Anticorrosion Efficiency Research Articles

Smart nanoarchitectonics of epoxy coating: Preparation, release behavior and self-healing performance based on mesoporous silica nano-containers loaded with DMTD inhibitors

Self-healing coatings doped by nano-containers loaded with inhibitors have shown remarkable anti-corrosion efficiency and durability in extending metal life and slowing down coating failure. However, low loading capacity of corrosion inhibitors in nano-containers is a problem plaguing the further development and application of smart coatings. In this study, mesoporous silica with large pore sizes (MSN) was synthesized using the soft template method which significantly increased the loading capacity of the corrosion inhibitor, and a smart self-healing composite coating was designed, which could protect carbon steel from corrosion and provide durable protection for it. Specifically, the composite coating (EP/DMTD@MSN-PAA) was prepared by incorporating mesoporous silica nano-containers embedded with 2,5-dimercapto-1,3,4-thiadiazole (DMTD) molecules into the epoxy resin coating. The results of BET test showed that the prepared MSNs had high specific surface area (734.97 m2/g) and large pore volume (0.85 cm3/g). The thermogravimetric (TG) analysis showed 35.7% of loading amount of corrosion inhibitors in the nano-materials. Response release experiments showed that the DMTD@MSN-PAA had of acid-response release characteristics. When pH value of the system decreased from 7 to 3, the release amount of the DMTD molecules increased from 40.3% to 93.7%. The contact angle test showed that the epoxy resin (EP) coating had a contact angle value of 57.7°, while those of the composite coatings doped with 1 wt%, 3 wt% and 6 wt% DMTD@MSN-PAA (EP/DMTD@MSN-PAA) were 65.1°, 75.2° and 67.2°, respectively. These results indicated that the composite coatings had better hydrophobicity compared to the EP coating, and were conducive to prolonging the coating service time. The anti-corrosion performances of both the EP and the composite coatings with different doping amounts of DMTD@MSN-PAA were evaluated by EIS measurements. The Rct value of the EP coating decreased from 190.3 to 25.1 Ω · cm2 within the time of 48 h of immersion in 3.5 wt% NaCl solution, while ones of the EP/DMTD@MSN-PAA coatings doped with 1 wt%, 3 wt% and 6 wt% of DMTD@MSN-PAA increased from 303.1, 720.7.7, 523.4–1426.4, 2113.8, 1066.3 Ω · cm2, respectively. In addition, the corrosion resistance of the EP and composite coatings were further evaluated by etching experiments. The results showed that after 35 d of immersion, compared with that of the EP coating, surface corrosion degree of the composite coatings was lower, and the scaling off speed of the coatings slowed down, which further proved that the composite coating had strong corrosion resistance and special self-healing characteristics.

Corrosion analysis and performance investigation of hybrid MXene/C-dot Nanofluid-Based direct absorption solar collector

Nanofluids having exceptional thermo-optical characteristics can enhance the performance of direct absorption solar collectors (DASC). Conventional nanofluids have either high optical properties or thermal properties. In this study, carbon quantum dot (C-dot) nanomaterial with high stability and optical absorption along the UV range, and MXene nanoparticles with high thermal conductivity and absorption along visible and near-infrared (NIR) spectral range was selected for synthesizing a hybrid nanomaterial with synergistic thermo-optical properties. Hybrid MXene/C-dot nanofluid exhibits higher stability, thermal conductivity, and complementary absorption properties of individual nanomaterials. A two-step method was used for the synthesis of nanofluids using water as the base fluid. Thermal conductivity, UV–Vis-NIR spectroscopy, and stability analysis were conducted on nanofluids, and the concentration was optimized for corrosion study and application in direct absorption parabolic trough collector (DAPTC). Optimised concentrations of C-dot, MXene, and hybrid nanofluids were 0.15 wt%, 0.1 wt% and 0.15 wt%, respectively. The corrosion study states that copper electrodes dipped in the hybrid nanofluid exhibited the least corrosion rate of 0.6 mm/year with an anticorrosion efficiency of 64.5 % over DI water. Thermal efficiency and entropy generation in the system with different HTFs were measured and compared with that of the base fluid. The study shows that C-dot and MXene/C-dot nanofluids were producing the highest efficiencies of 50.5 % and 47.5 % at a flow rate of 1.2 lpm. This study shows that hybrid MXene/C-dot nanofluid exhibited exceptional thermal stability, reduced corrosion effects, and considerable enhancement in photothermal conversion efficiency of the DASC.

Improving the barrier properties of chitosan coatings through Schiff base formation and halloysite incorporation for corrosion protection of commercially pure aluminum (cp-Al).

Coatings of chitosan modified with vanillin and containing halloysite nanotubes as filler were produced for corrosion protection of commercially pure aluminum (cp-Al). Modifications were characterized by Fourier-transform infrared spectroscopy (FTIR) and the degree of modification was determined by the ninhydrin assay, using UV–vis spectroscopy. Chitosan-modified coatings had their anticorrosive performance evaluated in 3.5 wt% NaCl solution through linear polarization and electrochemical impedance spectroscopy (EIS). Results showed an increase in the anticorrosive efficiency of the films with the increase of the degree of modification, which was related to the decrease of the electrolyte permeation through the coatings. The effect of the filler’s addition was evaluated by EIS analysis, SEM images coupled with EDS and analysis of the degree of swelling in 3.5 wt% NaCl. The electrochemical assays demonstrated that the addition of halloysite in low concentrations (up to 1%) improves the barrier properties of the films leading to a higher anticorrosive efficiency. It was also observed that with 10% halloysite occurs a phase separation responsible for the expressive increase in the degree of swelling of the samples and loss of barrier properties.

Investigation of phosphorus-based ionic liquid with long alkyl chain as high-performance corrosion inhibitor with ultralow concentration for mild steel in 1 M HCl solution

The ionic liquids (ILs) are regarded as the ideal candidate for the novel and high-efficiency corrosion inhibitors. While the cost problem caused by relatively large dosage limited the wide employments of conventional ILs. In the current study, we synthesized two novel phosphorus-based ionic liquids (PBILs) with different alkyl chain length (dodecyltriphenylphosphonium bromide (C12TPB) and cetyltriphenylphosphonium bromide (C16TPB)), and evaluated their anticorrosion efficiencies for mild steel (MS) in 1 M HCl aqueous solution by weight loss measurement, scanning electron microscope, X-ray photoelectron spectroscopy and electrochemical test. The results revealed that PBILs performed excellently (inhibition efficiencies > 93 %) at a very low concentration of 10 μM, which was much greater than those for traditional imidazole and pyridine ionic liquids at 500 μM. It was demonstrated that PBILs could adsorb on the metal surface to form the protective film, which should be mixed corrosion inhibitors with cathodic advantage. Then the adsorption study and molecular dynamics simulation confirmed that their special molecular structure highly promoted the intensity of the adsorption film mainly caused by the chemical adsorption. This study provided a novel approach for the structural design and development of high-performance IL corrosion inhibitors.

A smart platform for monitoring the whole life-course of self-healing coatings with the cooperation of self-reporting microcapsules and coating matrix

Constructing a smart system with the capability to self-report the whole life-course of self-healing coatings, containing damage, self-healing, and restoration of protection capability after maintenance of large-scale damages, is a formidable challenge. In this study, we propose a facile strategy to address this issue by developing an intelligent platform using acrylic coating containing pH-responsive microcapsules loaded with phenolphthalein indicator. Upon damage, the color probes are released from the microcapsules and turn pink to locate cracks due to increased pH in the cathode region. The smart platform enables the sequencing of anticorrosion dynamics for various self-healing coatings as the slender pink color resulting from the low hydroxide ion generation rate signals the high anticorrosion efficiency. The highest-performance coating containing smart microspheres loaded with cerium acetate as corrosion inhibitors was easily screened, which was validated using electrochemical impedance spectroscopy (EIS). Furthermore, the hydroxide ions generated during electrogalvanic reactions could be consumed by coating matrix of acrylic resin through ester hydrolysis after repairing cracks. Hence, smart platform can be employed to evaluate the restoration of coating protection by monitoring the disappearance of the pink color. This facile yet effective strategy exhibits tremendous potential for real-time monitoring of the entire life-cycle and rapid screening of excellent self-healing coating formulations.

A robust superhydrophobic coating of SER/ ZnO/MWCNTs with high corrosion resistance was prepared by one-step spraying method

Multifunctional integration is the basic feature of artificial superhydrophobic coatings widely used in many fields. This paper presents a simple and economical experimental method to prepare a super hydrophobic coating with super strong corrosion resistance by spraying a mixed solution composed of epoxy resin (EP) as the base, multi-walled carbon nanotubes (MWCNTs), sericite (SER), nano-zinc oxide (ZnO) and octadecyl trimethoxysilane (ODTMS) on an aluminum substrate. Firstly, the superhydrophobic property of the coating prepared in this experiment is better than that of the ordinary coating, and its contact angle reaches 167.3° and rolling angle is as low as 2.7°. Secondly, the superhydrophobic coating can not only maintain the superhydrophobic property in harsh environment (such as: soaking in boiling water for 10 hours, soaking in acid, alkali and salt solution for 7 days, high temperature, burning and strong ultraviolet irradiation, etc.), but also can withstand a variety of mechanical damage without losing the superhydrophobic property (such as: 1000 sandpaper wear cycles, 100 tape stripping cycles and 1000 g grit sustained impact). In addition, the excellent non-wettability of superhydrophobic coating can make it have excellent performance in the field of selfcleaning and anti-fouling. It is worth mentioning that the electrochemical workstation experiment proved that the coating also has good corrosion resistance, and the anticorrosion efficiency reached 99.924%. This strong superhydrophobic coating has many functions, such as self-cleaning, antifouling and corrosion prevention, and will have good application prospects in many fields in the future.

Технология производства защитных антикоррозионных материалов из жиросодержащих отходов

The processing of fat-containing waste from meat-packing enterprises that cannot be landfilled is an urgent problem. The authors developed the technology of processing fat-containing waste in a chemical reactor in one step, without dividing the technology into two steps: triglyceride hydrolysis and fatty acid amide production. The technology for processing fat-containing waste was tested in a laboratory plant. The target product obtained was analyzed using IR spectroscopy. As a result, the structural formula was clarified, functional groups were determined, and chemical intermediates in the synthesis process were identified. The proportions of the reagents were determined: technical fat in the amount of 65.3‑72.4 wt%, monoethanolamine - 14.5‑17.0 wt% and boric acid - up to 100 wt% of the mixture. The reaction time was 1.5 h. The protective effect was selected as a quality control indicator of the surfactant obtained. Solvent selection was carried out for producing anticorrosive materials. I‑20 industrial oil, diesel fuel and SN‑150 oil were selected as solvents. Electrochemical studies carried out on the AVTOLAB PGSTAT302N potentiostat-galvanostat made it possible to determine the mechanism of action of the surfactant as a corrosion inhibitor. Its optimum concentration was found to be 15%, with a protective efficiency of 99.33%. To increase the protective anticorrosive efficiency of the surfactant, the tests were carried out in a humidity chamber for 60 days on St3 steel plates. The test results showed high efficiency of the surfactant used as a corrosion inhibitor, with the Z value of more than 90%.

Effect of the composition of alkylphosphonic acid solutions and the initial surface morphology on the anticorrosion efficiency of phosphonate–siloxane films formed on zinc

Effect of the composition of alkylphosphonic acid solutions and the initial surface morphology on the anticorrosion efficiency of phosphonate–siloxane films formed on zinc

Anticorrosive Efficiency of the AISI 316 SS in Sustainable Ecological Concrete Manufactured with SCBA-SF Exposed to Magnesium Sulphate

In this research, it was evaluated the anticorrosive efficiency of AISI 316 SS embedded in Sustainable Ecological Concrete (SEC) manufactured with partial substitutions of Portland Cement by combinations of SCBA and SF in 10%, 20%, and 30%. For the electrochemical evaluation, the Sustainable Ecological Concretes (SEC) were exposed to solution at 3.5% of MgSO4, these aggressive ions are found in soils, industrial or marine environments and that interact with the civil works that are built in these places. The dosage or proportioning of the Sustainable Ecological Concrete (SEC) mixtures was carried out as indicated by ACI 211.1. The anticorrosive efficiency of the AISI 316 SS was evaluated through the tests of the potential of corrosion (Ecorr) and corrosion rate (Icorr) during a period of 180 days of exposition to the aggressive medium. The values of Ecorr indicate in the AISI 316 SS a 10% of corrosion risk and uncertainty at the end of monitoring, according to the norm ASTM C-876-15, in all the mixtures, but the values of Icorr in the specimens manufactured with SEC indicate resistance to sulfate corrosion more than 10 times compared to conventional concrete and AISI 1018 steel.

Anticorrosive and antimicrobial efficiency of photopolymerizable phosphorus (meth)acrylate oligomers-based coating materials

Novel photopolymerizable phosphorus (meth)acrylate oligomers were verified as anticorrosive and antimicrobial coating materials. Oligomers containing P-atoms were prepared by a solution-free UV-initiated telomerization process of aliphatic (meth)acrylates and styrene in the presence of different organic phosphorus compounds (P-telogens). The influence of the P-telogen structure on the photoaging process of coatings, as well as their anticorrosion and antibacterial properties was investigated. Relatively the highest anticorrosive efficiency was revealed for a varnish based on a telomers syrup containing dibutyl phosphite (DBPh) and dibutyl phosphate (DBP) due to the relatively long alkyl chain. In turn, UV-photocurable coatings exhibited moderate antibacterial and good anti-yeast activity but the best properties were found for the coating with dimethyl phosphite (DMPh). The higher resistance to photodegradation was observed in the case of the diphenyl phosphite (DPPh) due to the large phenyl substituent. Regardless of the structure of the organophosphorus compound, all coatings showed excellent adhesion to the glass substrate.

Antireflection Property and Corrosion Resistance of Black Ceramic Superhydrophobic Coatings on Aluminum Alloy

In this article, a black ceramic coating is produced on the surface of 7075 aluminum alloy by plasma electrolytic oxidation (PEO) in a silicate electrolyte containing ammonium metavanadate (NH4VO3). The PEO processed sample is further subjected to hydrothermal treatment (HT) and fluorination treatment (FT) to obtain a superhydrophobic PEO/HT/FT coating. The 21‐day air durability test and the tape stripping test show that the superhydrophobic surface shows excellent air durability and mechanical durability. The antireflection test study shows that the average antireflection of the PEO/HT/FT coating is as high as 96.6% in the wavelength range between 400 and 1000 nm. Furthermore, electrochemical test results show that the corrosion current density of the PEO/HT/FT coating decreases to 2.49 × 10−6 A cm−2, three orders of magnitude lower than the aluminum substrate, and the anticorrosion efficiency is as high as 99.87%. The preparation of PEO/HT/FT coating provides more methods for the wide application of Al alloy in aerospace field.

Synergistic mixture of Capsicum annuum fruit extract/KI as an efficient inhibitor for the corrosion of P110 steel in 15 % HCl solution under hydrodynamic condition

Abstract The primary goal of this study is to discover a sustainable, renewable, and ecologically friendly anticorrosive inhibitor. Anticorrosion analysis of Capsicum annuum fruit extract (CAFE) was examined under hydrodynamic solution at 1500 rpm in 15 % on P110 steel. Results of the assessment showed that CAFE inhibits the corrosion of P110 steel and the rate of corrosion is significantly reduced on increasing its dosing amount. CAFE exhibits the maximum anticorrosive efficiency to 89.5 % (CAFE/800 mg/L) and 92.2 % (CAFE + KI/600 mg/L). The CAFE shows the chemical nature of inhibition effect. The maximum and minimum charge transfer resistance (R ct) and double layer capacitance (C dl) are 239.5 Ω cm−1 and 27 μF/cm2 with the addition of CAFE indicate the corrosion inhibition mitigation. The corrosion mitigation is caused by the adsorption of CAFE molecules on P110 steel surface via Temkin isotherm with chemical mechanism adsorption. The metal surface appearance was visualized via scanning electron microscopy (SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). The interaction among the most active constituent i.e., Capsaicin (RCM) sulfate reducing bacteria (SRB) protein was examined by molecular docking. Additionally, an atomic level study of RCM was performed using DFT and MD.

Preparation and Testing of Anti-Corrosion Properties of New Pigments Containing Structural Units of Melamine and Magnesium Cations (Mg2+)

This paper deals with the properties and testing of newly prepared organic pigments based on melamine cyanurate containing magnesium or zinc cations depending on their composition and anticorrosive properties in model coatings. Organic pigments based on melamine cyanurate with Mg2+ in the form of a complex differing in the ratio of melamine and cyanurate units were prepared. Furthermore, a pigment based on melamine citrate with magnesium cation Mg2+, a pigment based on melamine citrate with magnesium cation, and a pigment based on melamine cyanurate with zinc cation were prepared. The properties of Mg-containing organic pigments were also compared with those of selected magnesium-containing inorganic oxide-type pigments. The above-synthesized pigments were characterized by inductively coupled plasma-optical emission spectroscopy, elemental analysis, scanning electron microscopy, and X-ray diffraction. In addition, the basic parameters that are indicative of the applicability of the pigments in the binders of anti-corrosion coatings were determined. The anti-corrosive properties of the tested pigments were verified after application to the epoxy-ester resin-based paint binder in three different concentrations: at pigment volume concentrations of 0.10%, 0.25%, and 0.50%. The anticorrosive effectiveness of pigmented organic coatings was verified by cyclic corrosion tests in a salt electrolyte fog (NaCl + (NH4)2SO4) in an atmosphere containing SO2 and by the electrochemical technique of linear polarization. Finally, the effect of the structure of the pigments on the mechanical resistance of the organic coatings was investigated. The results obtained showed that the new organic pigments exhibit anticorrosive properties, and at the same time, differences in performance were found depending on the structure of the pigments tested. Specifically, the results of cyclic corrosion tests and the electrochemical technique of linear polarization clearly demonstrated that synthesized pigments of the organic type based on melamine cyanurate containing magnesium or zinc cations ensure the anti-corrosion efficiency of the tested organic coatings. The highest anti-corrosion efficiency was achieved by the system pigmented with synthesized melamine cyanurate with magnesium cation (C12H16MgN18O6), whose anti-corrosion efficiency was comparable to the anti-corrosion efficiency of the tested inorganic pigment MgFe2O4, which was prepared by high-temperature solid-phase synthesis. In addition, these organic coatings achieved high mechanical resistance after being tested using the most used standardized mechanical tests.

Green corrosion inhibitor for mild steel extracted from soybean leaves

The use of green-soluble inhibitors in the corrosive medium as alternatives to traditional inhibitors has increased due to the toxicity of the commonly used substances. These novel substances are selected owing to their low cost, ease of application as well as maintenance, and low environmental risk. This work aims to evaluate ethanolic-water extracts from post-harvest soybean (Glycine max) by-products as corrosion inhibitors for mild steel in an aggressive medium of sodium chloride. Soybean extracts were obtained by percolation at a controlled flow rate and temperature. To evaluate the anticorrosive efficiency, polarization curves of AISI 1030 steel were carried out at 1 and 7 days of immersion with different concentrations of the soybean extract. Weight loss measurements were carried out alongside potentiodynamic measurements. The steel samples were analyzed by scanning electron microscopy. The soybean extracts obtained reduced the corrosion rate of the steel, showing an efficiency of 30% at day 1. The inhibition efficiency increased up to 80% after 7 days of incubation with 2000 ppm of the extract. A Langmuir adsorption model was fitted to weight loss measurements. Kads and ΔGads obtained from the model were characteristic of physisorption. The corrosion potential was shifted toward more negative values, classifying the ethanolic-water soybean extract as a cathodic inhibitor. The steel surface for the samples incubated with 2000 ppm of soybean extract was greatly improved showing significantly fewer agglomeration of corrosion products. Soybean leaves are a promising by-product useful to produce ethanolic-water extracts to be used as green corrosion inhibitors.

Experimental and theoretical evaluation of the anticorrosive proprieties of new 1,2,3-triazolyl-acridine derivatives

Three novel 1,2,3-triazolyl-acridine derivatives (abbreviated as TTA, ATM, and ATA) were synthesized via a fast ultrasound-assisted copper-catalyzed azide-alkyne cycloaddition (CuAAC) in good yields. They were studied as corrosion inhibitors for 1020 mild steel in acidic media (1 mol/L HCl) using gravimetric and electrochemical measurements. Weight Loss Study showed that those molecules have anticorrosive efficiency varying from 85 to 94 % at 1 mmol/L (298 K). They also increased their corrosion mitigation at higher temperatures, reaching up to 90–96 % at 338 K. Isotherm fitting revealed that all developed corrosion inhibitors follow the Langmuir theory and data crossing confirmed the monolayer formation. Atomic Force Microscopy suggested the presence of a protective film on the metal surface and Electrochemical Impedance Spectroscopy, Linear Polarization Resistance, and Electrochemical Frequency Modulation showed a better charge transfer and polarization resistance alongside a lower corrosion current density in the presence of TTA, ATM, and ATA in the corrosive media. Also, polarization curves characterized all three organic molecules as mixed-type corrosion inhibitors for mild steel. First-principles density functional theory (DFT) simulations revealed that all molecules form covalent bonds with iron atoms upon adsorption on Fe(110) surface. The ATA molecule exhibited a bond-breaking upon adsorption and had a higher interaction energy with the iron surface. The chemical interactions between inhibitors’ molecules and iron atoms were confirmed by projected density of states analysis, showing a strong hybridization between molecules’ orbitals and 3d iron orbitals.

Expired Antifungal Drugs as Effective Corrosion Inhibitors for Carbon Steel in 1 M HCl Solution: Practical and Theoretical Approaches.

The anticorrosion potency of two expired antifungal drugs, namely, bifonazole (BIF) and terconazole (TER), for X65 carbon steel (X65CS) in a 1.0 M HCl solution was estimated using practical and computational measurements. The results of all methods applied showed that the percentage of anticorrosive efficacy (% AE) increased for expired BIF and TER and reduced at elevated temperatures. The % AE values of expired BIF and TER (375 mg L-1) reached 92.08 and 94.19%, respectively, using polarization methods. The anticorrosion activities of the two expired drugs were interpreted based on their adsorption on the X65CS surface. The adsorption occurred according to the Langmuir isotherm model. The polarization results indicated that the expired drugs BIF and TER were mixed inhibitors. The impedance results showed a single capacitive loop, confirming that the charge transfer process controlled the corrosion of X65CS. Expired BIF and TER served as good pitting inhibitors by shifting the pitting potential to positive values. The thermodynamic functions of activation and adsorption were defined and explained. Density functional theory and Monte Carlo simulations were used to investigate the BIF and TER inhibitors. The theoretical parameters were consistent with the experimental results. The anticorrosion efficiencies determined using the various methods were in complete agreement.

Zinc carboxylate optimization strategy for extending Al-air battery system's lifetime

Although Al-air batteries are expected to be the candidates for energy conversion systems in renewable energy market due to the higher energy density, richer reserves, and lighter mass of Al metal, the anode self-discharge is seen as a notorious issue that seriously sacrifices battery durability and stability. Herein, we propose zinc carboxylate inhibition of anode self-discharge for enhancing Al-air battery's lifetime, where the ionized Zn2+ induces a Zn guard on Al surface, and the hydrolysate RCOOH dominates an adsorption layer on the outer surface of Zn, ensuring a double protection for metal anode by means of advanced “one stone two birds” strategy. The results show that the typical zinc carboxylates improve the absolute anticorrosion efficiency of anode greatly, especially the maximum of 92.24% after zinc malate optimization. Furthermore, battery capacity and anode efficiency are as high as 2685.20 mAh g−1 and 90.11% at 20 mA cm−2 respectively. The cyclic discharge lifetime of system (0.12 g fuel) exceeds 19.01 h, which is 1.72 times longer than traditional optimization. Finally, the optimization mechanism is revealed based on Monte Carlo simulation and density functional theory calculation, which the double CO groups in the hydrolysate of zinc malate dominates the harmonious interaction between RCOOH adsorption layer and active metals, exhibiting a high-energy efficiency and long-lifetime Al-air battery power system.

New Azo Dyes-Based Mg Complex Pigments for Optimizing the Anti-Corrosion Efficiency of Zinc-Pigmented Epoxy Ester Organic Coatings

This work addresses the possibilities of using synthesized novel magnesium complex dyes in zinc pigmented organic coatings based on epoxyester resin to reduce the zinc content in these coatings while maintaining or increasing the anticorrosive efficiency of them. The magnesium complexes Mg-Dye-I (C34H26MgN8O6), Mg-Dye-II (C26H19MgN3O5), Mg-Dye-III (C17H10MgN2O3), and Mg-Dye-IV (C25H18MgN4O6) with a series of azo carboxylate ligands were prepared from the diazo-coupling reaction of anthranilic acid with 5-methyl-2-phenyl-3-pyrazolone (Dye I; C17H14N4O3), anthranilic acid with naphthol AS-PH (Dye II; C26H21N3O5), anthranilic acid with 2-naphthol (Dye III; C17H12N2O3), and 2-amino-5-nitrophenol with naphthol AS-PH (Dye IV; C25H20N4O6). The synthesized novel magnesium complex dyes were characterized by analytical methods. Model coatings containing these dyes at pigment volume concentrations (PVCs) = 1, 3, 5 and 10% and zinc at a ratio of pigment volume concentration/critical pigment volume concentration (PVC/CPVC) = 0.60 were formulated to study the inhibitory properties of the individual synthesized magnesium complex dyes. Model coatings containing inorganic pigments (MgO and Ca-Mg-HPO4) at PVCs = 1%, 3%, 5% and 10% and zinc at PVC/CPVC = 0.60 were also formulated. The coating pigmented only by zinc at PVC/CPVC = 0.60 was prepared as a standard organic coating. Corrosion resistance was also evaluated by potentiodynamic polarization studies and electrochemical impedance spectroscopy. The properties of organic coatings were also tested using other standardized and derived corrosion tests. In addition, the mechanical properties of the studied organic coatings were determined using standard tests. The aim of the work was to verify the possible synergistic efficiency of novel magnesium complex dyes by improving the mechanical, anti-corrosion, and chemical properties of zinc pigmented organic coatings.

Synergistic Effect of Nanoparticles: Enhanced Mechanical and Corrosion Protection Properties of Epoxy Coatings Incorporated with SiO2 and ZrO2.

This research paper presents the fabrication of epoxy coatings along with the hybrid combination of SiO2 and ZrO2. The epoxy resin is incorporated with SiO2 as the primary pigment and ZrO2 as the synergist pigment. The study delves into the adhesion, barrier, and anti-corrosion properties of these coatings, enriched with silica and zirconium nanoparticles, and investigates their impact on the final properties of the epoxy coating. The epoxy resin, a Diglycidyl ether bisphenol-A (DGEBA) type, is cured with a polyamidoamine adduct-based curing agent. To evaluate the protective performance of silica SiO2 and zirconia ZrO2 nanoparticles in epoxy coatings, the coated samples were tested in a 3.5% NaCl solution. The experimental results clearly demonstrate a remarkable improvement in the ultimate tensile strength (UTS), yield strength (YS), and Elastic Modulus. In comparison to using SiO2 separately, the incorporation of both ZrO2 and SiO2 resulted in a substantial increase of 43.5% in UTS, 74.2% in YS, and 8.2% in Elastic Modulus. The corrosion test results revealed that the combination of DGEBA, SiO2, and ZrO2 significantly enhanced the anti-corrosion efficiency of the organic coatings. Both these pigments exhibited superior anti-corrosion effects and mechanical properties compared to conventional epoxy coatings, leading to a substantial increase in the anti-corrosion efficiency of the developed coating. This research focuses the potential of SiO2 and ZrO2 in hybrid combination for applications, where mechanical, corrosion and higher adhesion to the substrates are of prime importance.

Influence of WC ceramic particles on structures and properties of laser cladding Ni50-WC coatings

This study reported the fabrication of Ni50 and Ni50-WC coatings while employing the laser cladding manufacture (LCM) technique. The surface and cross-sectional morphologies, microhardness, phase structure, corrosion, and wear resistances of the coatings were measured using a scanning electron microscope (SEM), stereoscopic microscope, X-ray diffractometer (XRD), microhardness tester, electrochemical workstation, and friction and wear tester. These results illustrated the emergence of γ-(Ni, Fe), WC, W2C, M23C6, M7C3, and Ni3Fe phases in Ni50–10WC and Ni50–20WC coatings. Besides, W and C contents were higher in Ni50–20WC coating than that in Ni50–10WC coating. The average microhardness of the Ni50–10WC and Ni50–20WC coatings was 655.2 HV and 817.9 HV, respectively, which tripled or quadrupled the substrates' average microhardness. Among all coatings, Ni50 had the lowest corrosion potential value of −0.83 V, indicating poor anti-corrosion efficiency. Ni50–10WC and Ni50–20WC coatings had wear depths of approximately 13.1 μm and 8.3 μm, respectively indicating the outstanding wear resistance of all coatings. Furthermore, the Ni50–20WC coating exhibited the lowest average friction coefficient (0.41) of all coatings because of its fine and compact structure.