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Purpose: The aim of this paper is to solve the toxic and harmful problems caused by traditional volatile corrosion inhibitor (VCI) and to analyze the effect of the layered structure on the enhancement of the volatile corrosion inhibition prevention performance of amino acids. Design/methodology/approach: The carbon dots-montmorillonite (DMT) hybrid material is prepared via hydrothermal process. The effect of the DMT-modified alanine as VCI for mild steel is investigated by volatile inhibition sieve test, volatile corrosion inhibition ability test, electrochemical measurement and surface analysis technology. It demonstrates that the DMT hybrid materials can improve the ability of alanine to protect mild steel against atmospheric corrosion effectively. The presence of carbon dots enlarges the interlamellar spacing of montmorillonite and allows better dispersion of alanine. The DMT-modified alanine has higher volatilization ability and an excellent corrosion inhibition of 85.3% for mild steel. Findings: The DMT hybrid material provides a good template for the distribution of VCI, which can effectively improve the vapor-phase antirust property of VCI. Research limitations/implications: The increased volatilization rate also means increased VCI consumption and higher costs. Practical implications: Provides a new way of thinking to replace the traditional toxic and harmful VCI. Originality/value: For the first time, amino acids are combined with nano laminar structures, which are used to solve the problem of difficult volatilization of amino acids. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to investigate the activity of 4-((4-((2-hydroxyethyl)(methyl)amino)benzylidene) amino)-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one (HEMAP), a Schiff base synthesized and characterized for the first time, to the authors' knowledge, as a novel inhibitor against corrosion of mild steel (MS) in hydrochloric acid solution. Design/methodology/approach: HEMAP was characterized by some spectroscopic methods including High-Resolution Mass Spectrometry (HRMS), Proton Nuclear Magnetic Resonance (1H NMR), Carbon-13 (C13) nuclear magnetic resonance (13C NMR) and Fourier Transform Infrared Spectroscopy (FT-IR). Then, the inhibition efficiency of HEMAP on MS in a hydrochloric acid solution was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). To explain the inhibition mechanism, the surface charge, adsorption isotherms and thermodynamic parameters of MS in the inhibitor solution were studied. Findings: EIS tests displayed that the highest inhibition efficiency was calculated approximately as 99.5% for 5 × 10−2 M HEMAP in 1 M HCl solution. The adsorption of HEMAP on the MS surface was found to be compatible with the Langmuir model isotherm. The thermodynamic parameter results showed that the standard free energy of adsorption of HEMAP on the MS surface was found to be more chemical than physical. Originality/value: This study is important in terms of demonstrating the performance of the first synthesized HEMAP molecule as an inhibitor against the corrosion of MS in acidic media. EIS tests displayed that the highest inhibition efficiency was calculated approximately as 99.5% for 5 × 10−2 M HEMAP in 1 M HCl solution. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to prepare new modified alkyd resins and use it as an antimicrobial binder for surface coating applications. Design/methodology/approach: Various modified alkyd resins were prepared by partial replacement of 3,6-dichloro benzo[b]thiophene-2-carbonyl bis-(2-hydroxy ethyl)-amide as a source of polyol with glycerol and confirmed by acid value, FT-IR, 1H-NMR. The modified alkyd resins were covering a wide range of oil lengths and hydroxyl content (0%, 10%, 20% and 30% excess-OH). The antimicrobial activity of the prepared alkyds was also investigated. The coatings of 60 ± 5 µm thickness were applied to the surface of glass panels and mild steel strips by means of a brush. Physico-mechanical tests, chemical resistance and antimicrobial activities were investigated. Findings: The obtained results illustrate that the introduction of benzo[b]thiophene derivative as a modifier polyol within the resin structure improved the film performance and enhanced the physico-mechanical characteristics, chemical resistance and the antimicrobial activities. Practical implications: The modified alkyd resins can be employed as antimicrobial binders in paint compositions for a variety of surfaces, particularly those that are susceptible to a high number of bacteria. Originality/value: Modified alkyd resins based on antimicrobial heterocyclic compounds have the potential to be promising in the manufacturing of antimicrobial coatings and development of paints, allowing them to function to prevent the spread of microbial infection, which is exactly what the world requires at this time. Also, they can be applied in different substrates for industrial applications. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to prevent mild steel (MS) against corrosion in 0.5 M HCl solution, 2-amino-4-methoxy-6-methyl-1,3,5-triazine was used. The effectiveness of the compound as a corrosion inhibitor was studied via electrochemical, surface and theoretical calculation techniques. Design/methodology/approach: For concentrations ranging from 0.5 to 10.0 mM, almost similar polarization resistances were obtained from electrochemical impedance spectroscopy (EIS) and linear polarization resistance tests. It also investigated inhibitive activity of 2-amino-4-methoxy-6-methyl-1,3,5-triazine on the steel surface using scanning electron and atomic force microscope instruments. Langmuir adsorption is the best matched isotherm for the adsorption of the inhibitor to the steel surface. Findings: EIS method was used to determine inhibition efficiency, which was determined to be 95.7% for 10.0 mM inhibitor containing acid solution. Density functional theory's predictions for quantum chemistry agreed well with the other experimental results. Originality/value: The methods used in this study are effective and applicable; the used organic inhibitor is 2-amino-4-methoxy-6-methyl-1,3,5-triazine; and protective effectiveness is important, which is crucial for the task of MS corrosion prevention. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to investigate the eco-friendly neodymium tartrate (NdTar) inhibitor for mild steel in sodium chloride (NaCl) solution. Design/methodology/approach: The mild steel 1010 coupon was considered for the current study. Weight loss and the electrochemical methods were used to evaluate the inhibitory effects of neodymium chloride (NdCl3) and NdTar on mild steel in NaCl solution. Scanning electron microscopy, energy-dispersive X-ray analysis and attenuated total reflectance-Fourier transform infrared spectroscopy measurements were carried out to study the morphology and composition of the film, nature of deposits and corrosion products formed in test media on the corroded steel, with the objective of further analyzing the observed behavior of the two inhibitors. Findings: Of the two, NdTar performs better than NdCl3 because it shields mild steel surfaces for longer. According to the results, when NdCl3 is present in a corrosive solution, the protective film only comprises Nd/Fe oxide/hydroxide/carbonate. However, when neodymium is coupled with the tartrate group (an organic group) and then added to the NaCl solution, the inhibitor film comprises both bimetallic complexes (Fe-Tar-Nd) and metal oxide/hydroxide/carbonate, which results in a more compact film and has higher inhibition efficiency. Originality/value: This study evaluated the combined effects of inorganic and organic inhibitors with those of an inorganic inhibitor used alone for mild steel in NaCl solution. [ABSTRACT FROM AUTHOR]

Purpose: This study aims is to evaluate the environmentally friendly turmeric as a corrosion inhibitor for mild steel in a simulated seawater corrosion medium such as a 3.5% NaCl solution. To accomplish this, different proportions of turmeric (0.3, 0.6, 0.9 and 1.5%) were added to solvent-free epoxy-acrylate resin-based coating formulations. Then, all the formulations were sonicated and coated as thin films on different substrates; these coated films were then polymerized under a dose of 10 kGy of electron beam (EB) radiation. Design/methodology/approach: Various properties of all cured coating films such as Fourier transform infrared spectroscopy, water contact angle, thermogravimetric analysis and scanning electron microscopy were studied, in addition to their physical, chemical and mechanical properties. Turmeric was then evaluated in these formulations as an anticorrosion agent for mild steel in 3.5% NaCl. The different corrosion-resistant properties of all EB-cured coating films were evaluated by open circuit potential measurements, rust degree, blistering, adhesion loss at X-cut and weight loss measurements. Findings: The results showed that most of the formulations are homogeneous, especially at low concentrations of turmeric, and their films have high-performance properties. Originality/value: It was also found that the formulation containing 0.6% of turmeric per 100 g of coating was considered the best formulation as it gave the highest protection to the mild steel plates with no negative effects on the chemical and physical properties of their films. [ABSTRACT FROM AUTHOR]

Purpose: Here, diazo coupling reaction was imparted on chemically inert lignin isolated from natural resources. Activated lignin was coupled with the diazotised aniline, m-nitroaniline, p-nitroaniline-, and p-anisidine gives organic pigments. Design/methodology/approach: The continuous increase in particle size of pigments confirms addition of diazotised salt to lignin by coupling reaction. Further, the dispersing ability of these coloured pigments were exploited in polymer matrix. Epoxy-polyamine cross linking system was doped with difference percentage of pigments and coated on mild steel metal surface. The morphology of these composites was understood by SEM, particle size, differential scanning calorimeter and thermo gravimetric analysis. Findings: The synthesised organic pigments were characterised by FT-IR, 1H NMR and UV-visible spectroscopy. It was observed that hiding power of aniline- and m-nitroaniline–based azo pigments was more than p-nitroaniline- and p-anisidine–based azo pigments. Thermal properties as well as water contact angles of coatings were improved with pigment concentration. The chemical resistivity of coating was observed to be improved with the increasing % of lignin-based azo pigment. Originality/value: Lignin-based azo pigment has great potential to replace metal oxide pigment and provide strategy for utilisation of lingo-cellulosic biowaste material. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to study the corrosion behavior of Q235 steel in the bentonite-based resistance-reducing agent (RRA) with different infiltration rates of underground water. Design/methodology/approach: The corrosion behavior of the steel in underground water was assessed by weight loss experiment, electrochemical impedance spectroscopy and polarization curve. Findings: The results showed that the corrosion rate of the steel in the RRA pastes was much lower than that in the original acidic soil. The underground water infiltration slightly accelerated the corrosion rate of the steel in the RRA pastes, but the acceleration role is weak. The bentonite-based RRA can be compatibly applied in the acidic soil. Originality/value: The bentonite-based RRA can significantly reduce the corrosion rate of the steel and is suitable to compatibly apply in the acidic soil. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to study the adsorption properties of a proven traditional medicine of West Africa origin, Alstonia boonei with an attempt to evaluate its application in the corrosion protection of mild steel in 5 M H2SO4 and 5 M HCl. Design/methodology/approach: Phytochemical screening and Fourier transform infrared spectroscopy analysis were used to characterize the methanolic extract of the plant. Gravimetry, gasometry and electrochemical techniques were used in the corrosion inhibition studies of the extract and computational studies were used to describe the electronic and adsorption properties of eugenol, the most abundant phytochemical in Alstonia boonei. Findings: The extract acted as a mixed-type inhibitor in both acidic solutions, with improved inhibition efficiency achieved with increasing concentration. While the efficiency increased with temperature for the HCl system, it decreased for the H2SO4 system. The mechanism of adsorption proposed for Alstonia boonei was chemisorption in the HCl system and physisorption in the H2SO4 system, and the adsorptions obeyed Langmuir isotherm at low temperatures. Computational parameters showed that eugenol, being a representative of Alstonia boonei, possesses excellent adsorption properties and has the potential to compete with other established plant-based corrosion inhibitors. Research limitations/implications: As opposed to pure compounds with distinctive corrosion effects, plant extracts are generally composed of a myriad of phytoconstituents that competitively promote or inhibit the corrosion process and their net effect is evident as inhibition efficiencies. This is, therefore, the main research limitation associated with the corrosion inhibition study of Alstonia boonei. Originality/value: Being very rich in antioxidant properties by its proven curative and preventive effects for diseases, the interest was stimulated towards the attractive results that abound from its corrosion protection of metals via its anti-oxidation route. [ABSTRACT FROM AUTHOR]

Purpose: Rotary friction welding (RFW) was used to solve the issues in fusion welding of rod to plate joints of low carbon steel (AISI 1020 steel/AISI 1018 steel) such solidification cracking, wider heat affected zone (HAZ), lower HAZ hardness, high residual stresses and distortion. The main objective of this investigation is to develop parametric mathematic models (PMMs), 3D response surface analysis to predict tensile strength (TS) and weld interface hardness (WIH) of rod to plate joints and correlate microstructure with TS and WIH of rod to plate joints. Design/methodology/approach: The three-factor x five-level central composite design (CCD) consisting fewer experiments was employed for designing experimental matrix. The tensile and microhardness tests were performed to evaluate mechanical performance of joints. The PMMs of TS and WIH of rod to plate joints were developed using polynomial regression equations incorporating the RFW parameters. The 3D response surfaces were developed using response surface methodology (RSM) to optimize RFW parameters for joining AISI 1020/AISI 1018 rod to plate. Findings: The joints made using friction pressure/friction time (FRNP/FRNT) of 3.71 MPa/s, forging pressure/forging time (FRGP/FRGT) of 3.71 MPa/s and rotational speed (RTSP) of 19.99 rps exhibited higher TS and WIH of 452 MPa and 252 HV0.5. The PMMs accurately predicted TS and WIH of rod to plate joints at less than 1.5% error and 95% confidence. The RTSP revealed greater effect on TS and WIH of rod to plate joints followed by FRGP/FRGT and FRNP/FRNT. The superior TS and WIH of joints developed using optimized process parameters is correlated to the evolution of finer bainitic microstructure in weld interface due to the dynamic recrystallization of grains ensued by optimum frictional heating and plastic deformation. Originality/value: The PMMs were developed for predicting TS and WIH of joints. The RFW parameters were optimized to enhance TS and WIH of joints. Low carbon steel rod to plates joints were developed using RFW for automotive applications without fusion welding defects. The microstructural features of low strength and high strength rod to plate joints were correlated to the TS and WIH of rod to plate joints. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to enhance to corrosion protection of NiZn-plated steel by electroplating multilayer coating. Design/methodology/approach: The multilayer coating consists of three layers on mild steel substrate, such as Cr3+ chromate conversion layer (CCC), electrodeposited nanosilica zinc-nickel composite layer (ZnNiSi) and electrodeposited zinc-nickel alloy layer (ZnNi). Its morphology, composition and corrosion behaviour were investigated by various methods. Findings: Polarization curves indicated that polarization resistance and corrosion current density of CCC/ZnNiSi/ZnNi/Fe (6.956 kO.cm2; 2.56 µA.cm−2) were two times higher and five times lower than that of ZnNiSi/ZnNi/Fe (3.42 kO.cm2; 12.52 µA.cm−2), respectively. From electrochemical impedance spectroscopy data, charge transfer resistances were 1.344, 2.550 and 2.312 kO.cm2 for ZnNi, ZnNiSi/ZnNi and CCC/ZnNiSi/ZnNi, respectively. Salt spray test indicated that after 48 h, surface of ZnNi and ZnNiSi was covered by white rust, whereas no white rust was observed on surface of CCC/ZnNiSi/ZnNi. After 600 h, there were red rust spots (1% surface coverage) on surface of Zn-Ni, whereas only white rust was observed on both ZnNiSi/ZnNi (100% surface coverage) and CCC/ZnNiSi/ZnNi (10% surface coverage). Originality/value: Multilayer coating enhanced significantly the corrosion protection for steel, as compared to the single-layer coating. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to confirm the importance of using metal–organic frameworks (MOFs) in the field of corrosion control due to their potential use as corrosion inhibitors. Design/methodology/approach: NH2–MIL–101(Cr), an amine-functionalized chromium-based MOF [Cr(III)-MOF], was prepared by solvothermal technique. Thereafter, Cr-MOF was used as an anticorrosion additive for mild steel (MS) in 1 m HCl solution. This inhibition behavior was tested by electrochemical tests including electrochemical impedance spectroscopy and potentiodynamic polarization (PDP). Findings: Increasing the added amount of Cr-MOF enhances its inhibition performance, which attained 96.40% at 30 ppm. The obtained data from PDP measurements describe Cr-MOF as a mixed-type inhibitor. Based on SEM/EDS and FTIR analysis, the adsorption of Cr-MOF on the surface of MS that prevents MS corrosion has been demonstrated. Furthermore, Langmuir model is the most adequate adsorption isotherm for the obtained experimental data. Originality/value: This study revealed that NH2–MIL–101(Cr), an amine-functionalized chromium-based MOF (Cr(III)-MOF), is a potential corrosion inhibitor for MS in 1 m HCl solution. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to investigate the presence of silicon dioxide (SiO2) nanoparticles in o-toluidine monomer as a reactant and ammonium persulfate as an oxidant to obtain the poly(o-toluidine) (POT)/SiO2 nanocomposites by oxidative polymerization method. Design/methodology/approach: Fourier transformation infrared spectroscopy, X-ray diffraction and field emission scanning electron microscopy were used to characterize the structural properties of the composite. POT/SiO2 nanocomposites were mixed with acrylic resin through a solution mixing method and the composites were coated onto the surface of mild steel. Electrochemical measurements were used to determine the corrosion protection efficiency (P.E.%) of polymer composite coatings using 3.5% NaCl solution as corrosion environment. Findings: The results obtained reveals that the POT/SiO2/acrylic resin composite coatings have got higher corrosion P.E.% than that of POT/acrylic resin coatings. Originality/value: The formation of uniformly passive layer in the POT/SiO2 composite was used to enhance the P.E.% on mild steel surface. The POT/SiO2/acrylic resin nanocomposites showed effective anticorrosive behavior on mild steel in 3.5% NaCl solution. [ABSTRACT FROM AUTHOR]

Purpose: Surface pretreatment of iron and its alloys to remove stains and inorganic contaminants on the metal surface undergoes dissolution by virtue of the strong acidic media thereby increasing its susceptibility to corrosion. The purpose of this study is to explore the corrosion mitigation prospects of green corrosion inhibitors on mild steel surface. Design/methodology/approach: Corrosion inhibition performance of Garcinia gummi-gutta leaf extract (GGLE) was explored against mild steel in 1 M HCl solution using the weight-loss method, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques. Surface characterization was carried out to study the mechanism of inhibitor action. Findings: The concentration of GGLE varied from 100 to 6,000 ppm and the result indicates that corrosion inhibition efficiency was amplified by raising the inhibitor concentration. The maximum inhibition efficiency was 82.2% at 6,000 ppm concentration. EIS results show the development of a protective layer of inhibitor molecule over the metal surface and PDP demonstrates that the inhibitor operates as a mixed-type inhibitor. Scanning electron microscopy and atomic force microscopy were executed to assess the surface morphology and roughness, respectively. Originality/value: To the best of the authors' knowledge, so far, no studies have been reported on the corrosion inhibition performance of GGLE which is rich in many bioactive components especially hydroxyl citric acid. This work encompasses the corrosion inhibition capability of GGLE against mild steel in an acidic medium. [ABSTRACT FROM AUTHOR]

Purpose: Aiming at the characteristics of large stiffness, low ductility, and poor energy dissipation capacity of cross-laminated timber (CLT) shear wall, a method of opening vertical joints and adding low-yield dampers in CLT shear wall is proposed to improve its energy dissipation capacity and ductility. Design/methodology/approach: The finite element model of CLT shear walls with low-yield dampers and dampers assembly was established by ABAQUS. The structural shape of low-yield dampers that meet the requirements of vertical joints in CLT shear walls is studied by numerical analysis. The influence of the number and position of low-yield dampers on the energy dissipation of the shear wall system is studied. Findings: The results show that the low-yield damper with diamond openings should be used in the CLT shear wall, and the energy dissipation effect is the best when the CLT shear wall is uniformly covered with low-yield dampers. After the uniform arrangement of four groups of low-yield steel dampers, the energy consumption of the CLT shear wall increases by 75.38%, and the ductility increases by 13.22%. Originality/value: There are few studies on replacing connectors between shear walls with low-yield steel dampers, and rectangular soft steel dampers are prone to stress concentration and poor deformation capacity. Therefore, this paper establishes the model of perforated low-yield damper and CLT and makes numerical analysis to determine the opening form, geometric parameters of low-yield damper, and the optimal layout scheme in CLT shear wall. [ABSTRACT FROM AUTHOR]

Purpose: Plant development and use as green corrosion inhibitors are already recognized as one of the most environmentally friendly and effective protocols. In recent years, efforts have been made to find green corrosion inhibitors as an alternative to synthetic inhibitors for metals in acid medium. This paper aims to report the investigation of use of aqueous extracts of Tamarindus Indica as green inhibitors for corrosion of metals within different circumstances. Design/methodology/approach: The use of Tamarindus Indica extracts (leaves, stem, fruit pulp and fruit husk) as corrosion inhibitors for mild steel and aluminum in different mediums (HCl, H2SO4, formic acid and citric acid) at different temperatures was investigated. Findings: The inhibitory efficiency of Tamarindus Indica extracts increases with increasing concentration and decreases with increasing temperature. Langmuir is the adsorption isotherm, and the extract (inhibitor) is a mixed-type inhibitor (physisorption and chemisorption). Practical implications: Tamarindus extracts (leaves, stem, fruit pulp and fruit husk) are effective inhibitors and can be used to protect metals from corrosion at different circumstances. Originality/value: To the best of the authors' knowledge, this is the first review that discusses the use of Tamarindus Indica extracts as corrosion inhibitors for metals. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to develop the bio-composite organic coatings by adding the bio-based additives that are extracted from banana peels and henna leaves as the organic corrosion inhibitors. Design/methodology/approach: Bioactive constituents with inhibition properties are extracted from banana peels and henna leaves by using ethanol to form the ethanolic extract. The inhibiting efficiency of these bioactive constituents on mild steel corrosion in 3.5% sodium hydroxide (NaCl) solution is investigated. The investigation is performed using electrochemical impedance studies for 30 days. The optical and adhesive properties of the bio-composite coating systems have also been studied. Findings: The best protection is obtained as the loading ratio of the banana peels ethanolic extract (BPEE) and henna leaves ethanolic extract (HLEE) are 10 Wt.% and 30 Wt.%, respectively. Overall, the results obtained show that the BPEE and HLEE not only enhance the optical properties but also can serve as an effective inhibitor for corrosion without affecting the adhesiveness of the neat acrylic properties. Originality/value: Banana peels and henna leaves consist of bioactive constituents that have anti-corrosion properties which could inhibit corrosion. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to investigate influence of extraction solvent on the efficacy of apricot pomace extract (APE) as a sustainable corrosion inhibitor for mild steel in sodium chloride solution. Design/methodology/approach: The chemical profiles of the extracts were analyzed using gas chromatography–mass spectrometry. Total phenolic, total flavonoid content and antioxidant properties of the extracts were determined. Besides, gravimetric, potentiodynamic polarization and atomic force microscopy were used to study the corrosion inhibition. The effect of immersion period on inhibition efficiency was evaluated. The reaction mechanism of the inhibitor was also discussed. Findings: Corrosion inhibition decreasing is in the following order: solution of 2-propanol/ethanol apricot pomace (E/PAPE) extract > ethanol (EAPE) > 2-propanol (PAPE). The gravimetric, polarization measurements and surface analysis revealed that the growth of inhibitory properties is prolonged, and corrosion rate reduction after 40–48 h of exposure was studied. Practical implications: APEs play an important role in the corrosion inhibition of mild steel in sodium chloride solution. Moreover, its application is potentially possible in industries. Social implications: The results contribute to the integrated valorization of food waste. Originality/value: The different compositions of the conversion/oxidation products of organic substances in solution were studied. The formation of polymerized flavanol-aldehyde adducts and oxidized quinone compounds or tautomers structures because of extract transformation in water causes main corrosion reduction in 40–48 h. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to prepare copper oxide nanoparticles (CuO NPs) in an easy and efficient way using a natural and environmentally friendly substance like ascorbic acid. Various concentrations of these nanoparticles were then added to solvent-free coating formulations to produce highly hydrophobic, corrosion-resistant and antimicrobial hybrid coatings. These hybrid formulations were also used to coat the spent fuel casks for their integrity. Design/methodology/approach: The hybrid coated films were then characterized by X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), water contact angle and Scanning electron microscope (SEM). In addition, different measurements, namely, mechanical, physical, chemical, thermal, corrosion tests, open circuit potential and antimicrobial activity of these hybrid films were performed. Findings: The results showed that the copper oxide was prepared at nanometer scales with good homogeneity and diffusion in the epoxy acrylate matrix. It also showed that some hybrid coatings have high corrosion resistance, strong hardness, excellent water resistance, remarkable antimicrobial activity and high thermal stability compared to virgin epoxy acrylates. Originality/value: The formula containing 0.5% CuO NPs was found to provide the highest corrosion protection and antimicrobial activity for mild steel in 3.5% sodium chloride (NaCl). [ABSTRACT FROM AUTHOR]

Purpose: N-containing heterocyclic benzotriazole derivatives as new corrosion inhibitor for mild steel contained in emulsion were synthesized, and their inhibition behaviors for mild steel (MS) contained in emulsion were investigated by experiments and theoretical calculations, and this study aims to prove that two new inhibitors have excellent inhibition efficiency for steel corrosion. Design/methodology/approach: 2-(1H-benzo[d][1,2,3]triazol-1-yl)-N,N-dioctylacetamide (BTN) and O-(3-(1H-benzo[d] [1,2,3]triazol-1-yl)propyl) S-(2-(dioctylamino)-2-oxoethyl) carbonodithioate (BTSC) as a new corrosion inhibitor were synthesized, and their inhibition behaviors for MS contained in emulsion were investigated by gravimetric experiment, electrochemical tests and theoretical calculations. Findings: Results of gravimetric experiment, electrochemical tests show that BTSC exhibit excellent inhibition performance, and it has a higher inhibition efficiency of 96.6% than that BTN. The resultant adsorption films from BTN/BTSC adsorbed on MS, effectively inhibiting the corrosion of MS is mainly through chemisorption and follow to Langmuir's adsorption isotherm. Originality/value: Experimental and theoretical calculations display that two new synthesized inhibitors are excellent corrosion inhibitor for MS contained in emulsion. Electrons of inhibitors mainly focus on the C, N, S and O atoms, which demonstrate these atoms are the centers of negative charge, and they supply electrons to Fe atoms through coordination bonds. [ABSTRACT FROM AUTHOR]

Purpose: Poly(ethylene terephthalate) (PET) waste from soft drink bottles was incorporated into palm olein alkyd to produce new polyol for use in polyurethane resins as surface protection on metal surfaces. Design/methodology/approach: Alkyd was prepared from palm olein, glycerol and phthalic anhydride. PET underwent simultaneous glycolysis and transesterification reactions with the alkyd. Varying the amount of PET has led to polyols with different viscosities. Polyurethane resins were produced by reacting the polyols with toluene diisocyanate. The resins were coated on mild steel panels and cured. Performances of the cured films were tested. Findings: The polyurethanes (PU) resin cured to a harder film with better thermal stability. Films showed excellent adhesion properties, while higher content of PET exhibited higher pencil hardness, better water, salt, acid and alkali resistance. Research limitations/implications: Other vegetable oils could also be used. The alkyd structure could be changed by formulation to have different functionality and the ability to incorporate higher amount of PET waste. Rate of glycolysis of PET could be increased by higher amount of ethylene glycol. Practical implications: This method has managed to use waste PET in producing new polyol and PU resins. The cured films exhibit good mechanical and chemical properties, as well as excellent adhesion and thermal stability. Social implications: The non-biodegradable PET has created environmental pollution problems connected to littering and illegal landfilling. It has become necessary to pay greater attention to recycling PET bottles for obtaining valuable products. Originality/value: This approach is different from the earlier reports, where PET was recycled to recover the raw materials. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to minimize corrosion-related pollution in the environment. From the lemongrass extract (LGE), the authors selected one of the best green inhibitors. Design/methodology/approach: The corrosion and inhibition of mild steel in traditional acidification solutions were estimated by electrochemical measurements. The corrosion appearance was observed with scanning electron microscopy, atomic force microscopy micrographs and attenuated total reflectance infrared spectroscopy spectrum. The correlation was formed between the gained inhibition efficiency (IE)% from electrochemical measurements and certain quantum chemical parameters. Findings: The results displayed that the IE was up to 90% when the LGE concentration was 300 ppm. The results confirmed that the theoretical experiments are very similar to the experimental observations. Originality/value: For the first time, LGE was used as a cheap and safe corrosion inhibitor for mild steel corrosion in the acidification process. The mechanism of mild steel corrosion and anti-corrosion in acid solution has been suggested. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to use polybenzoxazine (Pbz) functionalized ZrO2 nanoparticles to synthesize polyurethane (PU)-PbZ/ZrO2 nanocomposite. The results derived from the electrochemical impedance spectroscopy (EIS) and polarization studies indicated the superior anticorrosive activity of PU-Pbz/ZrO2 nanocomposite coatings compared to those of plain PU coatings. The decreased corrosion current was detected on the scratch of the PU-Pbz/ZrO2 nanocomposite-coated mild steel surface by scanning electrochemical microscopy (SECM) compared to other studied coatings. The superior anticorrosive and mechanical properties of the proposed nanocomposite coatings provide a new horizon in the development of high-performance anticorrosive coatings for various industries. Design/methodology/approach: The Pbz functionalized ZrO2 nanoparticles were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and thermogravimetric analysis (TGA) in terms of the structural, morphological and thermal properties of these coatings. A different formulation of coatings such as PU, PU-Pbz, PU-ZrO2 and PU-Pbz/ZrO2 were prepared and investigated for their corrosion protection performance on mild steel in natural seawater by electrochemical techniques. The surface morphological studies were done by SEM/EDX and XRD analysis. Findings: The superior anticorrosive property of the proposed nanocomposite coatings provides a new horizon in the development of high-performance anticorrosive coatings for various industries. Addition of Pbz wrapped ZrO2 nanoparticles into the PU coating resulted in the blockage of charge transfer at the metal/electrolyte interface, which reduced the dissolution of mild steel. It was revealed from the SEM/EDX analysis that the formation of the corrosion products at the metal/electrolyte interface behaved as the passive layer which reduced the dissolution of steel. Originality/value: The inclusion of polybenzoxazine functionalized ZrO2 nanoparticles to the polyurethane coating reinforces the barrier and mechanical properties of PU-Pbz/ZrO2 nanocomposite, which is due to the synergistic effect of ZrO2 and Pbz. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to explore the transformation process and transformation mechanism of carbon steel under the marine environment. Design/methodology/approach: In this paper, the transformation and rust layers corrosion products on 0Cu2Cr carbon steel with different cycles coupon test was investigated and deeply explored by scanning electron microscope, energy dispersive spectrometer, X-ray diffraction. Findings: The results showed that the thickness of rust layers grew from 71.83 µm to 533.7 µm with increasing duration of corrosion. The initial corrosion product was γ-FeOOH, then part of the γ-FeOOH continued growing, and under the capillary action, the other part of the γ-FeOOH transformed to α-FeOOH. Originality/value: To the best of the authors' knowledge, this paper puts forward for the first time a new viewpoint of the development of corrosion products of low-carbon steel in two ways. This discovery provides a new idea for the future development of steel for marine engineering. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate cimetidine as corrosion inhibitor of aluminium in hydrochloric acid medium. Design/methodology/approach: Cimetidine was characterized by gas chromatography mass spectrophotometer and Fourier transform infrared spectroscopy to determine its chemical composition and functional groups, respectively. Gravimetric, potentiodynamic polarization and electrochemical impedance spectroscopic techniques were used in the corrosion inhibition process. Thermodynamic and adsorption parameters were evaluated. And response surface methodology was used to optimize the corrosion inhibition process. Findings: Analysis of the results revealed that major constituents of cimetidine include metronidazole, n-hexadecanoic acid cyclohexane and methyl ester. It has C-H stretch, C = N stretch, CH3C-H bend, ring C = C stretch, -C-O-O stretch, N-H bend, C-O stretch and C-H bend as predominant functional groups. Adsorption of molecules of the inhibitor on the aluminium surface was spontaneous, and it followed mechanism of physical adsorption. Response surface methodology revealed that quadratic model adequately described the inhibition efficiency of cimetidine as function of inhibitor concentration, temperature and time. Chemical and electrochemical results are in agreement that the cimetidine is a viable corrosion inhibitor. Cimetidine was revealed as mixed-type inhibitor because it controlled both cathodic and anodic reactions. Originality/value: Empirical and optimization studies of cimetidine drug as corrosion inhibitor of aluminium in hydrochloric acid medium were carried out. The research results can provide the basis for deploying drugs (with mucosal protective and antacid properties) for corrosion control of metallic structures. [ABSTRACT FROM AUTHOR]

Purpose: A mixed metal oxide-based spinel ceramic pigment has been successfully synthesized incorporating inorganic, high-temperature stable furnace cement as an inbuilt binder. Step by step synthesis was done for the spinel and cement mix formulations. Design/methodology/approach: The pigment mix was synthesized by a solid-solid method where the inorganic binder was incorporated in the mix. The results suggested that CoCuMn-based spinel ceramic pigment with cement mix could be obtained at an annealing temperature of 1,100ºC for 1 h and the size, morphology and crystallinity of spinel mix were greatly influenced by the calcination temperature. Findings: The pigment mix synthesized was applied as a coating to different substrates such as aluminum, glass and Mild steel. The results revealed that spectral selectivity of TSSS paint coatings based on the CoMnCu spinel ceramic mix was much better than that of solvent-based coatings for high-temperature applications. The presence of cement as an inorganic binder makes the functioning and application of paint easy as it becomes that of a waterborne type. Originality/value: Ease of application, stability at high temperatures, best absorptivity at the solar selective spectrum and excellent adhesion properties for the selected surface are the key features of the designed pigment system. The applied pigment mix was studied as a coating to get the results for solar selective system. [ABSTRACT FROM AUTHOR]

Purpose: The composition and corrosion behaviors of recycled and virgin Pb anode were investigated in industrial zinc electrowinning solution with different methods. The purpose of this study is the illustration of good anticorrosion activity of virgin Pb anodes compared to recycled one in industrial operation, while the compositions of both of them are the same which obtained from quantmetry method. Design/methodology/approach: Its corrosion properties and electrocatalytic activity toward oxygen evolution reaction were appraised using potentiodynamic polarization, electrochemical impedance spectroscopy, galvanostatic polarization and ionic equilibrium methods. In addition, composition of anodes investigated with X-ray photoelectron spectroscopy (XPS) method. The surface composition of samples was studied via X-ray diffractogram (XRD). Findings: The results indicate that the anodes display different anodic behaviors during the galvanostatic polarization. Virgin Pb anode shows a "potential reduction" about 320 mV lower than recycled Pb anode after 6 h of polarization; also, the stable potential after 72 h for virgin Pb anode is 100 mV lower than recycled Pb anode. Also, The XPS results show a trace amount of Cl in recycled anodes which cause the more corrosion activity. XRD results indicate that virgin Pb anodes have been covered by more oxides than recycled anodes after 72 h of electrowinning. Originality/value: The treatment of corrosion behavior by virginity has not been detected by any researchers yet. Therefore, it is imperative to study the corrosion behavior and exact composition analysis of virgin and recycled Pb anodes to comprehension of them. This paper fulfills this need. [ABSTRACT FROM AUTHOR]

Purpose: Surface texturing can improve the tribological performance of contacting sliding surfaces under different contact and lubrication conditions, which has been proved both numerically and experimentally. This study aims to suggest a new methodology to evaluate the tribological behavior of textured surfaces using an adapted pendular scratch tester. Design/methodology/approach: A Charpy-type tester was adapted to meet conditions that are relevant for sliding surfaces. The test rig was used to evaluate low carbon steel textured surfaces produced via maskless electrochemical texturing. The textures were composed of 100 pockets with an average diameter of 200 µm of and variable average depths (1.5, 3.5 and 7 µm). The tests were performed under dry and lubricated conditions for smooth and textured surfaces. The lubricated tests simulated a starved condition by applying a drop of lubricant. Findings: For starved lubrication, surface texturing reduced the sliding energy when compared with smooth surfaces. This was attributed to the pocket's ability to provide an additional supply of lubricant, as well as a reduced amount of plastic deformation around the pockets during sliding of the indenter. However, under dry sliding conditions, no significant effect of surface texturing was detected. Originality/value: A new evaluation methodology was proposed, using single-pass pendular sliding of a spherical indenter to measures the energy absorbed during sliding, which was referred to as sliding energy. The measurements are repeatable and can detect sliding energy differences between smooth and textured surfaces. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to investigate the corrosion inhibition efficiency of Landolphia heudelotii (LH) on mild steel in 1 M HCl and 0.5 M H2SO4 using weight loss and potentiodynamic polarization techniques. Design/methodology/approach: Water extract of LH was used as corrosion inhibitor on mild steel in acidic media at room temperature and elevated temperatures (30-60°C). Various concentrations of the plant extract were prepared from the stock solution obtained after solvent extraction. The inhibition efficiency of LH extract was evaluated and mechanism of adsorption was deduced. Findings: LH extract showed significant corrosion inhibition on mild steel in both acidic media, with inhibition efficiency increasing with extract concentration. Potentiodynamic polarization measurements revealed mixed inhibition mechanism. Optimum inhibition efficiency was recorded at 2500 mg/L after 288 h. Mechanism of adsorption was mainly of physisorption. The inhibitor exhibited good inhibition efficiency even at elevated temperature. Research limitations/implications: This study provides new data on the anticorrosion characteristics of LH extract under the specified conditions. Further studies could expand the experimental variables and use advanced surface probe techniques. Practical implications: The developed inhibitor provides an alternative method of inhibiting corrosion on mild steel using eco-friendly materials from natural products which are less toxic, safer, cost-effective and readily available. Originality/value: The method used was effective and the inhibitor developed can be incorporated in surface coatings where mild steel is used as construction materials, as tube sheets, rods and bars. [ABSTRACT FROM AUTHOR]

Purpose: Over the past decade, plant extracts are ultimate green candidatures to substitute the expensive and noxious synthetic corrosion inhibitors. In this regard, this study aims to focus on evaluating anti-corrosion properties of green inhibitor Cyperus rotundus (C. rotundus), a perennial herb found throughout India. Design/methodology/approach: The biocompatible components present in C. rotundus extract was analyzed by gas chromatography–mass spectroscopy analysis. The corrosion inhibitory effect of C. rotundus was assessed by impedance, polarization and surface morphometric study [atomic force microscopy (AFM)]. Density functional theory (DFT) study was carried using DFT/B3LYP, and basis set used for calculations was 6-31G (d, p) using Gaussian 03 program package. Findings: Predominant components such as octadecanoicacid, ethylester, n-hexadecanoic acid, pentanoicacid-4-oxoethyl ester, cyclotrisiloxane, hexamethyl, cyclotetrasiloxane and octamethyl were identified from the extract of C. rotundus. Impedance study demonstrated that the addition of inhibitor reduces the double-layer capacitance and increases the charge transfer resistance. Furthermore, polarization studies indicated that the extract of C. rotundus acted as a mixed-type inhibitor with decrease in corrosion current density with increase in concentration. AFM study evinced the formation of inhibitor film on mild steel surface. The donor–acceptor interactions of active sites of predominant phytoconstituents were substantiated by computational analysis (DFT). Originality/value: This paper deals with the inhibition effect of extract of C. rotundus on mild steel in 0.5M H2SO4. C. rotundus has a capability to adsorb on the metal surface, thus hindering corrosion. [ABSTRACT FROM AUTHOR]

Purpose: In this paper, two promising corrosion inhibitors based on natural and eco-friendly materials such as peanut fatty acids (PFA) were prepared and challenged with a common efficient commercial inhibitor. Two amino derivatives based on aliphatic and aromatic compounds such as 2-amino-2-methyl-1-propanol (AMP) and 2-amino-2-phenyl-1-propanol (APP), respectively, were used and reacted with PFA under controlled conditions to produce the corrosion inhibitors. The prepared inhibitors, namely, PFA-AMP (inhІ) and PFA-APP (inhІІ), were confirmed and characterized by Fourier transfer infrared spectroscopy, acid value determination and viscosity measurements. Design/methodology/approach: First, different coating formulations free from any inhibitors were prepared and irradiated under different doses of electron beam source to select the best dose. Several concentrations of synthesized anticorrosion materials were then added to coating formulations to estimate them as anticorrosion materials for mild steel panels. Then, all formulations were coated and polymerized at a dose of 10 kGy. The corrosion tests, weight loss and water uptake were studied for all films after immersion in 3.5% sodium chloride. Moreover, the chemical and physico-mechanical properties were determined for all films. Findings: The results exhibited that the different concentrations of two inhibitors did not show any significant change on the different properties of all films, and the best concentration, which gives the better protection for steel panels, was to be 1.0 g for two inhibitors. Originality/value: It was found that the protection efficiency of the inhІ is better and higher than that of the inhІІ and also of the commercial inhibitor with the following order: inhІ > commercial inhibitor > inhІІ. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to find a way to improve the surface insulation, corrosion resistance and mechanical properties of Fe-Cr-Al electrothermal alloy, exploring the best oxidation condition and analyzing the oxidation mechanism. Design/methodology/approach: Electrochemical workstation was used for anodic oxidation, and the effect of current density, ethylene glycol concentration and oxidation time on properties of the film were investigated by resistivity test, scanning electron microscope, electrochemical tests (potentiodynamic polarization and electrochemical impedance spectroscopy) and mechanical tests, and the oxidation process was analyzed by X-ray photoelectron spectroscopy (XPS). Findings: According to the potential-time curves of anodic oxidation and the analysis of XPS, the whole oxidation process can be divided into four stages. When the current density is 0.8 A/dm2, the ethylene glycol concentration is 10%, and the oxidation time is 60 min, the film has the best corrosion protection, mechanical properties and surface morphology. The resistivity of the samples is about 13 orders magnitude than that of the matrix. Originality/value: In this paper, a protective electrically insulating film was prepared by anodic oxidation in an alkaline electrolyte solution. The oxidation conditions were optimized and the oxidation mechanism was analyzed. [ABSTRACT FROM AUTHOR]

Purpose: The authors have prepared the triazole film on copper surface by click reaction and explored its inhibition mechanism. Design/methodology/approach: The protective film is assembled by immersing bronze in solution containing p-toluenesulfonyl azide (TA) and propiolic acid (PA). Findings: Fourier transform infrared spectroscopy (FT-IR) indicates that triazole (TTP) film was formed on bronze surface via click chemistry reaction between TA and PA. It shows TTP film has a good protection for bronze in the atmospheric environment simulation solution. Quantum chemical calculation (QC) and molecule dynamics simulation suggests TTP molecule adsorbs on bronze surface via N and O. Originality/value: This is beneficial to develop the corrosion inhibitors for the corroded copper alloys. [ABSTRACT FROM AUTHOR]

Purpose: Polypyrrole (PPy) and PPy/metal oxide nanocomposites were synthesized by oxidative polymerization process, and its corrosion protection ability was studied by immersion test and electrochemical corrosion studies in 1 per cent HCl and 3.5 per cent NaCl solution. Design/methodology/approach: The prepared composites were loaded in acrylic resin and subsequently coated on a mild steel surface. The characterization of the polymer composites using FT-IR, UV-vis, XRD and FE-SEM with EDS analysis confirmed the interaction between PPy and metal oxide nanoparticles. The PPy nanoparticles were less protected on the mild steel, but the nanocomposite coating with metal oxide nanoparticles dramatically increased the corrosion resistance. Findings: According to the corrosion protection ability of the coating, it was demonstrated that the acrylic resin coating composed of PPy/metal oxide nanocomposites was highly efficient in protecting the mild steel compared to the PPy nanoparticles. The highest protection efficiency was obtained by PPy/TiO2 nanocomposites with acrylic resin coating. Originality/value: To the best of the authors' knowledge, this paper consists of original, unpublished work which is not under consideration for publication elsewhere and that all the co-authors have approved the contents of this manuscript and submission. [ABSTRACT FROM AUTHOR]

Purpose: Wire + arc additive manufacturing (WAAM) uses existing welding technology to make a part from metal deposited in an almost net shape. WAAM is flexible in that it can use multiple materials successively or simultaneously during the manufacturing of a single component. Design/methodology/approach: In this work, a gas metal arc welding (GMAW) based wire + arc additive manufacturing (WAAM) system has been developed to use two material successively and fabricate bimetallic additively manufactured structure (BAMS) of low carbon steel and AISI 316L stainless steel (SS). Findings: The interface shows two distinctive zones of LCS and SS deposits without any weld defects. The hardness profile shows a sudden increase of hardness at the interface, which is attributed to the migration of chromium from the SS. The tensile test results show that the bimetallic specimens failed at the LCS side, as LCS has lower strength of the materials used. Originality/value: The microstructural features and mechanical properties are studied in-depth with special emphasis on the bimetallic interface. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to investigate the effect of alternating current (AC) on corrosion, it is not yet clear about the exact mechanism of the corrosion induced by AC. Previous reports indicated that AC corrosion was similar to the effect of continuous cathodic and anodic polarization on the corrosion process of the metals. Wan et al. studied the effect of negative half-wave AC on stress corrosion cracking behavior and mechanism of X80 pipeline steel in near-neutral solution. Design/methodology/approach: This study attempted to understand the AC-induced corrosion by imposing the half-cycle AC on the X80 pipeline steel in an acid bicarbonate solution. The AC corrosion mechanism was determined by weight loss and potentiodynamic polarization curve measurements, as well as surface characterization. Findings: The results show that the positive half-cycle AC accelerated the uniform corrosion in the NaHCO3 solution, the negative half-cycle AC would decrease the uniform corrosion and local corrosion was increased and some Ca and Mg deposited on the surface of X80 steel, so the corrosion rate decreased by negative half-cycle AC. The corrosion product was composed of α-FeOOH under the application of positive half-cycle AC. The oxygen reduction led to a local increase of pH near the electrode surface and led to the formation of α-FeOOH, which enhanced the protectability of corrosion products. Originality/value: Researchers studied the effect of negative half-wave AC on stress corrosion cracking behavior and mechanism of X80 pipeline steel in near-neutral solution. However, the AC behavior and corrosion mechanism in acid solution are unknown. So to make clear about the corrosion behavior of metals in different polarization states and the mechanism involved, diode technology was used to research the AC corrosion, half-wave AC was applied on the metals after the full-wave rectified. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to study the corrosion performance and physical properties of hybrid paint systems based on zinc-rich primer (ZRP) and to determine the optimum modification approach that guarantees the most overall performance enhancement for the developed coating films that have been fabricated based on the usage of ZRP. Design/methodology/approach: Four different approaches were applied to enhance the corrosion protection performance and the physical properties of ZRP-based paint systems, namely, incorporation with TiO2 pigment, introducing SiO2 nanoparticles, usage of polyamide curing agent and application of epoxy base coating as a second layer. The physico-mechanical properties were examined using pull-off test, glossiness test, pencil hardness test and cross-cut adhesion tape test. Moreover, the contact angle measurement was used to study the wettability of the developed coated surfaces and the corrosion protection performances were evaluated by using electrochemical impedance spectroscopy and salt spray test. Findings: The obtained results revealed the ability of a certain approach to enhance the physical and corrosion protection properties of the ZRP paint system. Moreover, developing an intact hydrophobic nanocomposite paint system based on the usage of ZRP as the host matrix and SiO2 nanoparticles as the reinforcing agent was confirmed without altering the cathodic protection mechanism or the other desired characteristics of ZRP paint system. Originality/value: The innovation of this work can be clearly observed by the ability to enhance the physical and corrosion protection properties of ZRP with four different approaches. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to develop green/natural corrosion inhibitors. Adina cordifolia leaves extract (ACLE) was screened for its corrosion inhibition potential for mild steel (MS) corrosion in 0.5 M H2SO4 medium. Design/methodology/approach: Adina cordifolia (AC) leaves were subjected to cold ethanol extraction and concentrated after refluxed with double distilled water. The resultant concentrate was screened for corrosion inhibition studies using sequence of standard corrosion monitoring techniques, namely, gravimetric analysis, electrochemical studies and scanning electron microscopy (SEM). Findings: Gravimetric analysis provided evidence that the prepared ACLE showed dose dependent corrosion inhibition; impedance study revealed that the ACLE increases the charge transfer resistance and decreases double layer capacitance while polarization curves indicated that ACLE acts as a mixed-type inhibitor. Further studies over MS surface/test solutions through SEM and Fourier-Transform Infrared spectroscopy evident the formation of ACLE protective film protects MS. Practical implications: AC's methanol extract developed in this work can be used as a green corrosion inhibitor over industrial applications. Originality/value: For the first time, AC leaves were tested as corrosion inhibitors for MS corrosion in 0.5 M H2SO4 medium. The results evidenced that ACLE will be a promising corrosion inhibitor, which could be usable in industries as a green corrosion inhibitor. [ABSTRACT FROM AUTHOR]

Purpose: This study/paper aims to the authors applied low "Si" ions dose over cp-Ti-2, and the potent dose level was optimized for adequate corrosion resistance and effective proliferation of stem cells. Design/methodology/approach: The cp-Ti surface was modified by silicon (Si) ions beam at 0.5 MeV in a Pelletron accelerator. Three different ion doses were applied to the polished samples, and the surface was characterized by XRD and AFM analysis. Findings: At moderate "Si" ion dose (6.54 × 1012 ions-cm−2), the potential shifted to a noble value. The small "icorr" (1.22 µA.cm−2) and relatively large charge transfer resistance (43.548 kΩ-cm2) in the ringer's lactate solution was confirmed through Potentiodynamic polarization and impedance spectroscopy analysis. Compared to cp-Ti and other doses, this dose level also provided the effective proliferation of mesenchymal stem cells. Originality/value: The dosage levels used were different to previous work and provided the effective proliferation of mesenchymal stem cells. [ABSTRACT FROM AUTHOR]

Purpose: Laser melting deposition (LMD) is an advanced additive manufacturing (AM) technology without powder waste, and nickel-based alloys with different Nb contents were created one-time by adjusting the ratio of mixed powders via a dual-feed system. Here, the authors provide a systematic report on the effects of the Nb content on the microstructure, Laves phase segregation and mechanical properties of as-received LMD nickel-based alloys. The effects of the Nb content on the microstructure, precipitation evolution and mechanical properties of the subsequent heat-treated LMD samples are also discussed in this paper. Design/methodology/approach: Thus, the present research aims to obtain a better understanding of the effect of Nb content on the microstructural and mechanical properties of the as-received LMD Inconel 718 alloys through high-throughput sample fabrication. The microstructures were characterized by scanning electron microscopy and energy-dispersive spectroscopy, electron back-scattered diffraction and transmission electron microscopy methods. The mechanical properties were obtained from compressive tests and nano-indentation tests. Electrochemical tests, including electrochemical impedance spectroscopy and potentiodynamic polarizations, were carried out to evaluate the durability of the Inconel 718 alloys. Results can provide a factual basis for future applications of the functionally graded by AM technology. Findings: The grain size of the as-received LMD Inconel 718 alloys decreased with the Nb content. The Laves phase distribution at the macro level was relatively uniform and the Laves phase exhibited a 1.5-fold nano-hardness compared with the matrix. The strength improvement for the as-received LMD Inconel 718 alloys with Nb content was attributed to grain refinement and enhancement of the Laves phase in terms of both hardness and content. Meanwhile, the corrosion resistance increased with the increase of the Nb content, especially for the pitting potential, which was attributed to the optimization of carbide precipitates due to the strong affinity between niobium and carbon. Originality/value: The results provide a factual basis for the Nb content effect in LMD nickel-based alloys, and this method can greatly promote the development of new materials. The authors believe that this study makes a significant contribution to the literature and is suitable for publication. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to evaluate the inhibition efficiency (IE) of oxalate ions in controlling corrosion of aluminum at pH 10. Design/methodology/approach: The IE has been determined by the classical weight loss method. The corrosion behavior of aluminum was investigated by using potentiodynamic polarization and electrochemical impedance measurements. Ultra violet (UV)-visible and Fluorescence spectra have been used to analyze the film formed on the aluminum surface after immersion. Findings: The maximum IE was 88 per cent, which was offered by a mixture of 250 ppm oxalate ions and 50 ppm [Zn2+]. Potentiodynamic polarization data revealed that the protective film was formed on the metal surface. UV-visible and Fluorescence spectra indicated the presence of Al3+−oxalate complex in the protective film formed on aluminum substrate after immersion in [OX]/[Zn2+] solution. Originality/value: The findings of this work shed more light on the corrosion inhibition of aluminum by oxalate self-assembling monolayers. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to investigate the inhibition effect of a newly synthesized1,2,3-triazole containing a carbohydrate and imidazole substituents, namely, 1-((1-((2,2,7,7-tetramethyltetrahydro-5H-bis([1,3]dioxolo)[4,5-b:4′,5′-d]pyran-5-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-1H-benzo[d]imidazole (TTB) on the corrosion of mild steel in aerated 1 M H2SO4. Design/methodology/approach: The authors have used weight loss measurement, potentiodynamic polarization, electrochemical impedance spectroscopy, FT-IR studies, scanning electron microscopy analysis and energy dispersive X-ray (EDX) spectroscopy techniques. Findings: It is found that, in the working range of 298-328 K, the inhibition efficiency of TTB increases with increasing concentration to attain the highest value (92 per cent) at 2.5 × 10−3 M. Both chemisorption and physisorption of TTB take place on the mild steel, resulting in the formation of an inhibiting film. Computational methods point to the imidazole and phenyl ring as the main structural parts responsible of adsorption by electron-donating to the steel surface, while the triazol ring is responsible for the electron accepting. Such strong donating–accepting interactions lead to higher inhibition efficiency of TTB in the aqueous working system. Originality/value: This work is original with the aim of finding new acid corrosion inhibitors. [ABSTRACT FROM AUTHOR]

Purpose: The study aims to find new anticorrosive components from a plant source, namely, Pachysandra terminalis Sieb. et Zucc. (P. terminalis), a traditional medicinal shrub predominantly used by Tujia people. Design/methodology/approach: Because phenolic components from plants are known for its numerous values in several fields, the corrosion inhibitive ability of P. terminalis extract was analyzed by electrochemical studies (polarization, electrochemical impedance spectroscopy) and surface examination (by scanning electron microscopy [SEM], energy-dispersive X-ray spectroscopy [EDX] and atomic force microscopy [AFM]). Findings: The examination of total phenolic content (TPC), total flavonoids content (TFC) and individual phenols (UHPLC) showed the presence of 85.21 mg/g (TPC), 25.38 mg/g (TFC), protocatechuic acid (62.10 µg/g), gentisic acid (60.21µg/g), rutin (50.12 µg/g), kaempferol (46.58 µg/g) and p-Coumaric acid (42.35µg/g). The polarization study shows that the maximum shift is (16 mV), imposing a mixed mode of inhibition, dominantly anodic. The surface morphology studies by SEM, EDX and AFM confirmed the adsorption of phytochemical components on the low carbon steel surface blocking the active sites. Originality/value: The study unveils the inhibitive nature of P. terminalis, preventing aggressive attack by 0.5 M HCl on low carbon steel. This also exhibits few phenols present in methanolic leaf extract which may be the role player of corrosion inhibition. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to study the corrosion inhibition of Methyl 2-(benzamido)-2-(4-phenyl-1H-1,2,3-triazol-1-yl) acetate (MBPTA) and Methyl 2-(benzamido)-2-(4-p-tolyl-1H-1,2,3-triazol-1-yl) acetate (MBTTA) in 1 M H2SO4 solution at 25 °C. Design/methodology/approach: The authors have used weight loss measurements, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, FT-IR, quantum chemical calculations and scanning electron microscopy (SEM) techniques. Findings: The polarization measurements indicate that both compounds are mixed type inhibitors, and that MBTTA is more effective than MBPTA. The effect of temperature on the corrosion behavior using optimal concentration of MBTTA and MBPTA was studied in the temperature range 298-328 K. SEM was used to examine the morphology of the metal surface. Thermodynamic parameters were calculated and discussed. Monte Carlo simulations were applied to lookup for the most stalls configuration and adsorption energy for the interaction of inhibitors on Fe (1 1 1) interface. The difference in inhibition efficiencies between the two organic inhibitors can be clearly explained in terms of frontier molecular orbital theory. Originality/value: The authors report on the comparative inhibiting effect of two new 1,4-disubstituted 1,2,3-triazoles, namely Methyl 2-(benzamido)-2-(4-phenyl-1H-1,2,3-triazol-1-yl) acetate (MBPTA) and Methyl 2-(benzamido)-2-(4-p-tolyl-1H-1, 2, 3-triazol-1-yl) acetate (MBTTA) on mild steel corrosion in 1 M H2SO4 solution. [ABSTRACT FROM AUTHOR]

Purpose: Tannic acid (TA) is one of the green corrosion inhibitors for mild steel; its anti-corrosive performance in alkaline water on mild steel when it is used together with polyaspartic acid (PASA) still has not been investigated. The purpose of this study is to develop an effective, biodegradable and environment-friendly novel corrosion inhibitor based on TA and PASA as an alternative to the conventional inorganic inhibitors for mild steel in decarbonised water, which is common in cooling systems. Design/methodology/approach: Corrosion inhibition mechanism is investigated by electrochemical techniques such as polarisation measurements and electrochemical impedance spectroscopy, and results were evaluated to determine the optimum inhibitor concentration for industrial applications. Additionally, practice-like conditions are carried out in pilot plant studies to simulate the conditions in cooling systems. Thus, the efficiencies of the inhibitors are evaluated through both weight loss and linear polarisation resistance measurements. Moreover, the corrosion product is characterised by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR) analysis. Findings: TA shows high inhibition efficiency especially towards pitting corrosion for mild steel in decarbonised water. PASA addition in the cooling systems improves the inhibition efficiency of TA, and at lower concentrations of TA + PASA, it is possible to obtained better inhibition efficiency than TA alone at higher inhibitor amounts, which is essential in economic and environmental aspect. Originality/value: A blended inhibitor program including TA and PASA with suggested concentrations in this work can be used as an environmental friendly treatment concept for the mild steel corrosion inhibition at cooling systems. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this work is to investigate the effect of oxide-coated steel in comparison with mild steel fibers on the tribological and corrosion performances of friction composites.Design/methodology/approach In this study, the friction composites were developed in the form of standard brake pads by using oxide-coated steel and compared with mild steel fibers-based one without varying the other ingredients. The brake pads were developed as per the industrial procedure. The physical, mechanical, thermal properties of the developed brake pads were analyzed as per the industrial standards. The tribological properties were analyzed using the Chase test. The worn surface analysis was done using scanning electron microscope. Corrosion behavior was also analyzed in both salt and normal water conditions.Findings The experimental results indicate that the oxide-coated steel-based friction composites brake pads possess good physical, chemical, thermal, corrosion resistance and mechanical properties with stable fade and recovery characteristics because of its oxide coating and flake morphology.Originality/value This paper explains the influence of oxide-coated steel in friction composites for enhancing the tribological performance and corrosion resistance by its oxide coating and flake morphology which could potentially replace mild steel fibers-based problems in friction composites. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this paper is to propose cold spraying and laser cladding processes as alternatives to cadmium and chromium electroplating, respectively. There are many substances or chemicals within the coating technology that can be identified as substances of very high concern because of their carcinogenic or mutagenic nature. Cadmium and chromium undoubtedly belong to these items and are the basic constituents of electrolytic coating processes. Finding an alternative and adapting to the existing restrictions of the usage of such hazardous products stands for many to be or not to be in the market.Design/methodology/approach The research work was focused on down selecting the appropriate materials, producing the coating samples, testing their properties and optimizing process parameters by statistical method. On the one hand, the high-pressure cold spray system and spraying of the titanium coating on the landing gear component, and on the other hand, the high-energy laser cladding facility and the wear resistant cobalt-based coating deposited onto the shock absorber piston. Substrates of these two applications were made of the same material, 4330 – high-strength low-carbon steel.Findings Meeting the requirements of Registration, Evaluation, Authorization and Restriction of Chemicals implies undertaking research and implementation work to identify alternative processes. The work provides the technical characteristics of new coatings justifying application readiness of the researched processes.Originality/value Taguchi's design of experiment method was combined with the measurements and analysis of specified coating properties for the optimization of the cold spray process parameters. There is also laser cladding process development presented as a fast rate technology generating coatings with the unique properties. [ABSTRACT FROM AUTHOR]

Purpose This paper aims to appraise the inhibitory effect of saponins extracted from Gongronema latifolium (SEGL) on mild steel in acid media. This is in a bid to conserve our environment and maintain the integrity of engineering structures and materials.Design/methodology/approach The corrosion inhibition of SEGL and ethanolic extracts of the leaves of G. latifolium (EEGL) on mild steel was studied by hydrogen evolution technique within a temperature range of 30-60°C in tetraoxosulphate (VI) acid solutions.Findings The extracts inhibit the corrosion of mild steel, and the inhibition efficiency depends on the concentration of the plant extract, temperature and the period of immersion. SEGL was comparatively more efficient than EEGL. Optimum values of the inhibition efficiency for both the EEGL and SEGL (93.7 and 96.5 per cent, respectively) were obtained at extract concentration of 10 g/L, whereas the least values were obtained at extract concentration of 0.5 g/L.Originality/value This paper provides new information on the possible application of isolated SEGL as an environmentally friendly corrosion inhibitor. The possible mechanism of the inhibitive action is also given. [ABSTRACT FROM AUTHOR]

Purpose This paper aims to study inhibitory effect of 4-aminothiophenol on the corrosion of mild steel (MS) in 0.5 M HCl.Design/methodology/approach In this study, electrochemical experiments, quantum chemical calculations, potentiodynamic measurements, linear polarization resistance and scanning electron microscopy were used.Findings The experimental results suggest that this compound is efficient corrosion inhibitor and the inhibition efficiencies increase with increasing their (from 0.5 to 10.0 mM.) concentrations. This reveals that inhibitive actions of inhibitors were mainly due to adsorption on mild steel surface. The adsorption of these inhibitors was found to obey Langmuir adsorption model. The computed quantum chemical features show good correlation with empirical inhibition efficiencies.Originality/value The 4-aminothiophenol is suitable inhibitor for application in closed-circuit systems against corrosion. The study is original and has great impact in industrial area. The obtained theoretical results have been adapted with the experimental data. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this paper is to test the Natural Kermes dye (NKD) as a cheap and stable corrosion inhibitor for mild steel in 1.0 M HCl and its adsorption mechanism on the steel surface.Design/methodology/approach The inhibition action of NKD was studied using AC impedance, potentiodynamic polarization, scanning electron microscope (SEM) and UV-visible spectra techniques complemented with quantum study.Findings Here, the authors show that addition of NKD inhibits effectively the corrosion of steel in HCl solution via its adsorption on the steel surface. The inhibition efficiency of NKD increases with increase in its concentration and decreases with temperature. Potentiodynamic results revealed that NKD acts as a mixed–type inhibitor. Thermodynamic parameters for corrosion and adsorption process were obtained from the experimental data. Moreover, the experimental inhibition efficiencies were correlated with the electronic properties of NKD using density functional theory.Originality/value To the best of the authors’ knowledge, this is the first report showing the effect of NKD on the corrosion inhibition of steel. [ABSTRACT FROM AUTHOR]