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1.
Two series of Schiff base amphiphiles were prepared by condensation of benzaldehyde or anisaldehyde with three different alkyl chain length fatty amines namely: dodecyl, hexadecyl and octadecyl amine. The chemical structures of the prepared Schiff bases were confirmed by using different techniques, (elemental analysis, FTIR and 1H-NMR spectra). The data of structural analysis for these compounds were confirmed by the purity of the synthesized amphiphiles. The synthesized Schiff bases were evaluated as corrosion inhibitors for low carbon steel (mild steel) in various acidic media (HCl and H2SO4) using a weight loss technique. The corrosion inhibition measurements of these inhibitors showed high protection against corrosion process in the tested acidic media at different doses (50, 100, 150 and 200 ppm) as well as their having a good biocidal effect against sulphate reducing bacteria. The discussion correlated the efficient corrosion inhibition of these inhibitors to their chemical structures. 相似文献
2.
The corrosion and passivation behaviors of alloys with different Cu–Ni ratios were investigated in acidic sulfate solutions. The corrosion rate was calculated and the corrosion inhibition process was investigated using different amino acids as corrosion inhibitors. For these investigations conventional electrochemical techniques and electrochemical impedance spectroscopy (EIS) were used. Fitting of the experimental impedance data to theoretical values enables understanding of the corrosion inhibition mechanism and the suggestion of a suitable electrical model to explain the behavior of the alloys under different conditions. The investigation of the electrochemical behavior of alloys before and after the corrosion inhibition processes has shown that some amino acids like lysine have promising corrosion inhibition efficiency at very low concentrations. A model for the electrode/electrolyte interface during the corrosion inhibition processes was suggested and the validity of the model for the explanation of the corrosion inhibition phenomena was discussed. 相似文献
3.
Selected triazole derivatives have been synthesised and evaluated as corrosion inhibitors for mild steel in natural aqueous environment by weight loss, potentiodynamic polarisation and ac impedance methods. All the condensed products showed good inhibition efficiency (IE). The effect of changing functional groups of some triazole derivatives on their inhibition efficiency was also reported using weight loss and potentiodynamic technique. 3-Salicylalidene amino-1,2,4-triazole phosphonate (SATP) was found to be the best corrosion inhibitor compare to the other compounds. Surface analysis was carried out to establish the mechanism of corrosion inhibition of mild steel in neutral aqueous media. 相似文献
4.
A. Ali Fathima Sabirneeza R. Geethanjali S. Subhashini 《Chemical Engineering Communications》2013,200(2):232-244
Several works have been reported on the corrosion inhibition of different metals in various corrosive environments. Initially attention was centered on organic compounds but later focused on green inhibitors. Green inhibitors include nontoxic, eco-friendly polymers and natural inhibitors. In recent years, there has been increased emphasis on applications of polymers, copolymers, grafted polymers, and polymer composites as green corrosion inhibitors. The prime controlling factors influencing the corrosion inhibitive performance of polymeric compounds on the corrosion of metals in various corrosive environments are discussed in this review. The superior performance of a polymeric corrosion inhibitor is due to its larger size and greater number of functional anchoring groups. Through the anchoring groups the polymers easily get adsorbed on the metal surface and cover considerably more surface than the corresponding monomers. The main factors influencing the corrosion mitigating properties of the polymers are molecular size, weight, composition, and nature of the anchoring groups. The solution pH, concentration, exposure time, and temperature also find their role in inhibition performance. In this review, we have tried to cover various types of polymeric corrosion inhibitors for iron and its alloys. 相似文献
5.
A comparative study of 5-amino-1,2,4-triazole (5-ATA), 5-amino-3-mercapto-1,2,4-triazole (5-AMT), 5-amino-3-methylthio-1,2,4-triazole (5-AMeTT) and 1-amino-3-methylthio-1,2,4-triazole (1-AMeTT) as inhibitors for mild steel corrosion in 0.1 M HCl solution at 20 °C was carried out. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behaviour in the absence and presence of different concentrations of these inhibitors under the influence of various experimental conditions. Measurements of open circuit potential (OCP) as a function of time till reaching the steady-state potentials (Est) were also established. The studies have shown that 5-AMT was the most efficient inhibitor reaching values of inhibition efficiency (IE%) up to 96% at a concentration of 10−3 M. Polarization curves showed that the four studied compounds act as mixed inhibitors. The potential of zero charge (PZC) of mild steel was determined in 0.1 M HCl in the absence and presence of the studied inhibitors. The effect of chemical structure of the four tested inhibitors was discussed. Results obtained from OCP versus time, polarization and impedance measurements are in good agreement. 相似文献
6.
Ismail A. Aiad Salah M. Tawfik Samy M. Shaban Ali A. Abd-Elaal Mohamed El-Shafie 《Journal of surfactants and detergents》2014,17(3):391-401
It is well known that tetra hydroxymethyl phosphonium sulfate (THPS) is commonly used in oil fields as a biocide for sulfate-reducing bacteria (SRB), but it has low corrosion inhibition. In this study, four phosphonium surfactant compounds were synthesized via a coupling reaction between THPS and different fatty acids namely: decanoic, dodecanoic, palmitic and stearic acids to produce the corresponding surfactants. The chemical structure of the synthesized surfactants was confirmed using FTIR and 1H-NMR spectroscopy. The surface activity of the prepared compounds was determined by surface tension measurements. The critical micelle concentration (CMC) of each surfactant compound was determined. The corrosion inhibition of the synthesized compounds on carbon steel in 0.5 M HCl was studied by weight loss measurements, potentiodynamic and electrochemical impedance spectroscopy. The effect of the inhibitor concentration and hydrophobic chain length on the their efficiency was also studied. It was found that the CMC of each compound depends on its chemical structure. It was also found that the corrosion inhibition efficiency depends on both of concentration and molecular structure of the inhibitors. Polarization curves revealed that the inhibitors used represent mixed-type inhibitors, which hinder the cathodic and anodic parts of the corrosion reaction in acidic media. Adsorption of used inhibitors leads to a reduction in the double layer capacitance and an increase in the charge transfer resistance. Also the biocidal effect of these compounds was enhanced. 相似文献
7.
8.
A variety of surface active compounds were synthesized by the quaternization of some straight chain amide derivatives with triethylamine or pyridine. Their structure FT-IR and 1H-NMR spectra were recorded. In addition their physical properties and corrosion prevention efficiencies were investigated. All compounds were tested with steel coupons in acidic media by the gravimetric method. As acidic media 1.5 M HCl and 1.5 M H2SO4 were used and the corrosion inhibition tests fulfilled at room temperature for 24 h. Almost all prepared cationic surfactants showed efficient inhibition around their critical micelle concentrations. The effects of HCl concentration on corrosion inhibition of some synthesized compounds were also investigated. The corrosion tests were supported by contact angle measurements. 相似文献
9.
Nabel A. Negm Mohamad F. Zaki Mounir A. I. Salem 《Journal of surfactants and detergents》2009,12(4):321-329
A novel series of cationic surfactants containing Schiff base groups were synthesized by condensation of fatty amines namely:
dodecyl, tetradecyl, hexadecyl and octadecyl amine and 4-diethyl aminobenzaldehyde. The chemical structures of these surfactants
were confirmed using elemental analysis, FTIR spectra, 1H-NMR and atomic absorption spectroscopy. Surface properties of the synthesized compounds were determined using surface tension
techniques. The results of the surface tension measurements showed good surface behaviors of these compounds in their aqueous
solutions. The surface activities were found to be greatly influenced by the chemical structures of the synthesized compounds.
The synthesized cationic Schiff bases were evaluated as corrosion inhibitors for carbon steel in different acidic media (HCl
and H2SO4) at different doses (400, 200, 100, 50, 25 ppm). The corrosion inhibition efficiencies of these inhibitors were calculated
using the corrosion rates of the carbon steel in the studied media and found in the acceptable range of the commercially used
inhibitors. Also the chemical structure of these inhibitors was found of great influence on their inhibiting efficiency. 相似文献
10.
Non‐substituted or mono‐substituted 11‐cyano or 11‐thiocyanato undecanoic acid phenylamide derivatives were synthesized and characterized with their FT‐IR and 1H‐NMR spectra. Thereafter, their corrosion prevention efficiencies were investigated. All compounds were tested with steel coupons in acidic medium by a gravimetric method. Acidic tests were done with a medium concentration of 2 M HCl for 5 h at variable temperatures and inhibitor concentrations. The corrosion prevention efficiencies of the inhibitors were compared according to their chemical structures and the corrosion inhibition mechanism was also discussed. The synthesized compounds showed promising corrosion inhibition efficiencies under the outlined test conditions. Best inhibitions were obtained at 27°C and 100 ppm concentration of corrosion inhibitors. 相似文献
11.
Bis[N,N′-(alkylamideethyl)ethyl] triethylenediamine surfactants are quaternary ammonium salt Gemini surfactants with amide, which
are synthesized from fatty acid (dodecanoic, hexadecanoic, tetradecanoic and octadecanoic) methyl esters, triethylene tetramine
and ethyl bromide. The chemical structures of the prepared compounds were characterized by elemental analysis, FTIR and 1H-NMR spectra, melting point and Krafft point. Several properties of the synthesized surfactants were studied including surface
tension, critical micelle concentration, interfacial tension, emulsification power, salt effect, corrosion inhibition efficiency
and biological activity. The results show that the surface activity, critical micelle concentration and interfacial activity
are correlated to their chemical structures. The emulsification power measurements of these surfactants show their low emulsifying
tendency towards Tazhong’s crude oil from Tarim Oilfield. The synthesized surfactants also exhibit high biocidal activity
towards Gram-positive and Gram-negative bacteria and fungi. This activity increases with the increase of alkyl chain length.
The corrosion measurement of these surfactants in acidic media with a weight loss technique show good protection of mild steel
alloys against acidic environments. These properties suggest that the synthesized compounds have potential for application
in the oilfield area. 相似文献
12.
13.
Serkan Öztürk Ayhan Yıldırım Mehmet Çetin Mustafa Tavaslı 《Journal of surfactants and detergents》2014,17(3):471-481
New cationic surfactants were synthesized by the quaternization of a number of straight-chain amide derivatives with triethylamine or pyridine. The corrosion inhibition tests of the surface-active compounds were performed at room temperature for 24 h on carbon steel coupons in acidic media using the gravimetric method. The acidic media used were 1.5 M HCl and 1.5 M H2SO4. Almost all of the synthesized cationic surfactants showed efficient inhibition of corrosion in the test. To establish the inhibition efficiencies of the inhibitors, surface characterization studies (contact angle measurements, SEM analysis and optical profilometer images) of the metal coupons used were performed. 相似文献
14.
Ali A. Abd-Elaal Ismail Aiad Samy M. Shaban Salah M. Tawfik Atef Sayed 《Journal of surfactants and detergents》2014,17(3):483-491
Three compounds namely; 5-(phenyl)-4H-1,2,4-triazole-3-thiol, 3-(decylthio)-5-phenyl-1H-1,2,4-triazole and 3-(benzylthio)-5-phenyl-1H-1,2,4-triazole) were synthesized. The chemical structure of the prepared compounds was confirmed using FTIR and 1H-NMR analysis. The compounds were tested as corrosion inhibitors against the corrosion of carbon steel in 1 M HCl using weight loss, polarization and electrochemical impedance methods. The results revealed that these compounds have significant inhibiting effects on the corrosion of carbon steel. Polarization studies showed that the compounds act as mixed-type inhibitors which retard the anodic and the cathodic reactions with a predominant effect towards the cathodic reaction. The prepared compounds were evaluated as antimicrobial agents against sulfate-reducing bacteria using the serial dilution method, which showed good biocidal action. 相似文献
15.
Maged A. El Sawy Maram M. Elshatanofy Yeldez El Kilany Kamal Kandeel Bassma H. Elwakil Mohamed Hagar Mohamed Reda Aouad Fawzia Faleh Albelwi Nadjet Rezki Mariusz Jaremko El Sayed H. El Ashry 《International journal of molecular sciences》2022,23(9)
Tuberculosis (TB) caused by Mycobacterium tuberculosis is still a serious public health concern around the world. More treatment strategies or more specific molecular targets have been sought by researchers. One of the most important targets is M. tuberculosis’ enoyl-acyl carrier protein reductase InhA which is considered a promising, well-studied target for anti-tuberculosis medication development. Our team has made it a goal to find new lead structures that could be useful in the creation of new antitubercular drugs. In this study, a new class of 1,2,3- and 1,2,4-triazole hybrid compounds was prepared. Click synthesis was used to afford 1,2,3-triazoles scaffold linked to 1,2,4-triazole by fixable mercaptomethylene linker. The new prepared compounds have been characterized by different spectroscopic tools. The designed compounds were tested in vitro against the InhA enzyme. At 10 nM, the inhibitors 5b, 5c, 7c, 7d, 7e, and 7f successfully and totally (100%) inhibited the InhA enzyme. The IC50 values were calculated using different concentrations. With IC50 values of 0.074 and 0.13 nM, 7c and 7e were the most promising InhA inhibitors. Furthermore, a molecular docking investigation was carried out to support antitubercular activity as well as to analyze the binding manner of the screened compounds with the target InhA enzyme’s binding site. 相似文献
16.
Two kinds of diols containing 1,2,3-triazole units were synthesized through the azide-alkyne cycloaddition reaction between propargyl alcohol and 1,4-diazidobutane. One of the diols, (butane-1,4/1,5-diylbis[1H-1,2,3-triazole-1,4/1,5-diyl])dimethanol (BDTDO-1), containing 1,4/1,5-disubstituted 1,2,3-triazole regioisomers, was directly prepared under thermal condition without Cu(I) catalyst. The other diol, (butane-1,4-diylbis[1H-1,2,3-triazole-1,4-diyl])dimethanol (BDTDO-2), containing 1,4-disubstituted 1,2,3-triazoles, was prepared by Cu(I) catalyzed click chemistry. Then, two kinds of 1,2,3-triazole modified polyurethane elastomers (PUEs) were prepared from the reaction of 4,4′-methylenebis(phenyl isocyanate) and poly(tetramethylene ether) glycol, with BDTDO-1 or BDTDO-2 as the chain extender (CE). It was found that the introduction of 1,2,3-triazoles and their substitution positions had significant influences on the hydrogen bonding, thermal and mechanical properties of PUEs. Compared with the PUE prepared from 1,4-butanediol as the CE, the PUE containing symmetric 1,4-disubstituted 1,2,3-triazoles units in the main chains shows higher values of hydrogen bonding, physical crosslinking density, Young's modulus, tensile strength and melting temperature, while lower glass transition temperature, resulting from the rigid structure and the ability to form more hydrogen bonds. However, the introduction of asymmetric 1,4/1,5-disubstituted 1,2,3-triazole moieties decreases the values of hydrogen bonding, thermal and mechanical properties of PUE appreciably due to the destruction of the ordered structure of the hard segments. 相似文献
17.
D. D. N. Singh M. M. Singh R. S. Chaudhary C. V. Agarwal 《Journal of Applied Electrochemistry》1980,10(5):587-592
The inhibitive efficiencies of isatin, thiosemicarbazide and their condensation product, i.e. isatin-3-(3-thiosemicarbazone) are studied at different concentrations in relation to corrosion of aluminium alloys (1060,1100, 3003) in 20% nitric acid at 30, 40 and 50° C using the weight loss method. Polarization experiments have been performed at 0.05, 0.2 and 0.3% concentrations of the inhibitors at 30° C. It is found that isatin-3-(3-thiosemicarbazone) is a more effective inhibitor as compared to the parent compounds for the three alloys at all the experimental temperatures. The effectiveness of the inhibitors increases with increase in temperature from 30° C to 50° C. The inhibitors are found to retard the corrosion by predominantly acting on local cathodes although they are also partially effective on the anodes. The critical current density for the passivation of aluminium decreases almost in the same order as the inhibition efficiency of the inhibitors increases. 相似文献
18.
Elena Messina Chiara Giuliani Marianna Pascucci Cristina Riccucci Maria Paola Staccioli Monica Albini Gabriella Di Carlo 《International journal of molecular sciences》2021,22(19)
The protection of metals from atmospheric corrosion is a task of primary importance for many applications and many different products have been used, sometimes being toxic and harmful for health and the environment. In order to overcome drawbacks due to toxicity of the corrosion inhibitors and harmful organic solvents and to ensure long-lasting protection, new organic compounds have been proposed and their corrosion inhibition properties have been investigated. In this work, we describe the use of a new environment-friendly anticorrosive coating that takes advantage of the synergism between an eco-friendly bio-polymer matrix and an amino acid. The corrosion inhibition of a largely used Copper-based (Cu-based) alloy against the chloride-induced indoor atmospheric attack was studied using chitosan (CH) as a biopolymer and l-Cysteine (Cy) as an amino acid. To evaluate the protective efficacy of the coatings, tailored accelerated corrosion tests were carried out on bare and coated Cu-based alloys, further, the nature of the protective film formed on the Cu-based alloy surface was analyzed by Fourier-transformed infrared spectroscopy (FTIR) while the surface modifications due to the corrosion treatments were investigated by optical microscopy (OM). The evaluation tests reveal that the Chitosan/l-Cysteine (CH/Cy) coatings exhibit good anti-corrosion properties against chloride attack whose efficiency increases with a minimum amount of Cy of 0.25 mg/mL. 相似文献
19.
The inhibiting properties of two synthesized metals (alkyl)-2-hydroxy benzene sulfonate compounds have been studied on the corrosion of steel (St-3) in aerated 0.1N H2SO4 solutions by potentiodynamic polarization (dc) technique and electrochemical impedance spectroscopy (ac). The polarization curves indicate that the inhibitors are mixed-type. The impedance increases with inhibitors concentration. Low difference in inhibition efficiencies of two compounds for the corrosion of St-3 steel could be explained by high similarities of their structures. Results obtained by both electrochemical methods are in relatively good agreement. 相似文献
20.
Yong-Ming Tang Yun Chen Wen-Zhong Yang Ying Liu Xiao-Shuang Yin Jin-Tang Wang 《Journal of Applied Electrochemistry》2008,38(11):1553-1559
2,5-Bis(2-thienyl)-4-amino-1,2,4-triazole (2-TAT) and 2,5-bis(3-thienyl)-4-amino-1,2,4-triazole (3-TAT) have been studied
as inhibitors for the corrosion of copper in 0.5 M H2SO4 using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The inhibition efficiency of the triazole
compounds increases with increasing concentration, and the effect of 3-TAT is better than that of 2-TAT with the same concentration.
Potentiodynamic polarization measurements indicate the triazole compounds act as mixed type inhibitors in 0.5 M H2SO4. The adsorption of the triazole compounds is found to obey the Langmuir adsorption isotherm. High significant correlations
for the triazole compounds are obtained between inhibition efficiency and quantum chemical parameters (R = 0.975) using the quantitative structure–activity relationship (QSAR) method. 相似文献