at different inhibitor concentrations. It was found that the inhibition efficiencies increased with increasing inhibitor concentration. The degree of shift in Ecorr values, together with the change in anodic and cathodic Tafel slopes (βa, βc), revealed that the studied inhibitors behaved as anodic inhibitors. Thermodynamic and kinetic parameters for dissolution and adsorption were also calculated.
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Teofil Jesionowski, Magdalena Nowacka and Filip Ciesielczyk
The purpose of this paper is to characterise the electrokinetic properties of pigments supported on both unmodified and modified silica. The paper describes the preparation of…
Abstract
Purpose
The purpose of this paper is to characterise the electrokinetic properties of pigments supported on both unmodified and modified silica. The paper describes the preparation of hybrid pigments via adsorption of organic dyes on silica supports and determination of the zeta potential and electrophoretic mobility of the materials obtained.
Design/methodology/approach
The materials studied were hybrid pigments obtained as a result of adsorption of two basic dyes: C.I. Basic Red 1 and C.I. Basic Orange 14 and one acidic dye C.I. Mordant Red 3 from solutions of concentrations of 500, 2,000 and 3,000 mg/dm3 on the surface of both unmodified and modified silica supports. The agent used for modification of the silica surface was N‐2‐(aminoethyl)‐3‐aminopropyltrimethoxysilane.
Findings
The modification of the silica surface with aminosilane was found to change, significantly, the electrokinetic character of the inorganic support. This change was interpreted as being due to the ionisation of −NH2 groups from the modifier molecule, which changes the surface charge. Electrokinetic curves of the pigment composites changed considerably as a function of the type and concentration of the organic dye adsorbed.
Research limitations/implications
Only SiO2 supports (unmodified and aminosilane‐grafted) and C.I. Basic Red 1, C.I. Basic Orange 14 or C.I. Mordant Red 3 dyes adsorbed on its surface were evaluated. Other dyes could also be studied.
Practical implications
Measurements of the zeta potential were used to characterise the stability of colloidal dispersions of paints or dyes and to control the stability of paints on storage and their performance on painting and drying.
Originality/value
The paper demonstrates that the measurements of zeta potential permit determination of the optimum conditions for the use of a given pigment. The finding of the change of the zeta potential of a given pigment and so, also its application properties as a result of different functional groups in the dye or the modifying agent molecules.
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In recent years the Russians have experienced trouble with rapid corrosion in the oil industry, especially with sulphur oils in the low‐temperature equipment used for dealing with…
Abstract
In recent years the Russians have experienced trouble with rapid corrosion in the oil industry, especially with sulphur oils in the low‐temperature equipment used for dealing with gasoline distillates. This matter is the subject of a long article by L. D. Zakharochkin et al. in the Fuel & Oil Journal (Khim. i Tek1in. Topliva i Masel, 1959, 3, 46–52). The following is a digest of the article.
Ibrahim A. Amar and Mohammed M. Ahwidi
This paper aims to investigate the electrocatalytic activity of CoFe1.9Mo0.1O4-Ce0.8Gd0.18Ca0.02O2-δ composite (CFMo-CGDC) for the direct synthesis of ammonia from H2O and N2…
Abstract
Purpose
This paper aims to investigate the electrocatalytic activity of CoFe1.9Mo0.1O4-Ce0.8Gd0.18Ca0.02O2-δ composite (CFMo-CGDC) for the direct synthesis of ammonia from H2O and N2 under atmospheric pressure.
Designs
CoFe1.9Mo0.1O4 nanoparticles (CFMo NPs) were synthesized via a sol-gel method. CFMo NPs were characterized using X-ray diffraction (XRD), Brunauer–Emmet–Teller (BET) specific surface area measurement and scanning electron microscope (SEM). Double-chamber reactor was used to synthesize ammonia using H2O and N2 as precursors. The factors affecting the ammonia formation rate (applied voltage and temperature) were studied.
Findings
CoFe1.9Mo0.1O4 nanoparticles (CFMo NPs) were synthesized via a sol-gel method. CFMo NPs were characterized using XRD, Brunauer–Emmet–Teller (BET) specific surface area measurement and SEM. Double-chamber reactor was used to synthesize ammonia using H2O and N2 as precursors. The factors affecting the ammonia formation rate (applied voltage and temperature) were studied.
Originality/value
The usage of CFMo-CGDC composite as an electrocatalyst for the synthesis of ammonia directly from H2O and N2.
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A.A. El‐Sanabary, M.M. Elnashar, A. Abdallah Magda and B.M. Badran
Soybean oil was epoxidized in situ under established conditions. The produced epoxidized soybean oil was subjected to a sulfur containing compound of the formula…
Abstract
Soybean oil was epoxidized in situ under established conditions. The produced epoxidized soybean oil was subjected to a sulfur containing compound of the formula (5‐phenyl‐1,3,4‐oxadiazole‐2‐(3H)‐thiones) and four of its derivatives (p‐chloro‐, p‐iodo‐, p‐methyl‐ and p‐methoxy‐) in sealed ampoules under inert atmosphere at 180‐2308C (according to the melting point of each sulfur compound). The produced adducts were added to three varnishes based on alkyd resin, chlorinated rubber and a vinyl chloride copolymer to evaluate them as corrosion inhibitors for steel surfaces. It was found that these adducts can act as good corrosion inhibitors and their efficiencies depend principally on the substituted functional group.
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Murat Isik, Isa Emami Tabrizi, Raja Muhammad Awais Khan, Mehmet Yildiz, Eda Aydogan and Bahattin Koc
In recent years, additive manufacturing (AM) has started to be used for manufacturing real functional parts and assemblies for critical applications in aerospace, automotive, and…
Abstract
Purpose
In recent years, additive manufacturing (AM) has started to be used for manufacturing real functional parts and assemblies for critical applications in aerospace, automotive, and machinery industries. Most complex or assembled parts require internal features (IF) such as holes, channels, slots, or guides for locational and mating requirements. Therefore, it is critical to understand and compare the structural and mechanical properties of additively manufactured and conventionally machined IFs.
Design/methodology/approach
In this study, mechanical and microstructural properties of Inconel 718 (Inc718) alloy internal features, manufactured either as-built with AM or machining of additively manufactured (AMed) part thereafter were investigated.
Findings
The results showed that the average ultimate tensile strength (UTS) of additively manufactured center internal feature (AM-IF) is almost analogous to the machined internal feature (M-IF). However, the yield strength of M-IF is greater than that of AM-IF due the greater surface roughness of the internal feature in AM-IF, which is deemed to surpass the effect of microstructure on the mechanical performance. The results of digital image correlation (DIC) analysis suggest that AM-IF and M-IF conditions have similar strain values under the same stress levels but the specimens with as built IF have a more locally ductile region around their IF, which is confirmed by hardness test results. But this does not change global elongation behavior. The microstructural evolution starting from as-built (AB) and heat-treated (HT) samples to specimens with IF are examined. The microstructure of HT specimens has bimodal grain structure with d phase while the AB specimens display a very fine dendritic microstructure with the presence of carbides. Although they both have close values, machined specimens have a higher frequency of finer grains based on SEM images.
Originality/value
It was shown that the concurrent creation of the IF during AM can provide a final part with a preserved ultimate tensile strength and elongation but a decreased yield strength. The variation in UTS of AM-IF increases due to the surface roughness near the internal feature as compared to smooth internal surfaces in M-IF. Hence, the outcomes of this study are believed to be valuable for the industry in terms of determining the appropriate production strategy of parts with IF using AM and postprocessing processes.
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