Emulsified collectors (ECs) have attracted increasing attention in coal slime flotation because of their superior dispersion characteristics and collecting performance compared with conventional hydrocarbon collectors. However, the relationship between flotation performance and the effects of ECs on microorganisms in circulating water remains poorly understood. In this study, four ECs were prepared using cationic (dodecyltrimethylammonium bromide (DTAB)), anionic (sodium dodecyl sulfate (SDS)), nonionic (Tween-80), and solid particle-based (β-cyclodextrin (CD)) emulsifiers. The droplet size distribution, flotation performance, adsorption behavior, and microbial response were systematically evaluated. The results showed that ECs significantly improved coal slime flotation compared with conventional kerosene. Among the surfactant-based ECs, smaller oil droplet sizes resulted in higher clean coal recovery, demonstrating the critical role of collector dispersion in flotation performance. Fourier transform infrared spectroscopy provided qualitative evidence of stronger relative adsorption of ECs on coal surfaces than that of conventional kerosene. Yeast survival tests revealed that all ECs exhibited less adverse impact on microorganisms than kerosene. However, for surfactant-based ECs, microbial survival decreased as flotation performance increased. A preliminary negative correlation (R2 = 0.9323, n = 4, where “n” denotes the number of collector formulations tested) was observed between the yeast survival rate and the number of oil droplets, suggesting that fine oil droplets remaining in the aqueous phase may have contributed to reduced microbial viability. In contrast, the β-CD-stabilized Pickering emulsion achieved both the highest flotation efficiency index (56.22) and the highest yeast survival rate (66.49%), outperforming Tween-80-EC (54.90 and 58.65%), SDS-EC (50.95 and 61.45%), DTAB-EC (50.08 and 63.31%), and conventional kerosene (40.32 and 53.35%). These findings demonstrate the importance of balancing flotation performance and environmental compatibility in the design of sustainable flotation collectors for coal processing.

The new cationic surfactant-based azo Schiff compound (azoS8) was prepared, characterized, and investigated as a corrosion inhibitor for carbon steel in 1 M HCl by means of electrochemical approaches in this study. The chemical structure of azoS8 has been verified by the FTIR and 1H NMR spectra. According to the electrochemical system, the examined surfactant is a mixed-type inhibitor. The surfactant azoS8 was an adequate corrosion inhibitor, as evidenced by the reduction in corrosion current densities and the rise in coverage of the surface identified with an evolving inhibitor amount. When the surfactant azoS8 had been added, the capacitive cycle loops on the Nyquist plots were broader, and the dimension of these loops expanded with surfactant azoS8 concentration. This implies that the amount of surfactant azoS8 led to an improvement in the impedance of the steel electrode. The surfactant azoS8 adsorption system is well suited to the Langmuir adsorption isotherm. It was discovered that azoS8 had a Gibbs free energy change value of -27.72 kJ mol-1, which is a mixed adsorption mechanism containing both physisorption and chemisorption.

The inhibitory mechanism of four ionic liquids (ILs) generated from imidazolium is reported in this study. The goal of the research was to see how the cation structure of ILs affected the corrosion inhibition of carbon steel in 1 M HCl. The chemical structure of ILs was verified by elements analysis, Fourier-transform-infrared (FTIR), thermo gravimetric (TGA), nuclear magnetic resonance ((HNMR)-H-1, D2O, C-13 NMR) and hetero-nuclear single-quantum correlation (HSQC). The inhibitory efficiency was measured using mass loss and electrochemical tests and varied from 62.5% to 97.2%. The Langmuir model accurately defined their adsorption on a steel substrate. Adsorption of novel ILs on steel substrates is a mixed physisorption and chemisorption method. To ensure the mechanism of adsorption of current ionic liquids, FTIR and ultraviolet (UV) spectra were employed. (C) 2022 Elsevier B.V. All rights reserved.

Copper corrosion in acidic cleaning solutions is a major worry for heat exchangers. Corrosion inhibitors derived from natural sources might be a viable option. The isolation of Oleuropein compound from olive leaf and investigation of its anticorrosion potential for copper in 1.0 M H 2 SO 4 solution are reported here. All experimental results from LC–MS, FT-IR, 1 H and 13 C-NMR characterizations support the molecular structure of Oleuropein. Electrochemical and gravimetric tests were used to evaluate the corrosion inhibition capabilities of Oleuropein. According to polarization investigation, Oleuropein is a mixed-type inhibitor. Oleuropein's inhibitory efficacy increases with concentration, attaining an optimum value (98.92%) at 100 mg L −1 . At high temperatures, Oleuropein can be considered an efficient inhibitor. Thermodynamic variables for the activation operation and copper dissolution were computed and addressed as well. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) examinations revealed that Oleuropein produced an outer layer on the copper surface, shielding it from severe acid damage. Quantum chemical simulations were employed to propose molecular explanations for Oleuropein's inhibitory actions.

CuNi (90:10) alloy is widely used in desalination plants. CuNi alloy corrosion in sulfide-containing seawater is the fundamental problem in the desalination industry. Here we have confronted this difficulty by using ammonium-based ionic liquid (Diethyl (2-methoxyethyl)-methyl ammonium Bis(fluorosulfonyl)imide) [DEMEMA][FSI]. The results revealed that the [DEMEMA][FSI] can suppress Cu–Ni alloy corrosion in a solution of (3.5% NaCl + 10 ppm sulphide) with an efficiency of 98.4% at 120 ppm. This has been estimated by electrochemistry and gravimetry. Furthermore, [DEMEMA][FSI] inhibits the growth of sulfate-reducing bacteria SRB in saline water. Surface morphology testing confirmed [DEMEMA][FSI] adsorption on Cu–Ni surface alloys. In addition, quantum calculations have been used to theoretically predict inhibition efficiency [DEMEMA][FSI].

Strong acids are commonly used in petroleum wells to remove scale layers from the surface of N80 C-steel pipe. The corrosive effects of these acids, on the other hand, pose a significant risk to C-steel pipes. For the first time, we discovered the anti-corrosion properties of cationic Gemini surfactant, 1,2-bis(dodecyldimethylammonio) ethane dibromide (DMAEB), for N80 C-steel pipe in acid washing solution (15.0% HCl). The DMAEB, in particular, can reduce the corrosion rate of N80 C-steel by approximately 97%. DMAEB molecules work as a mixed-type corrosion inhibitor, according to electrochemical results. The DMAEB demonstrated a high inhibition effect at high temperatures, as well as high activation energy against the corrosion process. DMAEB's significant performance is primarily due to physical adsorption on the N80 C-steel surface, as confirmed by adsorption isotherms, SEM, EDX, FT-IR, and theoretical studies. Our findings shed new light on the use of Gemini surfactants as corrosion inhibitors in petroleum wells.

In electrochemical energy storage systems, Li-ion batteries have drawn considerable interest. However, the corrosion of the aluminum current collector in the LiN(SO2CF3)2 electrolyte has a major effect on battery efficiency. To protect the current collector from the corrosive action of the LiN(SO2CF3)2 electrolyte, new nanocomposites based on Ni(II)tetrakis[4-(2,4-bis-(1,1-dimethyl-propyl)-phenoxy)]phthalocyanine (Ni-Pc) and polyaniline matrix (PANI) (i.e. PANI@Ni-Pc composites) are coated on the aluminum current. SEM, XRD, and EDS were used to characterize the PANI@Ni-Pc composite. This method represents a novel approach to the production of Li-ion batteries. Electrochemical tests show that the PANI@Ni-Pc composites can protect aluminum from corrosion in LiN(SO2CF3)2. The output of PANI@Ni-Pc composites is influenced by the Ni-Pc concentration. The composite PANI@Ni-Pc is a promising way forward to build high-stability Li-Ion batteries.

The liberation of hydrogen gas and corrosion of negative plate (Pb) inside lead-acid batteries are the most serious threats on the battery performance. The present study focuses on the development of a new nanocomposite coating that preserves the Pb plate properties in an acidic battery electrolyte. This composite composed of polyaniline conductive polymer, Cu-Porphyrin and carbon nanotubes (PANI/Cu-Pp/CNTs). The structure and morphology of PANI/Cu-Pp/CNTs composite are detected using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Based on the H2 gas evolution measurements and Tafels curves, the coated Pb (PANI/Cu-Pp/CNTs) has a high resistance against the liberation of hydrogen gas and corrosion. Electrochemical impedance spectroscopy (EIS) results confirm the suppression of the H2 gas evolution by using coated Pb (PANI/Cu-Pp/CNTs). The coated Pb (PANI/Cu-Pp/CNTs) increases the cycle performance of lead-acid battery compared to the Pb electrode with no composite.

Epoxy nanocomposite coatings are an essential way to protect petroleum storage tanks from corrosion. For this purpose, the new nanocomposite epoxy coatings (P-M/epoxy composites) have been successfully designed. The P-M/epoxy composites are based on the metal vanadium oxy-phosphate M0.5VOPO4 (where M=Mg, Ni, and Zn). The function of P-M/epoxy composites as anti-corrosion coatings was explored using electrochemical and mechanical tests. Using electrochemical impedance spectroscopy (EIS), it has been noticed that the pore resistance and polarization resistance of the P-M/epoxy composites remain higher as compared to the neat epoxy. The P-M/epoxy composites have the greatest impact on the cathodic dis-bonded area and water absorption. Besides, P-M/epoxy composites exhibit a very high order of mechanical properties. Further, Mg0.5VOPO4 has the greatest effect on the anti-corrosion properties of epoxy coating followed by Zn0.5VOPO4 and Ni0.5VOPO4. All these properties lead to developing effective anti-corrosion coatings. Thus, the net result from this research work is highly promising and provides a potential for future works on the anti-corrosion coating.

Corrosion of biodiesel-filled fuel tanks has become a major problem in the use of biodiesel as a new green energy source. The ionic liquid 1-Hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C10H19N2]+[C2F6NO4S2]- was used to control corrosion of C-steel in non-edible biodiesel to resolve this problem. The anti-corrosion and antioxidant properties of the [C10H19N2]+[C2F6NO4S2]- were characterized using weight loss, electrochemical impedance spectroscopy, total acid number measurements beside SEM and EDX analysis. The findings show that [C10H19N2]+[C2F6NO4S2]- plays an important role in preventing C-steel corrosion in biodiesel with an efficiency close to 99 percent. The adsorption capability and antioxidant properties of [C10H19N2]+[C2F6NO4S2]- are the major contributors to the ionic liquid's anti-corrosion properties. We anticipate that this work will help to sustainable expand the use of biodiesel as a renewable energy source.

The impact of rare earth compounds (CeCl3 and Ce2(SO4)3) on the corrosion inhibition of aluminum alloy (AA6061) in 3.5% NaCl solution was elucidated using polarization, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS) and complemented with EDX and SEM examination. The addition of either CeCl3 or Ce2(SO4)3 to the blank chloride solution, decreases the corrosion current and causes a widening of the passive potential range between corrosion potential (Ecorr) and pitting potential (Epit). The data confirmed that CeCl3 and Ce2(SO4)3 act as corrosion inhibitors. It was found that the inhibition performance of Ce2(SO4)3 are higher than that of CeCl3. In the presence of Ce2(SO4)3 and CeCl3, the AA6061 surface is well protected, in which the surface of AA6061 was smoother and the corroded areas obviously diminished. The results suggest that the existence of Ce2O3/Ce(OH)3 conversion coat on the electrode surface enhances the charge and mass barrier leading to the reduction in corrosion rates of the AA6061 alloy.

New series of ionic liquids based on benzalkonium chloride derivatives are presented in this work. The new ionic liquids are recognized by elemental analysis, Fourier transform infrared (FTIR), and hydrogen nuclear magnetic resonance (1H NMR). They have been considered as promising anti-corrosion and anti-microbial additives in the petroleum industry. In this paper, the anti-corrosion and anti-microbial activities of four synthesized benzalkonium chloride derivatives (BCIL) are measured for carbon steel structure immersed in the formation water and contaminated solution by sulfate-reducing bacteria (SRB). The anti-corrosion properties of BCIL are evaluated using chemical and electrochemical methods. The anti-microbial activities of BCIL were tested against SRB. Collectively, the results confirmed that the new ionic liquids (BCIL) play as anti-corrosion and anti-microbial additives. These new additives led to protect the carbon steel structure from corrosion caused by formation water and from bio-corrosion caused by SRB.

Corrosion is a costly and possibly unsafe issue in numerous fields. Nowadays, the using of nanocomposites coatings as an adequate approach to protect the steel from corrosion becomes a target for many researchers. The present review explores the potential use of nanocomposites coatings for corrosion control. Recent studies in the field of corrosion inhibition were reviewed here. Numerous factors influencing on the nanocomposite coatings performance such as types of nano-materials, size, concentrations, mixing, and additives were described. This review focuses on alkyd resin, epoxy resin and polyurethane composites. Additionally, we addressed the new materials in the design of nanocomposites coatings and discussed future potential approaches.

Ionic liquids with high environmental value and adsorption properties are a requirement for the new trend for corrosion inhibitors. Here, we synthesis three new ionic liquids based on dicationic imidazolium (IL1, IL2 and IL3) to produce green inhibitors for stainless steel corrosion in acidic environment. The anionic portion of all prepared ionic liquids is BF4-. New ionic liquids were recognized by means of element inspection, FT-IR, TGA and H-1 NMR spectroscopy. All prepared ionic liquids work as good corrosion inhibitors. Where their efficiencies are 91.5%, 98.4% and 83.3% for IL1, IL2 and IL3, respectively at 100 ppm. The counter portion of ILs (BF4-) has a great role in the adsorption process. (C) 2019 Elsevier B.V. All rights reserved.

The corrosion in thermal desalination units during the acidic cleaning could have negatives impacts on the economic and environmental results. Here we address these negatives impacts using sulfonium-based ionic liquid (i.e. Triethylsulfonium bis(trifluoromethylsulfonyl)imide, abbrev. TESFI). Chemical, electrochemical methods and quantum chemical calculations were used to test the efficiency of TESFI. Results obtained show the TESFI compound was effective with optimal corrosion inhibition values of 97.8% at 120 ppm. Moreover, we noted that the efficiency of TESFI decreased from 97.8% to 88.2% with elevating the temperature from 303 K to 343 K. Our results suggest that the adsorption of TESFI molecules onto the 304 SS surface plays the main step in the corrosion inhibition mechanism. Quantum chemical parameters provided a comprehensive picture of the adsorption of TESFI molecules. (C) 2019 Elsevier B.V. All rights reserved.

In this work, the aluminum-air battery performance is improved by adding nonionic surfactant (nonoxynol-9) to battery electrolyte (4.0 M NaOH). The efficiency of nonoxynol-9 is determined using hydrogen gas evolution and electrochemical measurements. The surface analysis is explored using scan electron microscope and energy dispersive X-ray spectroscopy. Battery performance is investigated at 20 mA cm(-2). The results show that the battery performance is significantly improved by adding nonoxynol-9. This is due to the low corrosion rate of aluminum in 4.0 NaOH solution resulted from physical adsorption of nonoxynol-9 on aluminum surface. The surfactant suppresses the hydrogen gas evolution and increases the anode utilization and capacity density. The maximum inhibition efficiencies of nonoxynol-9 from hydrogen gas evolution and electrochemical measurements are 85.6% and 92.8%, respectively at 2.0 mM. Nonoxynol -9 behaves as a cathodic-type inhibitor and its adsorption complies with Freundlich type isotherm. The adsorption of surfactant on the aluminum surface is emphasized by surface analysis.

Abstract In this paper, the plasma electrolytic oxidation (PEO) was used to improve the corrosion resistance of aluminum in 0.5 M HCl solution. Influence of many factors such as the composition of electrolytes, time and inorganic additives on the performance of PEO process have been investigated. The surface morphology of PEO films was inspected using SEM, EDX and XRD analysis. The electrochemical impedance spectroscopy (EIS) and polarization measurements were carried out to evaluate the corrosion resistance of aluminum. The hardness and reduced modulus of aluminum surface at different PEO process time were determined by nanoindenter measurements. The results showed that the best conditions for formation high efficient oxide layer on the aluminum surface during PEO process were carried out in 0.001 M NaOH electrolyte containing 9 × 10−5 M Na2WO4 for 5 min. The PEO process is able to inhibit uniform and pitting corrosion of aluminum in HCl solution. The surface morphology analysis showed that PEO process produce a highly resistant protective oxide layer, mainly composed of orthorhombic crystalline phase of α-Al2O3. This oxide characterized by its greater hardness.

An in-situ electrochemical polarization study was used to investigate the erosion-corrosion (E-C) behavior of C-steel in Egyptian crude oil-water mixture (ECWM) under mimetic different conditions. The anodic polarization responses for C-steel in ECWM are recognized active-passive region. Flow rate, sand particles and temperature increased the E-C rate. Disintegration rate to erosion rate proportion (E/C) was calculated and talked about.

Organic coatings have been widely used to protect carbon steel pipelines from external corrosion; however, they often suffer from permeability and weak adhesion. Here we show that synthetic lanthanide bis-phthalocyanine complexes, LnPc(2) (Ln = lanthanide metal, Pc = C32H16N8 denotes the phthalocyanine ligand) can be used to form new nanocomposite coatings to provide corrosion protection to the underlying carbon steel pipelines. Electrochemical studies (EIS and potentiodynamic polarization) showed that the incorporation of LnPc(2) compound (PrPc2, SmPc2 and HoPc2) additives with alkyd coating, leads to a significant increase in the corrosion resistance of carbon steel in 0.5 M HCl solution. The alkyd@LnPc(2) nanocomposite coatings absorb very low water volumes, when compared to the neat alkyd coating. LnPc(2) compounds allowed enhancing the pull-off adhesion of coatings performance from 3.34 MPa to 19.94 MPa. The efficiency of alkyd@HoPc2 coating appears higher than that of alkyd@PrPc2 and alkyd@SmPc2 coatings. The protective properties of alkyd@LnPc(2) coatings were confirmed by SEM, TGA, scratch hardness, impact resistance, bend test and contact angle analysis.

The corrosion created by microorganisms (SRB) is a major problem in petroleum filed. In this study, the microbial corrosion impedance of carbon steel in oilfield saline water via quaternary ammonium salt (DDAC) has been estimated utilizing weight loss, electrochemical measurements and surface morphology analysis. Quantum chemical approach was used to ascertain the correlation between the inhibitive effect and molecular structure of DDAC. It showed that SRB increased the destruction of carbon steel in oilfield saline water compared to the control. DDAC restricted the corrosion rate of carbon steel whereas increased the difficulty in producing of SRB.