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Abstract Nine phosphonates surfactant were synthesized by two steps. The first step was condensation between acetaldehyde and butyl amine, dodecylamine or hexadecylamine individually to give three corresponding Schiff bases, and then the Schiff base products were added to dibutyl phosphite individually. The second step was reaction of the phosphonate products with polyethylene glycol 400, 600 and 1000 to get on the nine water soluble phosphonate corrosion inhibitors. The products were characterized by FTIR, 1HNMR and 13CNMR spectroscopic techniques. The surface active properties of this phosphonate were calculated and they were evaluated as corrosion inhibitors in formation water formulations using open circuit potential and potentiodynamic polarization. The quantum calculations of the structures were calculated and the data obtained were nearly closed with the experimental data. HMPA1 shows the best results as corrosion inhibitors (efficiency 94%) at lowest concentration 15 ppm. The corrosion inhibition mechanism was discussed on the basis of surface tension measurements and the electronic data. Graphical abstract Unlabelled Image Highlights • Nine novel phosphonates were synthesized and characterized by spectroscopic methods. • Electrochemical techniques were used to evaluate as corrosion inhibitors. • Quantum was applied to the synthesized phosphonate to predict their efficiencies. • The percentage inhibition efficiency (IE%) of the surfactants increases by decrease the alkyl chain and the ethylene units. [ABSTRACT FROM AUTHOR]

Abstract A newly anionic surfactant; namely (2Z,2′Z)-4,4′-(ethane-1,2-diylbis((2-((4-dodecylphenyl)sulfonamido)ethyl)azanedinyl)bis(4-oxobut-2enoate), desined as Tetra-anionic surfactant was synthesized. Its chemical structure was confirmed by FTIR and 1HNMR spectroscopic techniques. The corrosion mitigation behavior of the prepared surfactant for mild steel (MS) in high saline synthetic water was monitoring by chemical technique (weight loss), electrochemical techniques (Tafel and EIS). The obtained results showed that the corrosion resistance has been improved after the addition of the surfactant molecules. The inhibition efficiency grown up with the inhibitor concentration reaching the maximum at concentration 120 ppm, where the IE% values were 84, 82, and 79.5% in cases of weight loss, Tafel and EIS techniques, respectively. The mixed-type inhibitor with permanent anodic effect can be inferred from polarization data of mild steel in the presence of different concentration of Tetra- compound. The corrosion protection performance of the used inhibitor was related to its adsorption ability on the MS surface. The adsorption of Tetra-molecules increased the charge transfer resistance of MS. The adsorption process of the tested corrosion inhibitor obeyed Langmuir adsorption isotherm. The corrosion and scale produced layer formed on the mild steel surface in absence and presence of the insight anionic surfactant was depicted by SEM. The chemical analysis of this layer was examined by EDX, and show the corrosion and Ca- scale inhibition performance of Tetra- molecules. Quantum chemical calculations were compatible with the experimental results. [ABSTRACT FROM AUTHOR]

Two of ethoxylated tolyltriazole non ionic surfactants namely; TTA (12) and TTA (24) were synthesized (where 12 and 24 are the number of ethylene oxide units groups bonded to tolyltriazole molecule). The chemical structure of the synthesized compounds was confirmed by FTIR and 1 H NMR spectroscopic techniques. The performance of the two synthesized tolyltriazole derivatives was evaluated as corrosion inhibitors for Cu-10Al alloy in seawater and compared with the performance of tolyltriazole (TTA). Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used in this evaluation. The results showed enhancement in inhibition efficiency with increasing the number of ethylene oxide units in the surfactant molecule. Potentiodynamic polarization data showed that the surfactants under investigation act as mixed type inhibitors. Also it was found that the inhibition efficiency increased by addition of Cu 2+ ions to the solution containing inhibitor and reached to 97%. This behavior can be attributed to the synergistic effect between Cu 2+ ions and inhibitor. The data obtained from EIS were analyzed to give a suitable equivalent circuit (EC). Finally, the surface morphology of Cu-10Al alloy immersed in sea water in the absence and presence of inhibitor molecule was examined by SEM images to through some light on the nature of the protective layer formed on the surface that isolate it from the aggressive environment. [ABSTRACT FROM AUTHOR]

In this study, the inhibition effect of 2,2′-(heptane-1,7-diylbis(azanylylidene)bis-(methanylylidene))diphenol (HAMD) on carbon steel corrosion in 0.5 mol L −1 H 2 SO 4 solution was studied. Weight loss and electrochemical techniques such as open circuit potential (OCP), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used to inspect the efficiency of HAMD as corrosion inhibitor. Scanning electron microscopy (SEM) and energy dispersion X-ray (EDAX) were used to characterize the steel surface. Polarization measurements indicated that, the studied inhibitor acts as mixed-type inhibitor. The adsorption of HAMD molecules on the carbon steel surface obeys Langmuir adsorption isotherm. [ABSTRACT FROM AUTHOR]

Abstract: The effect of non-ionic surfactant, namely N,N-di(poly oxy ethylene) amino lauryl amide, on the corrosion rate of carbon steel in produced water has been investigated by various corrosion monitoring techniques. The strong adsorption ability of the surfactant molecules leads to formation of a mono-layer, which isolates the surface from the environment and thereby reduces the corrosion attack on the surface. The adsorption process was found to obey the Langmuir adsorption isotherm. The potentiostatic polarization results clearly revealed that the inhibitor behaves as a mixed type. The maximum percentage inhibition efficiency (η%) approached 94.87% in presence of 250ppm of the inhibitor molecules. The effect of temperature on the corrosion rate of carbon steel was studied in the temperature range from 30 to 70°C. Finally, scanning electron microscopy was used to examine the surface morphology of carbon steel samples in absence and presence of the inhibitor. [Copyright &y& Elsevier]

The present work investigated the preparation of valine of polyaspartic acid (Val-PASP) and leucine of poly aspartic acid (Leu-PASP) by using polysuccinimide. PASP compounds were used as corrosion and scale inhibitors. The prepared derivatives in this study were characterized by using Fourier transform infrared spectroscopy and nuclear magnetic resonance 1HNMR. The electrochemical behavior of the synthesized compounds was studied on carbon steel surface using potentiodynamic polarization and electrochemical impedance spectroscopy techniques. The morphology of the C-steel specimens was surveyed using scanning electron microscopy and energy dispersive analysis of X-rays investigations. Scale agglomeration inhibition was evaluated using different concentrations of the inhibitors using standard scale test method. The highest corrosion inhibition efficiency for Val-PASP and Leu-PASP reaches 86.94 and 88.62% respectively at 250 ppm concentration, while their scale inhibition efficiency reaches 92.3 and 94.1% respectively at 125 ppm concentration. [ABSTRACT FROM AUTHOR]

Ring opening reaction was used to prepare novel anionic surfactant as CaSO 4 .2H 2 O scale and mild steel (MS) corrosion inhibitor. The prepared surfactant was designed as Hexa-anionic surfactant, and named; Sodium(2Z,16Z)-8,11-bis((Z)-3-carboxylatoacryloyl)-5,14-bis(2-((4dodecylphenyl)sulfonamido)ethyl)-4,15-dioxo-5,8,11,14-tetraazaoctadeca-2,16-dienedioate. The Hexa-anionic surfactant was characterized by FTIR, and 1 HNMR. Platinum ring method was used to study surface active properties of the investigated surfactant. The anti-scale property of Hexa-anionic surfactant was evaluated according to a static test method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD) were used to examine CaSO 4 ·2H 2 O crystal morphology. The high anti-scale performance of Hexa-anionic surfactant was related to its chelating, adsorption, and dispersion abilities. The scale inhibition ( SI %) reached the maximum 100% at concentration 7 ppm. Also, the inhibition performance of the insight surfactant for MS corrosion in synthetic water was tested by electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) techniques, accompanied with surface analysis techniques. The obtained results indicated a good corrosion mitigation action of the investigated surfactant. SEM, and EDX show the formation of Hexa-anionic surfactant's adsorbed layer on the MS surface. The adsorption of Hexa-anionic surfactant at MS followed Langmuir adsorption isotherm. Quantum calculations confirmed the experimental data. [ABSTRACT FROM AUTHOR]

Herein, we prepare effective Gemini cationic surfactants (CS II , CS IV) and characterize them using FT-IR and 1HNMR spectroscopy. The adsorptive properties of CS II and CS IV at HCl/air and C-steel/HCl interfaces were examined with surface tension and electrochemical parameters, respectively. The critical micelle concentration (CMC) of the CS II and CS IV 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 CS II and CS IV , respectively. Both CS II and CS IV 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. [Display omitted] • Highly effective low-cost cationic surfactants are prepared. • CS II and CSIV chemical structures confirmed by FTIR. • MCs confirmed the higher E ads of CS IV over CS II. • CS II and CS IV are mixed type inhibitors. • CS II and CS IV are well-adsorbed at interfaces. [ABSTRACT FROM AUTHOR]