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Electroplating enhances the mechanical, thermal, and tribological properties of components in industries like aerospace, computing, pharmaceuticals, and telecommunications. To achieve high-quality electroplated coatings, control of process parameters is essential. This study focuses on the challenges associated with the black nickel electroplating process, particularly its nonlinearity which makes traditional linear methods inadequate. We employed machine learning techniques to develop models capable of predicting defects, coating colour, and coating mass specifically for black nickel electroplating process adhering to the MIL-P-18317 specification, a boric acid-free method that is more environmentally friendly but more sensitive to bath conditions, hence making process optimization more challenging. Our research addresses significant gaps in the literature, focusing on boric acid-free black nickel plating, which requires unique modelling approaches different from other electroplating processes. Unlike previous studies that mainly focused on predicting coating mass, our models also predict defects and colour, ensuring comprehensive quality control. The best-performing models achieved an F1 score of 0.9875 for defect prediction, an F1 score of 0.95 for colour prediction, and R 2 = 0.9561, MAE = 0.0039, and MSE = 0.00001 for mass prediction. Additionally, we developed a novel optimization algorithm based on these models to fine-tune process parameters, ensuring that the resulting coatings meet strict standards for quality, appearance, and productivity. The validity of our approach was confirmed through experimental results. This research demonstrates how machine learning can help surface finishers, by providing effective strategies for optimizing processes in nonlinear scenarios, thereby improving product quality and productivity. [ABSTRACT FROM AUTHOR]

Cotton gauze (CG) is the most commonly used primary wound dressing to protect wounds from the external environment. However, it is highly susceptible to fouling due to the adhesion of bacteria present on the wound surface. Bacterial colonization of the dressing is detrimental as it aids in wound infection and delays wound healing. To mitigate this issue, the objective of this study was to transform the inert CG into a fouling-resistant wound dressing that can actively resist bacterial adhesion and also prevent biofilm formation on the surface of cotton. In this work, a facile method of modifying commercial CG using oxidized dextran (Odex) was developed. Odex was derived from dextran via periodate oxidation reaction and then coated over the CG using mussel-inspired chemistry. The resultant Odex-modified CG demonstrated a substantial reduction in bacterial adhesion after 4 h of incubation in bacterial suspension. The modified gauze suppressed biofilm formation, achieving ~83% reduction in viable bacterial count as compared to unmodified CG after 48 h of incubation in the bacterial suspension. In addition, the modified CG also showed good breathability, wettability and moisture retention properties. The results suggest a promising approach of transforming inert CG into a potential fouling-resistant wound dressing for the management of wound infections. [ABSTRACT FROM AUTHOR]

The influence of cobalt and cobalt–manganese oxide coating thickness on its ability to be a good diffusion barrier against Cr outward diffusion was investigated for stainless steel interconnects (AISI 441) of a solid oxide cell (SOC). The coatings were all synthesized using a DLI-MOCVD (Direct Liquid Injection-Metal Oxide Chemical Vapor Deposition) hot wall reactor. The study shows that a minimum cobalt oxide thickness of 300 nm was needed to be a good diffusion barrier against Cr for the 500-h exposure test. This observation was linked to the Mn concentration reached in the cobalt spinel during exposure. Indeed, during exposure at high temperature, Mn diffused from the substrate into the cobalt coating and transformed cobalt spinel into Co-Mn spinel. Whereas pure cobalt spinel was a good Cr diffusion barrier, cobalt-manganese spinel, Co3-xMnxO4, was not when x > 2. The thickness of the cobalt coatings must be chosen so that the Mn quantity coming into it from diffusion from the substrate does not degrade the protectiveness of the coating. [ABSTRACT FROM AUTHOR]

The oxidation of a titanium (Ti)-modified Mo-Si-B alloy designed for aerospace applications was investigated. Test samples were produced using arc melting and laser powder bed fusion (LPBF) additive manufacturing methods. To address high-temperature oxidation, a three-step coating strategy was employed, comprising a Mo precoat, Si and B co-deposition, and a conditioning step for the formation of a self-healing coating. The study evaluates the oxidation resistance of both uncoated and coated Mo-Si-B-Ti alloys at temperatures ranging from 1100 to 1300 °C. Uncoated alloys exhibited catastrophic mass loss within 10 hours at temperatures between 800 and 1300 °C. In contrast, the coated samples demonstrated minimal mass loss at 1300 °C after 50 hours, with only minor mass gain observed under cyclic thermal loading after 300 cycles. Microstructural analysis revealed distinct differences between arc-melted and LPBF samples, with the latter displaying an ultrafine dendritic microstructure. The applied coating effectively prevented oxygen diffusion into the substrate, even at elevated temperatures, showcasing its protective capabilities. During cyclic tests, the coating exhibited a self-healing mechanism, with cracks filled with borosilica contributing to prolonged environmental resistance. [ABSTRACT FROM AUTHOR]

The performance of solid oxide electrolyzer cells (SOEC) can be improved through the development of coatings applied to the surface of ferritic steel interconnects in view of mitigating chromium evaporation and reducing the growth rate of low conductive oxides in oxidizing environments. This work investigated the oxidation and area specific resistance (ASR) of two electrodeposited nickel coatings on preoxidized and non-preoxidized AISI 441 ferritic stainless steel substrates. The nickel coating effectively restricted the outward diffusion of chromium after 100 h of exposure at 700 °C in air but led to nickel/iron interdiffusion between the substrate and coating forming an iron-nickel-rich spinel on the surface, with NiO underneath and Cr2O3 at the coating-substrate interface and at the coating grain boundaries. The application of a LSM ((La0.80Sr0.20)0.95MnO3−x) coating on top of the Ni electrodeposited coatings resulted in the same type of oxides but the oxidation kinetics were slower. Interdiffusion continued with the exposure at 700 °C for 2400 h resulting in the growth of a thick iron-rich oxide layer on top of Cr2O3, steadily raising the interconnect ASR to 25 mΩ cm2. The addition of a preoxidation step before the electrodeposit of nickel helped to limit iron-nickel interdiffusion, leading to the formation of a thicker NiO layer on a Cr2O3 layer between substrate and coating. While the ASR was higher than without preoxidation at the beginning of the test, it stabilized at about 33 mΩ cm2 after 1750 h. Despite displaying a higher electrical resistance, the coatings effectively limited the outward chromium diffusion throughout exposure compared to the bare substrate. [ABSTRACT FROM AUTHOR]

In recent years, significant research has been carried out for a long time on improving the mechanical properties of the surfaces of metallic materials with various surface coating methods. This study was conducted to investigate in detail the microstructure and wear behaviour properties of the coating, made by the hot press sintering method (HPSM), on AlZn5.5MgCu alloy. The coating layer was hot pressed for 25 min with Al+5%vol. SiC powder particles at sintering temperatures of 580, 600, and 620°C under 120 MPa pressure. The microstructure of the coating produced at different sintering temperatures and the microstructures of the interface region and the substrate were analysed by optical microscopy (OM), Scanning Electron Microscopy and Energy Dispersive Spectroscopy (SEM-EDS), and X-ray diffraction (XRD). Microhardness values were also measured on the coating layer and the linear reciprocating wear test was applied. The microstructure results indicated a homogeneous distribution of SiC particles in the Al powder. Also, the mass loss reduced and the microhardness values significantly raised due to the increase in sintering temperature values. It was seen that with this method, the coating thickness amount could be made in accordance with the desired value. [ABSTRACT FROM AUTHOR]

Coatings serve as ideal protective films for mechanical systems, providing dependable as well as efficient lubrication because of their unique structure along with outstanding tribological characteristics. Inspired by the "bricks-and-mortar" structure, we prepared layered graphene oxide (GO) composite finishes strengthened with polyvinyl alcohol (PVA) and borax. Our study demonstrates that the tribological properties of the GO-based coating on 304 stainless steel (SS304) are potentially greatly affected through PVA, GO, and annealing. By optimizing the composition, we achieved the PVA40 wt%/GO0.01 wt%/borax composite coating, which exhibited the lowest average coefficient of friction (COF) of 0.021±0.003 (a 97.86% reduction compared to control SS304) with minimal wear and abrasion even in a water environment. We found that the enhanced mechanical characteristics as well as elastic recovery within the coating were attributed to the hydrogen bonds and cross-linking between PVA and borax, which led to stress distribution. Reduced friction was further aided by the formation of a hydrated layer at the friction interface. As a result, the coating demonstrated remarkable durability, maintaining a low COF during long sliding distances (576 m, 28,800 cycles, significantly longer than previously reported) without breaking. [ABSTRACT FROM AUTHOR]

Chromatogeny is a hydrophobization technique with fatty acid chloride without solvent that confers an improved barrier to water and water vapour, thanks to a technology that can be implemented on an industrial scale and adapted to any hydroxylated substrate, including cellulosic materials. In this work, a chromatogenically modified polyvinyl alcohol (PVA) coating layer was used as a high oxygen barrier material and as a model for hydroxylated polymers, including microfibrillated cellulose coating. Multiple passes can be applied to the coated layer to improve grafting densities. However, little is known about the molecular mechanisms and distribution of the reagent in the coated layer or whether it also modifies the board. In this work, we have demonstrated that the modification proceeds from the surface to the interior of the PVA layer by developing an imaging technique based on labelling with osmium tetroxide (OsO4) of the double bond of an oleyl acyl chloride used as an unsaturated hydrophobizing agent. The result is a brilliant marking of the modified PVA layer strictly limited to the top surface, as revealed by SEM images. Calculations based on simple assumptions about volume expansion due to modification were compared with experimental data, i.e. measurements of the thickness of the grafted layers. The results showed that, under our experimental conditions, the reagent penetrates a zone strictly limited to the upper part of the PVA layer and never reaches the board. Moreover, the second pass does not significantly increase the reagent's penetration depth, but does significantly increase the hydrophobicity of the grafted material, as shown by the Cobb measurements. The cardboard remains intact in all the experimental situations explored on a pilot scale. The techniques developed will be transferred to the emergence of a cellulose-based barrier coating with cellulose microfibril films. [ABSTRACT FROM AUTHOR]

The work presents the results of the corrosion resistance study of composite coatings obtained by cold spraying of the aluminum and boron carbide powder mixture on the surface of 08Cr18Ni10Ti austenitic steel. Their chemical and phase compositions, macro- and microstructure, as well as the effect of subsequent heat treatment are analyzed. It is shown that the corrosion of coatings in a 2% boric acid solution at 60 °C is accompanied by an increase in the sample mass and the formation of an aluminum oxide layer. The minimum mass change was observed in case of the coating heat treated at 400 °C, while an increase in heat treatment temperature leads to the intensification of corrosion destruction. [ABSTRACT FROM AUTHOR]

As an important turbocharging equipment, hydraulic pumps are prone to internal wear and corrosion problems. In order to improve its friction and wear performance, a ceramic coating strengthening scheme based on laser cladding technology was proposed. The roughness, thickness, width, hardness, and residual stress of the coating under different laser powers and scanning rates were measured, and the effect of process parameters on the coating structure was determined to ensure the optimal basic mechanical properties of the coating. Under the experimental conditions of 10–30 N pressure and 10–20 mm/s lubricated friction velocity, high cycle tribological tests were conducted, and the changes in average friction coefficient, wear amount, and surface wear mechanism were compared and analyzed. To verify the impact of reinforced coatings on corrosive environments, friction and wear tests were conducted in hydraulic oil environment with a pH of 6.4 and particle impurity content of approximately 5 %. Through electron microscopy, the friction morphology was observed and the wear mechanism was analyzed. In order to study the effects of different overloads (including temperature and pressure loads) on friction damage, overload friction damage analysis was conducted under low cycle fatigue loading conditions. The Rtec friction machine was applied, and the test temperature and pressure were set at 400 °C, 500 °C, 750 MPa, and 1000 MPa, respectively. The coating sample speed was set to 500 r/min and the slip rate is set to 5 %. Each sample was worn for 4 cycles under different pressures, with each cycle worn for 1 hour, then the surface roughness morphology and micro wear morphology were obtained. The research results indicate that the friction stability, wear resistance, and hardness of the coating have significantly improved, and it has stronger adaptability to hard or sharp materials, making it very suitable for the working environment of hydraulic pumps. [ABSTRACT FROM AUTHOR]

This study aims to create fire-resistant performance of polyurethane (PU)-coated textiles by adding wool powder as a flame retardant on both cotton and polyester fabrics. A flame-retardant surface was therefore developed by coating the fabrics with a mixture of PU and wool powder and characterised by using Fourier transform infrared spectroscopy and scanning electron microscopy. The experimental results demonstrated that with a coating thickness of 0.5 mm onwards, an improvement in the fire-resistant properties is observed. Unlike fabrics coated only with PU, the addition of wool powder allows the fabrics to resist the flame at 5 and 10 s. Water and air permeability properties of the coated fabrics were also evaluated and show interesting and complementary results. Integration of wool powder as a flame retardant is a promising approach to develop fire-resistant fabrics that can lead to wide applications in fire protection and safety. [ABSTRACT FROM AUTHOR]

The surface modification of electrode active materials has attracted considerable attention as a straightforward approach to enhance properties of lithium-ion batteries. In this study, we present a facile method for preparing surface-modified natural graphite (NG) by uniformly mixing NG with polyvinyl alcohol (PVA) and subsequent carbonization to obtain carbon-coated NG as an anode material for lithium-ion batteries. The optimal performance was achieved when the mass ratio of PVA to NG is 1:5. The carbon-coated NG anode material demonstrated a stable discharge specific capacity of about 400 mAh g−1 and excellent cycle retention (72.8% after 100 cycles at 0.2 C), showing an average capacity of 24% that is higher than that of NG. Furthermore, carbon-coated NG also presented superior rate performance compared with pure NG. The concept of coating NG with PVA-derived carbon proposed in this paper paves the way for innovative high-performance lithium-ion battery anode materials. [ABSTRACT FROM AUTHOR]

Packaging aims first to protect the quality and safety of food. Although synthetic packaging is easy and practical to use, it significantly poses many health and environmental hazards. In this context, the need for environmentally and food-friendly packaging is increasing. Edible coatings with many barrier properties cover the food surface like a blanket. This study evaluated content analyses and research trends on the edible coating of foods. For this goal, a bibliometric network analysis of the studies that included the concepts of "edible packaging", "coating", and "food" together in the abstracts, keywords, and titles of the articles was carried out. Today, with this network analysis method, it is easier to summarize innovations in edible coating technology and their applicability to foods in a detailed and understandable way. Between 2016 and 2023, bibliometric data consisting of 2131 studies were processed VOSviewer program using the network analysis method. Results revealed that China is the leading country in coatings studies, followed by India. The study shows which foods and methods the coatings are applied. [ABSTRACT FROM AUTHOR]

So far, the sol-gel process has been available to prepare precursor gels of bioactive glasses with various compositions. In this report, we described a novel coating method of bioactive gels on a titanium substrate where the sol-gel transition is controlled by applying external electric fields. The application of a constant current of 10 mA/cm2 in an acidic sol containing pre-hydrolyzed tetraethoxysilane, calcium nitrate, and ammonium dihydrogen phosphate led to the deposition of gels on the titanium cathodes due to the generation of OH– by water electrolysis as a catalyst of the sol-gel transition. The obtained gels, which were characterized to be amorphous and consisted of Si, Ca, and P, covered the titanium substrates as a coating. The bioactivity of the gels deposited was confirmed by soaking in a simulated body fluid (SBF) up to 7 days, suggesting that the electrochemically assisted sol-gel process is promising for providing bioactive coatings on metallic implants. Highlights: The electrochemically assisted sol-gel processing successfully led to the deposition of bioactive gel coating on titanium substrates. The gels were amorphous and consisted of Si, Ca, and P, characterized by XRD, FT-IR, SEM, and EDX. The gels successfully formed apatite on them in a simulated body fluid (SBF) for at least 1 day. The novel and straightforward electrochemical method in providing bioactivity is promising for surface modification of metallic implants. [ABSTRACT FROM AUTHOR]

In this study, the tribological characteristics of TiN, AlTiN, and AlTiCrN coatings sliding against a SUS420J1 stainless steel pin were investigated in atmospheric and vacuum environments. The coatings were deposited on SUS440C substrates using the arc-physical vapor deposition technique. The friction and wear behavior of the coatings were evaluated based on the systematic analyses of the friction coefficient data as well as the physical and chemical state of the wear track. The results revealed that the friction coefficients of the SUS440C specimen and AlTiCrN coatings increased, whereas those of the TiN and AlTiN coatings decreased when the environment was changed from atmospheric to vacuum. It was confirmed that the formation of an oxide layer and adsorption of oxides on the surface were dominant factors that influenced the tribological behavior in the atmospheric environment. On the other hand, the compatibility, oxidation inhibition, and droplets of the surface mainly affected the frictional characteristics in the vacuum environment. The results of this work are expected to aid in the selection of proper coating materials for tribological systems operating in a vacuum. [ABSTRACT FROM AUTHOR]

Nickel-PolyTetraFluoroEthylene (Ni-PTFE) composite coatings were prepared from a watts-type nickel plating bath by varying process parameters in this study. The considered input process variables were current density, potential of hydrogen range, bath temperature, PTFE bath concentration, and stirrer speed. Experiments systematically analyzed their effects on outcomes. The responses measured in the experiments included the surface roughness, mass of deposit, and coating thickness of the coated samples. Scanning electron microscope and microstructure examinations analyzed Ni-PTFE deposition in specimens from mild steel plates. Additionally, an adaptive neural fuzzy inference system model was developed to predict the surface roughness, mass of deposit, and coating thickness of the coated samples. The model showed high accuracy in predicting parameters, closely matching experimental data. [ABSTRACT FROM AUTHOR]

In light of the challenges associated with catalyst separation and recovery, as well as the low production efficiency resulting from intermittent operation for titanium silicalite-1 (TS-1) catalyzed phenol hydroxylation to dihydroxybenzene in the slurry bed, researchers keep on exploring the use of a continuous fixed bed to replace the slurry bed process in recent years. This study focuses on preparing a TS-1 coated structured catalyst on SiC foam, which exhibits significant process intensification in performance. We investigated the kinetics of this structured catalyst and compared it with those of extruded TS-1 catalyst; the dynamic equations of the two catalysts were obtained. It was observed that both catalysts followed E-R adsorption mechanism model, with an effective internal diffusion factor ratio between structured and extruded TS-1 of approximately 7.71. It was confirmed that the foamed SiC-based structured TS-1 catalyst exhibited significant improvements in phenol hydroxylation in fixed-bed reactor due to its well-developed pore structure, good thermal conductivity, excellent internal mass transfer performance, and short reactant diffusion distance, leading to higher utilization efficiency of active components. This finding also provides a foundation for designing and developing phenol hydroxylation processes in fixed-bed using structured catalysts through computational fluid dynamics calculations. [ABSTRACT FROM AUTHOR]

Purpose: Nanoparticles (NPs) as radiosensitizers present a promising strategy for enhancing radiotherapy effectiveness, but their potential is significantly influenced by the properties of their surface coating, which can impact treatment outcomes. Most Monte Carlo studies have focused on metallic NPs without considering the impact of coating layers on radiosensitization. In this study, we aim to assess both the physical and radiobiological effects of nanoparticle coatings in nanoparticle-based radiation therapy. Materials and methods: In this simulation study, we used Geant4 Monte Carlo (MC) toolkit (v10.07.p02) and simulated the bismuth, gold, iridium and gadolinium NPs coated with polyethylene glycol (PEG-400: Density: 1.13 g/cm³, Molar mass: 380–420 g/mol) as radiosensitizer for photon beams of 30, 60 and 100 keV. Secondary electron number and reactive oxygen species enhancement factor were estimated. Also, dose enhancement factor (DEF) was determined in spherical shells with logarithmic scale thickness from the nanoparticle surface to 4 mm. Results: Secondary electron emission was highest at 30 keV for gold, bismuth, and iridium NPs, while gadolinium NPs peaked at 60 keV. Coating reduced electron emissions across all energies, with thicker coatings leading to a more significant decrease. DEF values declined with increasing radial distance from the NP surface and were lower with thicker coatings. For gadolinium NPs, DEF behavior differed due to K-edge energy effects. Reactive species generation varied, showing maximum production at 30 keV for gold, bismuth, and iridium NPs, while gadolinium NPs showed peak activity at 60 keV. PEG coatings enhanced reactive species formation at 100 keV. Conclusion: The findings indicate that the coating layer thickness and material not only influence the emission of secondary particles and DEF but also affect the generation of reactive species from water radiolysis. Specifically, thicker coatings reduce secondary particle emission and DEF, while PEG coatings demonstrate a dual behavior, offering both protective and enhancing effects depending on photon energy. These insights underscore the importance of optimizing NP design and coating in future studies to maximize therapeutic efficacy in nanoparticle-based radiation therapy. [ABSTRACT FROM AUTHOR]

The Box-Behnken design (B.B.D.) experiment was used to optimise the extraction parameters of Swietenia mahogany Jacq. (L) bark, and the chemical constituents responsible for the antibacterial property were examined. Independent variables including time, temperature, and concentration were optimised to produce the maximum yield percentage. The quadratic model was created using the dependent variable as yield percentage (Y%), and three independent variables such as temperature (40 to 70 oC), extraction duration (1 to 2 h), and concentration (acetone and plant extract ratio) (4 to 10%). The yield of 17 sample runs was coated on cotton fabric to measure the antibacterial activity by the Kirby-Bauer disc diffusion test method. The maximum extract yield (23.25%) was found in the study's results with the independent parameters of temperature (55°C), extraction time (2h), and concentration (4%). Chemical analysis using ATR-FTIR was performed to identify significant chemical bonding groups in the extract at maximum yield conditions. The process parameters were used to create a quadratic regression model, and it was found that all the model's chosen components were significant. The effect of concentration on extraction yield is most significant among the three factors. The antibacterial activity of all 17 extracts coated on cotton fabric revealed mild to strong activity against four test organisms, and Gram-positive strains showed stronger activity than the Gram-negative strains. The higher yield % (23.25) was found in the sample run 10, and the antibacterial result of the sample 10 performed higher ZOI (zone of inhibition) value of 20 mm against Gram-positive (Staphylococcus aureus and Bacillus subtilis) strains and 18mm and 13 mm against Gram-negative strains (Escherichia coli and Pseudomonas aeruginosa) respectively. It is now known that Swietenia mahogany Jacq. (L) bark extract is a suitable surface active agent on textile for the production of medical and healthcare textiles. [ABSTRACT FROM AUTHOR]

In this work, Al9.9Co18.18Cr18.18Fe18.18Mo18.18Ni18.18 (at.%) high-entropy alloy was laser-cladded on the surface of H13 steel to extend the operating temperature range. Due to the dilution of substrate, coating with a composition of Al3.63Co10.58Cr13.41Fe51.28Mo12.15Ni8.95 (at.%) was achieved, which was a multi-phase system composed of FCC + BCC + σ + μ. Moreover, the phase transformation and the solidification behavior of the coating were studied in detail by utilizing phase diagram calculation. Oxidation resistance of the coating was also investigated and compared with that of H13 steel over temperature range of 600-800 °C. Both the coating and H13 steel show excellent oxidation resistance at 600 °C. After holding at 700 °C and 800 °C, the oxidation rate (the increment in oxide layer thickness per unit of time) of the coating is significantly smaller than that of H13 steel. It indicates that Al3.63Co10.58Cr13.41Fe51.28Mo12.15Ni8.95 coating has an advantage over H13 steel when oxidized over the temperature range of 700-800 °C. Based on the research in this work, the service temperature of H13 steel can be effectively extended by the Al3.63Co10.58Cr13.41Fe51.28Mo12.15Ni8.95 coating. [ABSTRACT FROM AUTHOR]

Systems theory can be used not only to assess the existing state of engineering and technological systems, but also to forecast their development. This approach implies the creation of a generalized model of the object under study taking the existing connections between its individual components into account, along with an analysis of the energetic, material, and informational resources inherent in this object. This allows selection of the most optimal solution for improving the technological system under analysis from a variety of possible options. Creation of high-entropy compounds of various compositions is an intensively developing direction of modern materials science. Due to their specific chemical composition, such materials may exhibit a unique combination of properties, thereby outperforming other types of compounds. In this work, we study structural and functional interactions in a technological system aimed at obtaining coatings by laser cladding of high-entropy materials, which are represented by the starting powders mixed in a certain proportion. The input and output parameters of the laser cladding process are established. This process is represented in the form of sequential phases, resulting in the formation of a coating on the surface of the product. The coating is characterized by both technological and specific properties, depending on the chemical composition of the starting powder components. A structural and functional scheme describing the process of coating formation from a high-entropy material during laser cladding is proposed. Connections between the input and output process parameters are demonstrated. These connections reflect the formation of specific coating properties in the process of laser cladding as a result of interaction of the powder material with the laser beam. It is noted that structural and functional schemes should be used when simulating technological processes based on mathematical models, taking the occurring transformations of substances into account. [ABSTRACT FROM AUTHOR]

The presence of iron (Fe) has been found to favor power generation in microbial fuel cells (MFCs). To achieve long-term power production in MFCs, it is crucial to effectively tailor the release of Fe ions over extended operating periods. In this study, we developed a composite anode (A/IF) by coating iron foam with cellulose-based aerogel. The concentration of Fe ions in the anode solution of A/IF anode reaches 0.280 μg/mL (Fe2+ vs. Fe3+ = 61%:39%) after 720 h of aseptic primary cell operation. This value was significantly higher than that (0.198 μg/mL, Fe2+ vs. Fe3+ = 92%:8%) on uncoated iron foam (IF), indicating a continuous release of Fe ions over long-term operation. Notably, the resulting MFCs hybrid cell exhibited a 23% reduction in Fe ion concentration (compared to a 47% reduction for the IF anode) during the sixth testing cycle (600–720 h). It achieved a high-power density of 301 ± 55 mW/m2 at 720 h, which was 2.62 times higher than that of the IF anode during the same period. Furthermore, a sedimentary microbial fuel cell (SMFCs) was constructed in a marine environment, and the A/IF anode demonstrated a power density of 103 ± 3 mW/m2 at 3240 h, representing a 75% improvement over the IF anode. These findings elucidate the significant enhancement in long-term power production performance of MFCs achieved through effective tailoring of Fe ions release during operation. [ABSTRACT FROM AUTHOR]

Lithium-sulfur batteries have become a research hotspot in the field of energy storage due to their high capacity and low cost. However, lithium metal anodes' short cycle life and safety performance severely limit their commercial application. Here, we used an "in situ" method to form a stable artificial solid electrolyte interface on the surface of the metal lithium, which can control the electrochemical behavior of the interface between the lithium metal and the electrolyte and inhibit the growth of lithium dendrites. The electrochemical performance of lithium-sulfur batteries with protected lithium anode is greatly enhanced. The discharge capacity remains at 1519.6 mAhg−1 after 100 cycles at 0.1 C. In addition, the rate capability of lithium-sulfur batteries is also significantly improved, delivering a reversible capacity of 685.7 mAh g−1 at 0.5 C. [ABSTRACT FROM AUTHOR]

Concrete is the second most widely consumed material across the globe after water and it is the most utilized building material. However, microbial contamination and corresponding degradation in concrete structures reduce its life span. This also imposes a financial burden as well as a threat to public health. The major scientific question posed in this research is, "Can we utilize turmeric as an alternate coating to introduce antibacterial properties in concrete structures?". Our obtained results show that turmeric coating in concrete results in up to ~ 68% antibacterial efficacy against Staphylococcus aureus (S. aureus) without compromising the mechanical properties. [ABSTRACT FROM AUTHOR]

Cold spray technology is a multifaceted, environmentally friendly, and very promising method utilised for the aim of applying coatings onto complex geometries. This research examines several challenges pertaining to cold spray coating that have the potential to restrict its practical application. The application of this methodology enhances the depth of understanding of the fundamental process, allows for precise control of coating properties, and supports the refinement of cold spray treatments. Furthermore, it exhibits the supplementary benefit of being environmentally friendly because of its eradication of hazardous emissions and utilisation of flame. Moreover, the application of gas-turbine-driven cold spray equipment provides improved accuracy in controlling the coating thickness. Additionally, it has the capability to be combined with other methods such as laser cladding and thermal spraying to enhance its overall efficiency. [ABSTRACT FROM AUTHOR]

The atmospheric corrosion monitoring (ACM) technique has been widely employed to track the real-time corrosion behavior of metal materials. However, limited studies have applied ACM to the corrosion protection properties of organic coatings. This study compared a bare epoxy coating with one containing zinc phosphate corrosion inhibitors, both applied on ACM sensors, to observe their corrosion protection properties over time. Coatings with artificial damage via scratches were exposed to immersion and alternating dry and wet environments, which allowed for monitoring galvanic corrosion currents in real-time. Throughout the corrosion tests, the ACM currents of the zinc phosphate/epoxy coating were considerably lower than those of the blank epoxy coating. The trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface analysis. This alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic coatings. Compared with the blank epoxy coating, the zinc phosphate/epoxy coating showed much-decreased ACM current values that confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating. [ABSTRACT FROM AUTHOR]

Plasma spray is a promising technology for surface protection and modification in many industrial application fields. However, the low adhesive or cohesive strength of the plasma sprayed coatings limited their further application. The cohesive strength was enhanced 115% ultra-sonicating the substrate during the plasma spraying process of Ni-10wt.%Al coatings. With the increase of power density from 0 to 1.32 W/cm2, the porosity, residual stress and strain were all decreased. However, when the power was further increased to 2.20 W/cm2, the porosity, residual stress and strain were all increased. Ultrasonic energy and the ultrasonic effects of acoustic pressure, acoustic streaming, heat effect, and cavitation effect would affect the physical processes of wetting, filling and solidification of the molten droplets during the plasma spraying process, affecting the microstructure and cohesive strength of the plasma sprayed coatings. The ultrasonic energy and ultrasonic effects which are affected by the ultrasonic power density affecting the fundamental physical processes is the key to enhance the cohesive strength of the plasma sprayed coatings. [ABSTRACT FROM AUTHOR]

Titanium implants, which are widely used in orthopedic implant applications, require surface treatments due to their low osteoinduction properties and the risk of postoperative infection. In this study, apatite wollastonite (AW)-based coatings with chitosan (CHI) and silver (Ag) added were applied to the titanium surface using dip coating and drop casting techniques. The obtained coating surfaces were characterized by FESEM, EDS, XRD, FTIR, and TGA–DSC. Biomineralization behaviors were examined by immersing the resulting coatings in simulated body fluid with pH 7.2–7.4. The antibacterial activities of the coatings obtained using S. aureus and E. coli bacterial colonies were examined. Following the successful coating of AW nanoparticles on the Ag and CHI implant substrate, the Ca/P ratio of the coated surface was obtained as 1.4–1.92% after the biomineralization process performed at 37° for 7 days. Ag particles were successfully distributed homogeneously with a 40–50-nm diameter in Ag-doped coatings. It was concluded that the successfully produced composite coating with bioactive and antibacterial properties is a suitable candidate material for metallic implant surfaces. [ABSTRACT FROM AUTHOR]

In this study, we examine the combination of flexible textiles and electrodes to develop electronic textiles (e-textiles). We present a facile fabrication process using printing and coating conductive electrodes. Innovative textiles, which have evolved primarily through the integration of textile and electronic elements, have developed into e-textiles capable of performing high-dimensional tasks. For practical use of e-textiles, however, they should be compatible with various textiles, economical production, and suitable for mass production. In this study, silver ink-carbon nanotubes are used to screen-print electrodes, a key element of e-textile. We verify four types of spandex textiles and analyze whether ink-based electrodes are stably printed on the textile surfaces. As a post-process, 3D printing mold coating is invited to invent durable and water-repellent electrodes. The fabricated e-textile proves its practicality using a washing test. Additionally, electrical measurements under mechanical bending reveal a variety of potential applications based on their properties. As a result, the electrodes of e-textile have an initial electrical resistance of approximately 10 Ω. Polymer coating enhances the reliability of e-textiles. Washing tests and repeated bending deformation demonstrate that they help the coating maintain its electrical conductivity. On the other hand, electrodes without coating lose their electrical capabilities. This study proposes functional materials and reliable manufacturing methods that are beneficial for e-textile production. Accordingly, we present the diversification and potential of the smart textile industry, such as IoT sportswear, medical healthcare clothing, hazardous work detection clothing, and space exploration clothing, which are examples of applications based on e-textile materials and manufacturing technology. [ABSTRACT FROM AUTHOR]

This paper solves the dynamic contact problem when a rigid flat punch indents into an exponentially graded (FG) viscoelastic coated homogeneous half-plane. A harmonic vertical force is applied to the FG coating, and the solution is obtained for the stress and displacement for both the FG viscoelastic coating and the half-plane using the Helmholtz functions and the Fourier integral transform technique. By applying specific boundary conditions, the contact mechanics problem is converted into a singular integral equation of the first kind. This equation is then solved numerically using the Gauss-Chebyshev integration formulas. The analysis provides detailed insights into how various parameters—such as external excitation frequency, loss factor ratio, Young's modulus ratio, density ratio, Poisson's ratio, indentation load, and punch length—affect the dynamic contact stress and dynamic in-plane stress. [ABSTRACT FROM AUTHOR]

Lignosulphonate-based azo pigments are synthesized by functionalizing industrial waste lignosulphonate material through a diazo coupling reaction. It has dispersion and metal surface protection function by coating. Aniline, 4,4′-bis(4-aminophenoxy) biphenyl (BAP-Biphenyl), and o-dianisidine were used to synthesize three lignosulphonate-based azo pigments. 1H-NMR, FT-IR, HRMS, and UV spectroscopic methods confirm the pigment formation through the diazo coupling reaction of lignosulphonate and products. By using TGA and DSC analysis, the thermal behaviour of azo pigments was examined. Successive increase in mass also suggests successful diazo coupling reaction. The light scattering technique gives particle size of azo pigments for aniline-azo-LS, BAP-Biphenyl-azo-LS and o-dianisidine-azo-LS were found to be 1578, 2387, and 1917 nm, respectively. Additionally, the negative zeta potential was noticed indicating the pigments' dispersion ability. This dispersible ability was utilized for paint formulation, and chemical resistance of metal coating was observed. The formulation has good mechanical stability, and TGA suggests the thermal stability over 200 °C. This lignin-based functional pigment will find new forms of an environmentally friendly and sustainable method for a cleaner utilization of lignin in metal coatings. [ABSTRACT FROM AUTHOR]

Iron scrap is one of the substances rejected in large quantities of by-products from the steel industrial sector. In this work, waste cellulosic fibers and iron shavings were used as reinforcement and abrasive particles, respectively. Two methods of the synthesis of the hybrid composites were applied namely spraying and coating. Different analytical techniques of characterization, i.e., Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA/DTG), and energy-dispersive X-ray (EDX), were used to analyze the studied samples. The morphology of the abrasives displayed the presence of spherical grains on the surface with a diameter ranging from 100 to 200 µm. In the spraying process, the surface was characterized by the presence of hollows, bumps, and small empty areas. For the coating process, the fibers of the reinforcement and some drops of resins were visible on the surface of the abrasives. The EDX analysis suggested that the abrading action of the composite surface might be done by tearing off the iron grains. The properties of the matrices, process considered, size of the grains, and their distribution were found to be the principal parameters governing the abrasive process. As the particle size increases, the surface becomes rougher, allowing for more scraping of the materials surfaces. [ABSTRACT FROM AUTHOR]

The results of experiments aimed at studying the dependence of the adhesion strength of a coating deposited onto a screw-shaped surface of a part through plasma spraying depending on technological spraying modes. Results of correlation and regression analyzes are presented. [ABSTRACT FROM AUTHOR]

Acrylic substrates made from polymethylmethacrylate (PMMA) are anticipated to develop craze and scratches owing to their continual wear. In this study, novel silane modified acrylic resin based organic-inorganic hybrid coating materials have been formulated to provide protection to PMMA substrates against wear. Varied amounts (5, 10 and 15 % wt./wt.) of tetraethoxysilane (TEOS) were added to the acrylic resin solution (containing xylene and 10% ammonia) and the resultant hybrid coating materials were then coated on PMMA substrates through the dip coating method. The hybrid coating materials were transformed into hard coats upon hydrolysis, condensation and cross-linking. The coated samples were characterized to assess the effect of TEOS addition on optical and mechanical properties as well as abrasion resistance of the hybrid coatings. Hardness, stiffness and reduced elastic modulus of the dry coatings obtained through the instrumented indentation technique were observed to increase (up to ca. 56%, 28% and 65% respectively) whereas their viscous nature and plasticity decreased with the addition of TEOS. The hybrid coatings also demonstrated improved wet abrasion resistance which augurs well with their physico-mechanical properties. These observations can be ascribed to the combined contributions of organic-inorganic phase interactions in the coating materials via hydrogen bonding and the formation of cross-linked silica structures as observed through infrared spectroscopy and microscopy. [ABSTRACT FROM AUTHOR]

The protection of boiler tubes against erosion caused by fly ash is essential for maintaining boiler efficiency. This study proposes a metallic coating based on Fe–Cr-B-Mn, applied using the electric arc thermal spray technique, as an alternative for protecting the most impacted areas of boiler tubes from ash erosion. The impact of different surface finishes, obtained through grinding, on the erosive wear resistance of the coating was analyzed. The electric arc thermal spray was performed manually at an angle between the gun and the plate of 90 degrees, in atmospheric air. The coating's surface roughness (Ra) was measured with a rugosimeter, in 2 preferential directions, and was found to have values between 11 and 17 μm. Grinding was chosen as the machining process due to its efficiency in finishing thermally sprayed surfaces. Three conditions were analyzed: as-coated (Ra = 13.08 µm), the intermediate surface finish (Ra = 2.495 µm), and the surface fine finish (Ra = 0.486 µm). Samples in all conditions were submitted to erosion tests according to ASTM G76, using alumina blasting. The surface was examined by scanning electron microscopy (SEM). The morphology of machining scars demonstrated a brittle failure mode of material removal during grinding. Additionally, the cross-section was investigated using optical microscopy. Abrasive wear tests presented average erosion rates of 3.038 × 10−5 g/s, 2.23574 × 10−5 g/s, 2.77325 × 10−5 g/s for fine, intermediate, and as-coated finishes, respectively. The results guided the optimized selection of materials and processes to protect boiler tubes from fly ash impact. [ABSTRACT FROM AUTHOR]

Polymethyl methacrylate (PMMA) is an important thermoplastic polymer and a versatile lithographic resist. However, the low heat resistance and low dry-etch resistance seriously restricts the application of PMMA in high-end devices and advanced nanolithography. Herein, methyl methacrylate (MMA) was copolymerized with two comonomers 1-adamantyl methacrylate (AdMA) and 1-acryloyloxy-3-hydroxyadamantane (HAdMA), and a series of copolymers P(AdMA-co-MMA) and P(HAdMA-co-MMA) with different contents of HAdMA were prepared. The UV–Vis, ellipsometer, DSC, TG, and TG–MS techniques were employed to investigate the effects of adamantyl and hydroxyadamantyl substituents on the optical and thermal properties of PMMA. The introduced hydroxyadamantyl not only significantly enhanced the refractive index, but also maintained the high transparency and low dispersion of PMMA. The glass transition temperature and thermal stability of PMMA were also greatly improved by the hydroxyadamantyl. The initial decomposition temperature of PMMA increased from 160 to about 260 ℃ after introducing 5% HAdMA. HAdMA was more effective than AdMA in improving the optical and thermal properties of PMMA. The novel P(HAdMA-co-MMA) copolymer has overcome the shortcomings of traditional PMMA and is anticipated to significantly broaden its range of applications. [ABSTRACT FROM AUTHOR]

This research investigates how the thermal, electrical, and hydrophobic characteristics of a nanocomposite coating, which includes grape seed essential oil, are affected by the incorporation of silane-treated nanosilica. The main goal of the study is to create an environmentally friendly polymeric coating and evaluate how the inclusion of grape seed oil and nanosilica influences its performance. The nanosilica was silane-treated using 3-Aminopropyletrimethoxysilane and the coating materials were prepared using blend mixing and casting. Numerous characterizations such as mechanical, thermal, dielectric, hydrophobic and fractography were conducted on the coating material in accordance with ASTM standards and significant findings were obtained. The microstructural analysis via scanning electron microscopy indicated that grape seed oil dispersion is uniform and no distinct lumps identified. Further the nanosilica contributed to improved thermal stability of coating material while maintaining lower dielectric constant and water intake properties. The EOS3 composite coating containing 25 vol. % grape seed oil, with 5 vol. % of nanosilica provided the relative permittivity of 2.81, loss factor of 0.064 and thermal conductivity of 0.228 W/mK, which is equal to plain resin indicating the addition of nanosilica maintains lower permittivity and conductivity in-spite of grape seed oil addition. Moreover, the composite coating 'EOS3' provided high stability in thermal properties. Less mass loss of 2.16% with on-set initial decomposition temperature of 334°C were noted for EOS3 composite coating. The contact angle of 'EOS3' composite designation provided 74°, which is reasonably higher on compare with plain resin indicating still the composites are close to hydrophobic range. Finally, EOS2 (25 vol. % grape seed oil + 3 vol. % nanosilica) delivers better mechanical performance with maximum tensile strength of 59MPa. These bio-oil bended and nanosilica toughened vinyl ester based composite coating materials could be used in food packaging, medical industries and protection of metallic and non-metallic substrates for healthy life span with eco-friendliness. [ABSTRACT FROM AUTHOR]

The corrosion resistance of rebars coated with four different cementitious coatings containing nanoparticles of CaCO3, Fe2O3, SiO2 and ZrO2 is reported. The corrosion resistance of nanoparticle-admixed cementitious polymer on rebars in NaCl medium is evaluated using potentiodynamic polarization (PDP) and impressed voltage test (IVT). The corrosion products of coated rebars, without mortar or concrete cover, after immersion in chloride medium were examined using x-ray diffraction (XRD), scanning electron microscopy (SEM) and laser Raman spectroscopy (LRS). The crack initiation time for rebars coated with nanoparticle-admixed cementitious coating in the absence of concrete is significantly higher than uncoated rebars. PDP and IVT results indicate the best coating is CaCO3 coating, and the coating performance followed the trend CaCO3 > SiO2 > ZrO2 > Fe2O3. The results of these studies indicate that the size as well as the distribution of nanoparticles is crucial for the effective pore filling in the cementitious coating. The superior corrosion protection performance of nanoparticle-incorporated coating is attributed to the effective pore-filling capacity and the better physical barrier formed on the rebars. These findings on nanoparticle-admixed cement coated rebars may have important applications in designing high-performance rebar coating with superior corrosion resistance for aggressive conditions. [ABSTRACT FROM AUTHOR]

Wear and corrosion of boiler tubes in coal-based boilers are one of the serious problems. Trying to solve this issue, FeCr alloy with 45%Cr-content coating and Fe-based coating with 13%Cr-content were arc sprayed onto carbon steel substrates to enhance both the wear and corrosion resistance of boiler heat exchanger pipelines. The microstructure, chemical compositions, and phases of the coatings were analyzed using a scanning electron microscopy, energy-dispersive spectrometer, and x-ray diffraction, respectively. The wear resistance of the coatings was assessed at 25 and 300 °C using a ball-on-disk wear tester. The corrosion resistance of the coatings was evaluated based on seawater immersion, electrochemical impedance, and polarization tests. The porosities of FeCr alloy and Fe-based coatings were 4.05 and 5.75%, respectively. The microhardness values of FeCr alloy and Fe-based coatings were 377.50 ± 46.88 HV0.5 and 666.69 ± 57.64 HV0.5, respectively. FeCr alloy coating with lamellar structure was mainly composed of FeCr solid solution phase and a small amount of Cr oxide and Fe3O4 phases, and Fe-based coating was composed of a mixture phase of amorphous and crystalline, and a small amount of Fe3O4 phase. FeCr alloy coating had better wear resistance than Fe-based coating at both 25 and 300 °C. The wear mechanisms of the coatings were also studied. The corrosion resistance of FeCr alloy coating was better than that of Fe-based coating in corrosive solutions. Therefore, FeCr alloy coating can provide better high-temperature wear resistance and anticorrosion performance for boiler heat exchanger piping, compared with Fe-based coating. [ABSTRACT FROM AUTHOR]

Titanium plasma-sprayed (TPS) porous coatings have been used in total hip arthroplasty for decades. They are considered reliable, and very few failure cases have been described so far. This retrieval study described a series of 20 acetabular components—where total or partial debonding occurred during in vivo use and aimed to explain the underlying failure mechanisms. Implants were examined using optical and electron microscopy (SEM), metallographic sections of retrievals were prepared while pathologic samples of periprosthetic tissues were examined for presence of wear debris. Data from metallographic slides indicated that debonding was initiated at free borders of the coating and tended to progress at the interface between the TPS layer and the shell. In some cases, total debonding occurred leading material wear of both the TPS layer and acetabular shell leading to massive release of metallic debris and accelerated polyethylene wear in third body mechanism. SEM examination demonstrated that splats forming the TPS layer exhibited features suggesting a high temperature gradient between the plasma sprayed layer and the substrate material existed, leading to porosity of splats and suboptimal bonding strength. This study demonstrated that coating application parameters and certain design features (screw holes, fins) may promote long-term failure due to debonding. Surgeons should be aware of this complication as it is most likely underreported, while manufacturers should consider more rigorous pre-clinical testing as suboptimal coating bonding may result in failures during long-term clinical use. [ABSTRACT FROM AUTHOR]

The paper focuses on magnetron sputtering of the pure calcium target in DC magnetron discharge. The target diameter and thickness are 50 and 3 mm, respectively. Argon and krypton are used as working gases. Continuous and medium frequency discharges are investigated along with the discharge and plasma parameters, including a current–voltage characteristic, mass-to-charge ratio of the plasma composition, ion current, and deposition rate. [ABSTRACT FROM AUTHOR]

Valves are essential parts of piping systems in the oil and gas industry. The failure of a valve due to corrosion is an adverse event with several negative consequences. One of the causes of valve corrosion is material mismatch. A PMI test is conducted as part of the project to verify the material of valves, pipes, joints, and pressure vessels. PMI testing of valves has not been studied previously. It is the goal of this study to focus on PMI requirements and case study for valves in order to prevent the negative consequences of its absence, such as corrosion, which can both be costly and unattractive. The purpose of this study is to develop a suitable approach for the development of PMI procedures for industrial valves used in the oil and gas industry. A case study is also described briefly in which the PMI for offshore valves has been forgotten, as well as how the mitigation approach has been implemented. This case study examines the absence of PMI for some dual-plate check valves in an offshore Norwegian project called Edvard Grieg (EG). The project specifications required that 50% PMI be applied to the pressure-retaining parts of a number of these valves made of 22Cr duplex material. The total number of dual-plate check valves is 80. The bodies are made from 22Cr duplex steel. Therefore, 40 valves must be tested for PMI, although only three valves of the 4 inch size and class 150 have already been tested. Consequently, PMI must be conducted on 37 remaining valves during fabrication, which are selected from smaller valve sizes to avoid stopping the fabrication work. According to the PMI results, all of the tested valves were manufactured from 22Cr duplex stainless steel. [ABSTRACT FROM AUTHOR]

In this study, ureidopyrimidinone moieties (UPy), capable of physical crosslinking via quadruple hydrogen bonding, were successfully incorporated into UV-curable polyurethane acrylate prepolymers. First, a hydroxyl-terminated unsaturated ester monomer was synthesized and reacted with isophorone diisocyanate to create a hydroxyl-terminated UV-curable urethane oligomer (U–OH). Then, isocyanate-terminated building blocks (UPy moieties and an acrylate-based photosensitive monomer) were synthesized and used in various ratios to functionalize U–OH for the preparation of a series of UV-curable UPy-containing polyurethane acrylate (PUA) resins. The resulting products were structurally characterized using 1H NMR and FTIR spectroscopy. Furthermore, organic–inorganic hybrid nanocomposites were obtained by introducing silane coupling agents into PUA resins using the sol–gel process. A series of UV-curable UPy-containing PUA coatings and hybrid nanocomposites were prepared, and their synergistic effect on coating properties was investigated. The dynamic mechanical analysis revealed that the Tg of the samples increased with increasing UPy content, although the mechanical properties remained largely unaltered, as shown by the stress–strain test. The studies also demonstrated that the hybrid nanocomposites exhibited higher decomposition temperatures and better thermal stability compared to pure PUAs. All the coatings exhibited good transparency in the visible region. An optical microscope was used to investigate the self-healing property by scratching the plexiglass panels with a razor blade. Among the other samples, the coating with the highest percentage of UPy content exhibited the best self-healing ability after heat treatment at 90 °C for 10 min. [ABSTRACT FROM AUTHOR]

Metallic glasses are a new class of metallic alloys that attract increasing attention in bone implants due to their ultrahigh wear resistance and hardness, high toughness and superior strength. However, their cytotoxicity and biocorrosion resistance are still under investigation. In this research, the cytotoxicity and biocorrosion resistance of iron-based metallic glass composite coating are explored. To approach real-life conditions, the biocorrosion resistance of the proposed coating in phosphate buffer saline (PBS) is evaluated via immersion test for 30 days followed by an electrochemical corrosion test. Then, human bone cells (MG-63) are cultured on corroded samples and the cell viability is determined using MTT assay, in addition to cell attachment examination. The results revealed the formation of a metallic glass composite layer with 78.76% amorphous content. Additionally, the metallic glass composite demonstrated excellent and stable corrosion resistance in PBS over 30 days compared to the substrate. The MTT assay has shown that the cytotoxicity of iron-based metallic glass composite is within the permitted levels according to ISO 10993–5, Part 5 vol 2009. The cells were well attached to the surface besides, showing a healthy growth after 7 days of culture. These results confirm the in vitro biocompatibility of iron-based metallic glass composite coating for biomedical implant applications. [ABSTRACT FROM AUTHOR]

In this study, the experiment and molecular dynamic simulations were used to show how oxygen plasma etching works on diamond-like carbon (DLC) for micro-texturing. On the experimental side, C–C bonds on the DLC were dissociated by the irradiated oxygen. The physical bombardment of reactive oxygen ions selectively removes the carbon atoms in the unmasked area via the generation and desorption of gaseous carbon monoxide and carbon dioxide molecules. Molecular dynamic simulation exhibits the reactivity of O2 molecules with C atoms in the DLC. The quantity of O2 molecules and the formation of new molecules (CO) were proven in this simulation. [ABSTRACT FROM AUTHOR]

The functionalization of polymeric matrices through graft polymerization offers various advantages by providing new properties, allowing for additional chemical reactions that the matrix alone could not undergo or that would require drastic chemical conditions to occur. In this work, epoxy groups were incorporated through a graft polymer of poly(glycidyl methacrylate), using a prefunctionalization with peroxide groups in the polytetrafluoroethylene matrix through gamma radiation. These peroxide groups were subsequently used as radical chemical initiators in the graft polymerization reaction of glycidyl methacrylate. The graft polymerization reaction was studied based on the absorbed dose, monomer concentration, reaction time, and temperature. [ABSTRACT FROM AUTHOR]

Abstract—The effect of thermal treatment on the microstructure, phase composition, and microhardness of Ni + B4C composite coatings is studied. The coatings are deposited onto the surface of an austenitic steel by cold gas-dynamic spraying. The initial coating is shown to be a nickel matrix containing distributed B4C particles. Thermal treatment causes diffusion processes in the coating, which results in the formation of Ni3B and Ni2B compounds. The average microhardness of the initial coating is 3.4 GPa, and heat treatment results in an increase in the coating microhardness due to the formation of hard nickel borides. [ABSTRACT FROM AUTHOR]

Abstract—The influence of diffusion saturation of steel 20 in the medium of low-melting liquid metal melts of Pb–Bi–Li–Ni–Cu composition on its elemental composition and corrosion resistance is considered in this article. As a result of diffusion saturation, a coating is formed structurally consisting of two zones: surface and transition ones. The surface zone contains 53% Cu, 30% Ni, and 17% Fe. As one approaches the transition zone, a decrease in the concentration of Cu and an increase in the concentration of Ni and Fe are observed. In this case, the transition zone structurally consists of inclusions of Fe in a Ni-based solid solution that did not pass into solid solution. In addition, there is a layer under the coating containing C in a higher concentration than the base material owing to the low solubility of C in solid solutions of the Cu–Ni–Fe system. The coating thickness ranges from 8 to 45 μm depending on the temperature and duration of saturation. It is also found that the resulting coatings can reduce the corrosion rate of samples from 3 to 0.8 mm/year. [ABSTRACT FROM AUTHOR]

AlMoON based solar selective absorption coatings were deposited on stainless steel substrate by magnetron sputtering. The coatings included infrared reflection layer Mo, absorption layer AlMoN, absorption layer AlMoON and antireflection layer AlMoO from bottom to top. The surface of the deposited coatings is flat without obvious defects. The absorptivity and emissivity are 0.896 and 0.09, respectively, and the quality factor is 9.96. After heat treatment at 500 °C-36 h, the surface roughness of the coating increases, a small number of cracks and other defects appear, and the broken part is still attached to the coating surface. A certain degree of element diffusion occurs in the coatings, resulting in the decline of the optical properties of the coatings. The absorptivity and emissivity are 0.883 and 0.131, respectively, the quality factor is 7.06, and the PC value is 0.0335. The coatings do not fail under this condition and have certain thermal stability. [ABSTRACT FROM AUTHOR]

This work presents the modification of the morphological, structural, chemical composition, mechanical, and tribological properties of the TaN film by the Zr addition on two substrates (Ti6Al4V and Si substrates) using DC magnetron co-sputtering. As a result, the TaN film presented a dense morphology and a structure combination of c-TaN and Ta phases, with a preferential (110) plane of the c-Ta phase. Nevertheless, adding Zr changed from denser to columnar morphology and a preferential (111) plane of the c-TaN phase related to the power applied to the Zr Target (PZr). These modifications caused the reduction of the hardness (H) and elastic modulus (E*) of the films, from values of 25.8 GPa of H and 221.5 GPa of E* for the TaN films to 18 GPa of H and 155.5 GPa for the TaZrN film at PZr = 55 W. In the same way, the failure modes and load capacity properties were modified with the addition of Zr to the TaN matrix, from buckling failure mode with LC1 of 8 N for TaN film to Chevron Tension Cracks failure mode with LC1 of 12.5 N for the TaZrN film at PZr = 45 W. Nevertheless, the wear rate decreased with the addition of Zr to TaN matrix, from 0.25 and 0.15 (m3/mN × 10-12) at 1 and 2 N of load for the surfaces coated with the TaN film to 0.12 and 0.08 (m3/mN × 10-12) at the same loads for the surfaces coated with TaZrN film at PZr = 45 W. [ABSTRACT FROM AUTHOR]