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[Display omitted] Evaporation of small water droplets on solids is hindered because surface tension pulls the droplet into a spherical cap that has a small perimeter. Our solution is to coat a solid with a very thin, porous layer into which the droplet flows to create a large-area disk with concomitant high rate of evaporation. We investigate evaporation by varying factors that have not been previously considered: pore size and distribution, contact angle, temperature, and relative humidity (RH). A larger pore size resulted in faster evaporation, which we explain through faster transport within the coating. Even faster evaporation occurred for a bilayer structure with small particles on the air side and larger particles on the solid side. The water advancing contact angle had an insignificant effect in the range from < 10° through to 60°. Our results for different pore sizes, temperature, humidity, and contact angle all collapse onto a single curve when appropriately normalized. This validates an equation that can be used for the evaporation from a homogeneous coating that depends only one empirical factor and the droplet volume. Since the volume is often user-controlled, we envisage that this equation can be used to predict evaporation and guide design of fast-drying coatings. [ABSTRACT FROM AUTHOR]

[Display omitted] Clear aligners undergo rapid stress relaxation in warm, moist oral environments, compromising therapeutic effectiveness and longevity of treatment. To develop an innovative multilayer composite material with improved stability and reduced stress release, we have engineered an innovative coating characterized by the surface aggregation of polydimethylsiloxane (PDMS), which imparts a pronounced hydrophobic effect. In addition, the chemically and physically cross-linked structure of the coating reduces the free volume created by molecular chain rearrangement owing to the presence of water molecules, thereby minimizing water penetration into the coating. Concurrently, the coating's internal structure is enriched with numerous polar functional groups to capture water molecules that penetrate into the inside of the coating. Through combination of these mechanisms, water molecules are effectively sequestered, thereby impeding their penetration into the polyethylene terephthalate glycol (PETG) substrate. The impact of the polydimethylsiloxane content on the triple-action water-resistance mechanisms was thoroughly examined using attenuated total reflection (ATR)-Fourier transform infrared (FTIR), water absorption rate, water swelling rate, and X-ray photoelectron spectroscopy. The low surface energy cross-linked polyurethane coating is applied to the polyethylene terephthalate glycol (PETG) substrate to create a novel composite material with specific mechanical properties and reduced stress relaxation. The composite material remains stable in simulated oral environment with linear swelling rate of 0.58 % upon water absorption. Additionally, the stress release rate of the composite material within 336 h is notably lower (23.64 %) than that of PETG (62.29 %). [ABSTRACT FROM AUTHOR]

The traditional packaging concept has reached its limits when it comes to ensuring the quality of food and extending its shelf life. Compared to traditional packaging materials, food packaging with self-healing function is becoming more and more popular. This is because they can automatically repair the damaged area, restore the original properties and prevent the decline of food quality and loss of nutrients. Materials based on various self-healing mechanisms have been developed and used on a laboratory scale in the form of coatings and films for food packaging. However, more efforts are needed for the commercial application of these new self-healing packaging materials. Understanding the self-healing mechanism of these packaging materials is very important for their commercial application. This article first discusses the self-healing mechanism of different packaging materials and compares the self-healing efficiency of self-healing materials under different conditions. Then, the application potential of self-healing coatings and films in the food industry is systematically analyzed. Finally, we give an outlook on the application of self-healing materials in the field of food packaging. [ABSTRACT FROM AUTHOR]

Self‐cleaning hydrophobic films were developed using polyhydroxybutyrate (PHB), enhanced with titanium dioxide (TiO2), bismuth oxyiodide (BiOI), and a BiOI/α‐Fe2O3 heterojunction. This is the first study to analyze the photoactivity of BiOI and BiOI/α‐Fe2O3 immobilized into PHB. Alternative solvents for dissolving PHB were investigated. Additionally, formation methods such as casting in Petri dishes, as well as controlled thickness casting through non‐solvent‐induced phase separation (NIPS), and evaporation‐induced phase separation (EIPS), were employed and compared. Despite differing morphologies, both NIPS and EIPS films exhibited similar photocatalytic activity, suggesting that only the catalyst on the external surface of the film is active. The highest pseudo first‐order apparent kinetic constant (0.1468 ± 0.0015 min−1 g−1) was found in films with the lowest polymer and catalyst concentrations analyzed (5% wPHB/wCHCl3 and 3% wTiO2/wPHB). A double‐layer film preparation method was proposed to enhance photocatalytic activity, resulting in a 70% increase in the kinetic constant (0.2506 ± 0.0019 min−1 g−1). Double‐layer composite films with BiOI and BiOI/α‐Fe2O3 showed photocatalytic activity comparable to TiO2 under UV–visible light. Furthermore, their photocatalytic activity under visible light was confirmed, unlike TiO2, which exhibits a negligible kinetic constant in this wavelength range. [ABSTRACT FROM AUTHOR]

The current study aimed at the preparation of high strength magnesia porcelain. In this study, a coating basic formula of natural ceramic materials of Longyan kaolin (41.94 wt%), burnt talc (52.68 wt%) and Al 2 O 3 (5.38 wt%) were used. In addition, right amount of potassium feldspar and ZnO were added to adjust the coating properties. High strength magnesia porcelain was obtained by the difference of thermal expansion coefficient between coating and substrate. The study focused on the changes in the cross-sectional area ratio and thermal expansion coefficient between the coating and matrix, as well as the effect of adding potassium feldspar and ZnO on the flexural strength of ceramics. Following the addition of 4 wt% ZnO and 13 wt% potassium feldspar, the results indicated a thermal expansion coefficient difference of 3.25 × 10−6/°C and a cross-sectional area ratio of approximately 54.40. The resulting composite ceramics sintered at 1220 °C for 60 min had their flexural strength reached 237.09 ± 26.70 MPa, which was 56.53 % higher than the matrix's flexural strength of 151.70 ± 5.32 MPa. Additionally, a study of the composite ceramics' resistance to thermal shock showed an increase in the critical temperature of decrease in flexural strength from 200 °C to 220 °C. [ABSTRACT FROM AUTHOR]

Refractory metal oxides such as titanium dioxide (TiO 2), tantalum oxide (Ta 2 O 5), and niobium oxide (Nb 2 O 5) coated-titanium and its alloys for medical applications have recently gained significant attention due to their remarkable properties, including high hardness, strong chemical inertness, and excellent biocompatibility. However, comparative studies among them remain scarce. In this study, thin films of Ta 2 O 5 , Nb 2 O 5 , and TiO 2 were deposited on Ti6Al4V titanium alloy using radio frequency sputtering technology. Their properties were comparably evaluated through a series of tests, including scratching, nanoindentation, friction and wear, potentiodynamic polarization, and cell cultivation experiments. The results revealed that all three coatings, with a thickness of approximately 2.6–2.8 μm, exhibited an amorphous columnar growth pattern with dense surfaces resembling cauliflower. The bonding force of the TiO 2 coating exceeds 50 N, which is 26.2 times and 14.5 times greater than that of Ta 2 O 5 and Nb 2 O 5 , respectively. Furthermore, all coated samples demonstrate superior wear resistance, corrosion resistance, and biocompatibility compared to bare Ti6Al4V. Among the coatings, TiO 2 showed the best performance, followed by Ta 2 O 5 , while Nb 2 O 5 exhibited the least favorable performance. These findings revealed the performance differences among the three ceramic coatings on Ti6Al4V samples and offer valuable insights for further research and the selection of coatings to enhance the properties of Ti6Al4V titanium alloy for biomedical applications. [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]

Chloride transport is one of the most serious problems facing reinforced concrete structures, and coatings can effectively block the intrusion of chloride ions. In order to evaluate the resistance of coatings to chloride ion erosion more quickly and accurately, based on the transport mechanism of chloride and water in coated concrete, a two-dimensional mesoscale model of concrete containing coating, aggregate, and matrix was established in this paper. In response to the transport mechanism of chloride ions in coated concrete, a coupled convection–diffusion numerical model considering the binding effect of chloride, temperature effect, and hydration effect is established. The idealized service life conditions of the coating are introduced, and the influence of coating type, coating thickness, and coating service life on the distribution of erosive agents inside the coated concrete is analyzed. After analysis and research, it is recommended that coating concrete exposed to 3.5% NaCl erosion use a film-forming coating with an expected life of more than 10 years and a coating thickness of at least 1.5 mm, preferably chlorinated polyvinyl chloride (CPVC) and chlorinated polyethylene (CPE) coatings. [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]

Purpose: To develop a surface coating of sol-gel 70S30C bioactive glass (BAG) nanoparticles on titanium disks and dental implants and characterize the BAG coating from the standpoint of average surface roughness, adhesion strength, and coating stability upon implant insertion under clinical settings. Materials and Methods: BAG was prepared using a modified sol-gel technique, then milled into nanoparticles. The resultant powder was characterized in terms of phase structure, composition, and particle size. Titanium disks and dental implants were coated with BAG nanoparticles via electrophoretic deposition. Surface characterization of coated implants was conducted. Uncoated and BAGcoated implants were examined for average surface roughness using a confocal laser scanning microscope. Pull-off tests were conducted to measure the adhesion strength of the BAG coating to the underlying disks. To measure the amount of coating loss and evaluate the effect of insertion on coating thickness, coated implants were inserted under clinical settings into artificial and natural bones. Results: BAG nanoparticles had an amorphous structure with particle sizes < 20 nm in diameter. Electrophoresis resulted in a continuous coating that covered the whole implant surface. Microscopic analysis confirmed the porous nanostructure of the BAG coating, which formed a homogenous surface with microcracks. The BAG coating had a uniform thickness of 35.38 ± 4.67 μm. The average surface roughness was significantly lower for BAG-coated implants, with less surface irregularities (3.34 ± 0.45 μm for uncoated implants, 1.45 ± 0.23 μm for BAG-coated implants). An adhesion strength of 18.51 ± 3.37 MPa was recorded for the BAG coating. After insertion into artificial bone, 66.23 ± 10.23% of the coating weight remained on the implant surface. A reduction in the thickness of the BAG coating only occurred in sites of high friction with bone after implant insertion into bovine bone. Conclusions: Coating titanium implants with 70S30C BAG nanoparticles is attainable through electrophoretic deposition and results in a homogenous coating layer with a moderately rough surface, considerable adhesion strength, and high coating stability during implant insertion. [ABSTRACT FROM AUTHOR]

Magnesium alloys are nontoxic and promising as orthopedic metallic implants, but preparing a biocompatible Mg(OH)2 layer with high corrosion protection ability remains challenging. It is generally believed that the Mg(OH)2 layer, especially that formed in a natural condition, cannot provide desirable corrosion resistance in the community of corrosion and protection. Here, several Mg(OH)2 coatings were prepared by changing the pH values of sodium hydroxide solutions. These coatings were composed of innumerable nanoplatelets with different orientations and showed distinguished capability in corrosion resistance. The nanoplatelets were well-oriented with their ab-planes parallel to, instead of perpendicular to, the magnesium alloy surface by raising the pH value to 14.0. This specific orientation resulted in the optimal coating showing long-term corrosion protection in both in vitro and in vivo environments and good osteogenic capability. These finds manifest that the environment-friendly Mg(OH)2 coating can also provide comparable and better corrosion protection than many traditional chemical conversion films (such as phosphate, and fluoride).

Surface preparation is a fundamental thing that must be done before applying the coating to the material. A good painting will be obtained with good surface preparation treatment. This research aims to determine the effect of different surface preparation methods and various types of paint on adhesion strength and impact coating resistance. The type of material used in this research is SS400 steel with three different surface preparation methods, namely sandblasting, power tools, and hand tools following ISO 8501-1 standards, and with a variety of three different types of paint, namely epoxy, polyurethane, and alkyd paint. Adhesion strength testing uses the pull-off test method and impact resistance testing is carried out using the impact coating test. This test is carried out after the coating has been applied and the paint has dried completely. The results of the tests that have been carried out show that the highest average adhesion value of the three surface preparation methods carried out is obtained from polyurethane coatings. The best coating durability test results were obtained by polyurethane paint with only cracks occurring using the hand tool method at a height of 0.6 m. The conclusion obtained is that the best type of coating in this research is polyurethane coating and the best method is cleaning using the sandblasting method.

The electrodeposition of copper (Cu), silver (Ag), and their alloys has been a subject of interest since the 19th century. Primarily due to their exceptional features such as good mechanical hardness and electrical conductivity, high resistance to corrosion, and electromigration, Cu–Ag electrodeposits continue to be investigated and developed to improve their properties for different applications. This paper reviews the state of the art in the field of electroplated Cu–Ag alloys in an aqueous solution, with particular emphasis on the observed properties and variety of electrochemical processes used to produce high-quality materials. Moreover, this review paper focuses on the experimental conditions employed for Cu–Ag electrodeposition, intending to understand the basis and manipulate the processes to obtain coatings with superior characteristics and for attractive usage. Finally, the most trending applications of these coatings are discussed depending on different parameters of electrodeposition to provide prospects for potential research.

High heat generation is the main problem that sophisticated electronic devices can suffer. The pool boiling process can offer an excellent heat dispassion at constant temperatures. Therefore, it is one of the most powerful cooling processes used in nuclear power plants, data centers, air conditioning, etc. Because of that, enhancing pool boiling has become a goal of many recent investigations. The current paper presents an experimental study to evaluate the effect of nano and nanocomposite coating on the performance of pool boiling of deionized water under atmospheric pressure. Four surfaces made of copper were used in this study: smooth, CNT (1 g), GNPs (1 g), and (CNT-GNPs (1:1) g) surfaces. A four-step electro-deposition method was used to fabricate a nickel coating using the abovementioned materials. The variation in coating materials offers different surface wettability and roughness to the fabricated surfaces. The experiment's outcome revealed that the hydrophilic material can enhance the critical heat flux (CHF). The mixed wettability obtained by the nanocomposite coating can improve the heat transfer coefficient (HTC). Maximum enhancement in the CHF is obtained by GNPs (1 g) surface with 102%, while the maximum HTC is obtained by (CNT-GNPs (1:1) g) surface with 154% when it is compared with the plain surface.

Photointiators have been commercially applied in ultra-violet photocuring ink, varnish, coating, lacquers since 1970s. The significant advantages of efficient, energy-saving and environmental-friendly make them more and more popular in automobile industry, package industry, etc. Photointiators can reach foodstuff by vapour or diffusion from the food contact layer of the package. Although UV ink is just printed in the outer surface of the package, the residue photointiators can transfer to the inner surface by “set-off” effect. Different photointiator has different chemical and physical properties, and shows different response by different testing instrument. In this study, two methods of liquid chromatography time-of-flight mass spectrometry (LC-QTOF MS) and gas chromatography triple quadrupole mass spectrometry (GC-MS/MS) were developed for determination of migration for 23 photoinitiators in food contact coating. The response of the photointiators by two methods was compared for method selection. For the LC-QTOF MS method, an Hypersil GOLD AQ C18 column was utilized and 0.1% formic acid water-methanol was used as mobile phase. QTOF MS was performed by electrospray ion source positive ion mode (ESI+) and mutiple reaction monitor high resolution (MRM HR) mode. Simple dilution with acidified methanol was used for migration solution pretreatment and internal standard method was used for quantification. The limits of detection are from 0.0025 to 0.01 mg/kg. Recoveries range from 60.9% to 124%, and the relative standard deviations (RSDs) are between 0.9% and 11.6%. For GC-MS/MS method, a CD-5 column was used, and the MS/MS was operated under MRM mode. Liquid-liquid extraction with n-hexane was used for migration solution pretreatment and internal standard method was also used for quantification. The limits of detection range from 0.0004 to 0.002 mg/kg. The recoveries range from 77.0% to 128%, with RSDs are between 0.4% and 8.1%. Migration solution of 13 batches of metal coating samples were tested, while 5 of them are positive of photoinitiaor TPO or 2,4-diethyl-9H-thioxanthen-9-one, while the maximum detection value of photoinitiaor TPO is 0.0502 mg/kg, the detection values of 2,4-diethyl-9H-thioxanthen-9-one are all less than 0.002 mg/kg. The two methods are easy, sensitive and accuracy, which can determine the migration of photointiators in food contact coating.

Complex formation structures lead to significant differences in the failure mechanisms of hobs. WC-reinforced medium entropy composite coatings exhibit excellent comprehensive properties. However, the wear mechanism of coatings in different formation structures is still unclear. In this study, FeNiCr-WCx (x = 0, 40, 50, 60 wt%) composite coatings were prepared on the surface of H13 steel using laser cladding technology. The friction and wear mechanism of FeNiCr-WC composite coatings under different friction pair conditions was discussed. The results show that FeNiCr-WC composite coatings mainly consist of reinforced phase, lamellar eutectic structure and solid solution phase. As the WC content increases, the content of M6C and carbide phases in these coatings increases. The average microhardness of 40WC, 50WC and 60WC coatings is 3.28 times, 3.61 times and 4.20 times that of H13 steel, respectively. The wear rates of 40WC, 50WC and 60WC coatings are respectively about 0.25, 0.10 and 0.06 times that of FeNiCr coating under Al2O3 friction pair conditions. Three-body wear and oxidation wear mainly occurred on the surface of FeNiCr-WC composite coatings. The wear rates of 40WC, 50WC and 60WC coatings are respectively about 0.34, 0.35 and 0.16 times that of FeNiCr coating under Si3N4 friction pair conditions. Glaze layers with high Si content were formed on the surface of 50WC and 60WC coatings. The glaze layer is prone to cracking and peeling, resulting in increased wear rates for both coatings. As the hardness of the coating increases, the GCr15 friction pair undergoes severe abrasive wear.

To investigate the influences of Cr2AlC mass fraction and supersonic plasma spraying process on the microstructure and mechanical properties of Cr2AlC reinforced 410 stainless steel composite coatings, the coatings containing different mass fractions of Cr2AlC were prepared and investigated. The composite coating exhibited low porosity and high adhesion strength. The addition of Cr2AlC significantly enhanced the hardness of the composite coatings through particle strengthening. However, when the mass fraction of Cr2AlC was 20%, the aggregation of Cr2AlC resulted in a strong decrease in the coating preparation efficiency, as well as a decline in adhesion strength. In the supersonic plasma spraying process, the Ar flow rate mainly influenced the flight velocity of the particles, while the H2 flow rate and the current mainly affected the temperature of the plasma torch. Consequently, all of them influenced the melting degree of particles and the quality of the coating. The lowest porosity and the highest hardness and adhesion strength could be obtained when the Ar flow rate is 125 L/min, the H2 flow rate is 25 L/min, and the current is 385 A.

Introduction. Coatings on hard materials are widely used in many industries. Coating technologies help prevent or reduce corrosion, contamination and biofouling, chemical and structural degradation, and wear and tear of external surfaces due to exposure to the elements and natural environments. The range of materials used for functional coatings is quite wide: from organic polymers to hybrid composites and inorganic nanoparticles, depending on the desired properties and functionality of the final product. Despite the excellent anti-corrosion characteristics of non-polymer coatings, their usage causes environmental damage. Organic coatings are among the most widely used. Such compositions are applied in liquid form; organic solvents are one of the main components. Environmental concerns have encouraged the development of alternative technologies. The main areas for development are availability of raw materials and the cost of environmentally friendly coatings. Results and discussion. The review substantiates the relevance of research on the development of multifunctional polymer-based coatings. The market for polymer coatings is presented. Methods of surface protection, types of coatings formed, their main components, features of the formation of coatings, the influence of various factors on the formation of polymer coatings, including methods of preparation and pre-treatment of the protected surface are presented. Methods for preventing corrosion are discussed in detail, as well as the main directions in the development of anti-corrosion coatings based on various protective mechanisms. The characteristics of the main components of protective coatings are given. The issue of destruction of polymer coatings depending on the operating environment is considered in detail. The types of media, their influence and mechanisms of action on protected objects are considered. Factors and mechanisms of destruction of polymer coatings, methods for preventing degradation of coatings are listed. The latest technologies for the formation of protective polymer coatings are highlighted. Conclusion. Currently, coatings provide a wide range of quality indicators. An important characteristic of modern coatings is minimal negative impact on the environment, which requires an integrated approach to the design and production of coatings.

In this research, a nickel-tungsten coating as a catalyst for hydrogen evolution reaction (HER) with different current densities was synthesized and the resulting electrocatalytic properties and morphology were assessed. Linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and chronoamperometry in 1 M NaOH were used to evaluate the electrocatalytic activity for HER. By increasing the current density of electrodeposition up to 500 mA/cm2, a columnar morphology was observed. The cyclic voltammetry test (CV) revealed that when the plating current density increases, Cdl has increased from 248 to 1310 µF/cm2 and the active surface area increases 5 times. The results showed that by modifying the coating morphology, the current density of the hydrogen evolution increased up to two times.

Construction and demolition waste (CDW) management should focus on reducing CDW or properly recycling the materials since this waste is now a global problem. Sand brick waste, a component of a building’s structure, is one type of CDW. To be used as recycled aggregate, these wastes are invariably categorised as low grade. Due of the improved qualities provided, geopolymer research has recently become more popular. The objective of this study is to investigate the physical and mechanical properties of recycled sand brick aggregate (RSB) treated with silica fume based geopolymer coating. Additionally, the effectiveness of the treated RSB will be applied in concrete as coarse aggregate. The sample was made using a solid-to-liquid ratio of 1.0, 1.2, 1.4, 1.6, and 1.8. At 2.5 and 10 M, alkaline activator is a constant variable. Testing of specific gravity, water absorption, and aggregate impact value were analysed. The treated RSB concrete will then be evaluated against normal concrete. In terms of density, water absorption, and compressive strength, natural concrete performs better than treated RSB concrete. In comparison to natural concrete, treated RSB concrete absorbs 5.8% more water. Treated RSB concrete has a density of 1815 kg/m3, compared to natural concrete’s 2080 kg/m3. The compressive strength of concrete made using treated RSB aggregate is 18.1 MPa after 7 days, and 27.1 MPa at 28 days. The testing revealed that the treated RSB aggregate concrete met the specifications. As a result, treated RSB aggregate concrete offers an advantage over natural OPC concrete while saving the environment.

Abstract Researchers face significant challenges because of the inadequate corrosion resistance and weak adherence of epoxy (EP) coatings. We deal with these issues here by means of a novel nano-composite coating (EP/nano-CoS2). In order to create a composite coating (EP/nano-CoS2), CoS2 nanoparticles (nano-CoS2) were prepared and incorporated to an epoxy (EP) resin. The synthesized CoS2 was characterized using XRD and FT-IR spectroscopic techniques. The mean particle size was determined using Scherer equation and found to be 19.38 nm. The zeta potential was also determined (− 9.78 mV). Electrochemical impedance spectroscopies (EIS) as well as pull-off assessments were used to quantify the EP/nano-CoS2 coating’s anti-corrosion capabilities and adhesive power. The findings demonstrate that the EIS variables of the EP/nano-CoS2 composite coating are markedly improved when compared to raw EP coating. The corrosion resistance or even adhesion of EP protective layer can be markedly increased by using the synthesized nanoparticles as nano-fillers.

In order to investigate the effect of filling different masses of inorganic filler CeO2-ZrO2-Al2O3(CZA) powder on the anticorrosive and mechanical properties of acrylic coatings, CZA powder samples were synthesized by drying and calcination using the co-precipitation method. The obtained CZA powder was fully dispersed in acrylic resin with commonly used dispersants, defoamers and other additives available in the market, and the acrylic anticorrosive coatings with different mass fractions were prepared on treated iron plates by the scraping method. Meanwhile, the XRD, SEM and EDS methods were used to analyze the physical phase of the CZA powder samples, and the mechanical property tests and electrochemical anticorrosion property tests were utilized to evaluate the characteristics of the coatings, such as adhesion, hardness, roughness, bending performance, wear resistance, tensile strength, elongation at break and anticorrosion performance. Results showed that the as-prepared CZA powders were solid solutions and showed a tetrahedral structure. After adding CZA powder, the hardness of the coating increased from HB to 1H, the bending properties were all 1T, wear resistance was improved, and adhesion was all grade 1. CZA increased the anticorrosive properties of the coatings compared to acrylic anticorrosive coatings without CZA addition, and the best anticorrosive properties of the coatings were obtained when the mass fraction of filler addition was 10%. Overall, the acrylic anticorrosive coating had certain anticorrosive properties and could effectively prevent the corrosion of corrosive media on the material, which presented certain application prospects in the field of anti-corrosion in the future.

Coating modification is an important way to enhance the reactivity of aluminum powder. In this paper, ammonium perchlorate and aluminum powder were assembled into energetic microunits by liquid deposition method. Spherical particles with AP as shell and ultrafine aluminum powder as the core (Al@AP) were gained. The micromorphology results show that the coated particles are about 5 μm, and the coating layer is evenly distributed on the outer surface of aluminum powder, indicating a complete coating. The energetic microunits were implanted into the nitrate ester plasticizing adhesive system (NEPE) as solid phase fillers. The effect of filler on the rheological properties, safety, mechanical properties, thermal reaction and energy properties of the system was analyzed by comparing with the raw aluminum filler. The test results show that the rheological properties, mechanical properties and pressure index of NEPE containing system Al@AP meets the requirements of solid propellant charging. Compared with Al based propellant, the mechanical sensitivity and thermal sensitivity are decreased, the safety is better, and the explosion heat of the propellant is increased by 7.8%. The engine test shows that the specific impulse is increased by 1.2 s. Al@AP can improve the energy output and safety of NEPE propellant, and has potential application prospects in high-energy propellants.

The fabrication of transparent conducting electrodes (TCEs) is dominated by indium tin oxide (ITO). Some efforts are being made to find alternative materials as a substitute for ITO. Cu nanowire (CuNWs) is an equivalent candidate as a replacement for ITO but has a weakness that is easily oxidized. In this contribution, we report an increase in the performance of CuNWs, which can reduce the effect of oxidation. In this study, we provide a coating of CuNWs using PVP, PVA, and silver nanoparticles (AgNPs). The morphology, formation structure, and conductivity of CuNWs have been investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), and IV meter. The average length and diameter of the CuNWs were 5.5 μm and 120 nm, respectively. The transparent conducting has a stable conductivity after coating with PVP, PVA and AgNPs. The application of transparent conducting electrodes are sensors, electronic devices, solar cells, and organic light-emitting diodes (OLEDs).

Metallic zinc has emerged as a promising anode material for high‐energy battery systems due to its high theoretical capacity (820 mAh g−1), low redox potential for two‐electron reactions, cost‐effectiveness and inherent safety. However, current zinc metal batteries face challenges in low coulombic efficiency and limited longevity due to uncontrollable dendrite growth, the corrosive hydrogen evolution reaction (HER) and decomposition of the aqueous ZnSO4 electrolyte. Here, we report an interfacial‐engineering approach to mitigate dendrite growth and reduce corrosive reactions through the design of ultrathin selective membranes coated on the zinc anodes. The submicron‐thick membranes derived from polymers of intrinsic microporosity (PIMs), featuring pores with tunable interconnectivity, facilitate regulated transport of Zn2+‐ions, thereby promoting a uniform plating/stripping process. Benefiting from the protection by PIM membranes, zinc symmetric cells deliver a stable cycling performance over 1500 h at 1 mA/cm2 with a capacity of 0.5 mAh while full cells with NaMnO2 cathode operate stably at 1 A g−1 over 300 cycles without capacity decay. Our work represents a new strategy of preparing multi‐functional membranes that can advance the development of safe and stable zinc metal batteries. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) have garnered extensive attention owing to their excellent biocompatibility, elevated specific surface area, and facile functionalization, as well as their diverse methods of preparation. In recent times, CDs have been applied for anti‐corrosion and obtained some significant results. In this work, the preparation methods of CDs are first briefly introduced, and the relative merits of different approaches are highlighted. Subsequently, the application of CDs in the realm of corrosion inhibitors is discussed, and the corrosion inhibition effects and mechanism of nitrogen‐doped CDs, nitrogen and sulfur‐co‐doped CDs, as well as CDs functionalized with other elements and nitrogen‐co‐doped are summarized. Finally, the application of CDs and functionalized CD‐modified coatings for anti‐corrosion and their protective mechanism is analyzed in detail. This review summarizes recent progress in research related to CDs and heteroatom‐doped CDs in anti‐corrosion applications and anticipates the prospects and applications of CDs in corrosion protection. With their unique properties and versatile applications, CDs are expected to assume a progressively pivotal role in the advancement of cutting‐edge corrosion protection technologies. [ABSTRACT FROM AUTHOR]

The tribological performance of the tungsten carbide substrate (WC‐Co), improved by ceramic coatings, is still being reported in new studies that have been carried out to date. It has become a hot research topic that are widely applied in hard material research, especially in the tools manufacturing fields. This study was conducted to investigate the wear characteristics of a commercial cemented carbide tool (WC‐Co) coated with a physical vapor deposition chromium‐vanadium nitride film (CrVN), followed by a boriding process as a final thermochemical treatment. Tested in dry sliding contact against an alumina ball as a static partner, the tribological responses of the specimen were analyzed and compared with an uncoated specimen. Friction coefficients, calculated from volume loss, were around .58 for all specimens except the uncoated specimen at 10 N of applied load. Wear scar analyses revealed the occurrence of several wear mechanisms that is polishing, oxidation, wear debris formation, surface binder removal, grain fragmenting, and grain pull‐out. [ABSTRACT FROM AUTHOR]

The article presents the results of research on the impact of the use of an original, innovative method of deposition of Parylene C on the functional properties of fabrics with various potential applications (e.g., thermal and chemical protective clothing, packaging, covers and others). Verification of the effects of the method used was based on interdisciplinary research taking into account the impact of coating fabrics on changes in their structure (micro-CT), surface properties (contact angle), barrier properties (water and chemical liquid wetting), electrostatic properties (charge decay), biophysical properties describing heat and mass transfer (by the Alambeta system and thermal imaging) and flammable properties. Four fabrics made of synthetic organic fibres (meta-aramid, para-aramid) and natural inorganic fibres (basalt) were selected for testing. Given the complex structure of textile substrates, the results confirmed that the two assumed thicknesses of the Parylene C coating were consistent with the actual measurements. The findings indicated that the coatings significantly reduced water and acid absorption in the fabrics compared to unmodified ones. Thermal insulation property tests revealed that coated fabrics exhibited higher thermal conductivity than unmodified fabrics. Additionally, the presence of Parylene C on aramid fabrics resulted in a modest increase in their ignition resistance. [ABSTRACT FROM AUTHOR]

Polyurethane (PU) coatings are used in diverse applications such as textile coating. Up to today, landfilling is still the most occurring way of processing PU waste. Biodegradation is an alternative route for processing PU waste and decreases the amount of microplastics in the case of landfilling. In this study, a biodegradable PU textile coating was developed. The PU was characterized via Fourier-transformed infrared (FT-IR) thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The PU was thermoplastic and had a melting point of approximately 33 °C. The performance of the coating was studied by assessing the water barrier and mechanical properties. The PU coating completely disintegrated, and the biodegradation of PU was assessed in soil and was almost 60%. Furthermore, the plant toxicity was examined by evaluating seedling emergence and growth. [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]

Sol-Gel is formed by conversion of liquid precursor into a sol and then to a gel. This technique is a common process for forming porous materials via solidification from a real solution phase. Preparation of homogenous solution, hydrolysis, gelation, drying, densification are major steps in sol-gel formation. Sol-Gel derived materials include glasses, ceramics, and nanoparticles, each offering unique properties and characteristics tailored to particular applications. Sol-Gel offers a distinct pathway for creation of many new and conventional nanomaterials that had been improved by combustion or hydrothermal treatment. This review highlights sol-gel process, steps involved in preparation and applications in medicine. [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]

In this study, corrosion control of mild steel in acidic media was conducted in the presence of polyvinyl alcohol (PVA)‐chitosan and PVA‐chitosan‐dopamine composite coatings. Weight loss, polarization, and electrochemical impedance spectroscopy (EIS) studies were conducted to study the protective mechanisms and performance of PVA‐chitosan coatings. The results showed a substantial reduction in weight loss, corrosion rates, and corrosion current densities for coated specimens indicating the effectiveness of the composite coatings. PVA‐chitosan and PVA‐chitosan‐dopamine coatings showed high inhibition efficiencies (IE) up to 90.65 % and 96.01 % respectively. The electrochemical findings were supported using surface characterization techniques such as SEM to obtain a complete understanding of the coatings' morphology and composition. The topographical analysis confirmed that dopamine significantly influenced the surface morphology and behavior of the nanocomposite. The FTIR spectrum of composite B, which combined PVA and chitosan, exhibited notable changes, including a decrease in both the intensity and frequency of the OH band. The potential of PVA‐chitosan‐dopamine coatings as effective corrosion inhibitors for mild steel in acidic environments offered practical solutions for diverse industrial applications. [ABSTRACT FROM AUTHOR]

Sustainable and environment‐friendly polymer composite smart paints/coatings with polyurethane (PU) derived from castor‐oil (CO) as the matrix and barium titanate (BTO) microparticles as piezo‐active inclusions (2, 4, 6, 8, and 10 vol.%) have been prepared employing ultrasonication and solvent casting, followed by contact DC poling method. Relative dielectric constants varied from 5.26 ± 0.37 for pristine COPU to 8.9 ± 0.36 for COPU/10 vol.% BTO composite, at a frequency of 1 kHz. Piezoelectric strain constant d33 of the poled films varied from 0.0 pC/N for pristine castor‐oil based polyurethane (COPU) to 1.2 pC/N for COPU/10 vol.% BTO (CPBT‐5) composite. Tensile tests showed that the elastic modulus varied from 1.98 ± 0.003 MPa for pristine COPU to 5.13 ± 0.02 MPa for COPU/10 vol.% BTO composite. Dynamic mechanical analysis confirmed the viscoelastic nature of the smart paints. Measurement of current–voltage response under different compressive loads indicates that COPU/10 vol.% BTO composite can generate a current of ~28 nA and voltage of ~8 V under a dynamic compressive load of 40 N, applied at a frequency of 1 Hz. These experiments were complemented by Fourier transform infra‐red spectroscopy and scanning electron microscopy. In addition, finite element analyses based on periodic boundary conditions have been performed to predict the effective electro‐elastic properties of these piezoelectric smart composite coatings. Highlights: Castor‐oil‐based PU piezoelectric composites with BTO inclusions were developed.Increase in BTO content up to 10 vol.% increases dielectric constant by ~1.7 times.COPU/BTO composites exhibit significantly increased piezoelectric response.Elastic and viscoelastic properties are also enhanced with increasing BTO content.Finite element models show a good match with experimental results. [ABSTRACT FROM AUTHOR]

Highlights Polyimide composites are easily degraded in high temperature and high humidity environments for long service, which reduces their reliability and stability in aerospace, electronic components, weapons, and other fields. In this paper, the inorganic and organic multiphase double‐layer coating was prepared. The insulating layer was made of vinyl polysilazane resin as the base material and hollow glass microspheres as the filler. The hydrophobic layer consisted of polydimethylsiloxane as the base material, hollow phenolic microspheres, and nano‐TiO2 as the filler. The heat resistance, hydrophobic properties, and aging resistance of the coated polyimide resin matrix composites were studied. The results showed that the thickness of the double‐layer coating was about 200 μm. Under the 200°C thermal insulation test, the maximum temperature drop can be achieved at 59.7°C. After adding 5 wt% TiO2, the static contact angle of composites was increased from 86.2° to 127.7°. Significantly, the hydrophobic performance was improved by 48.1%, which was due to the construction of micro‐nano structures in the surface layer coating. In the accelerated hydrothermal aging tests, the bending properties of coated composite materials can be improved by 8.5%, 3.2%, and 8.7% in water, alkali, and acid environments, respectively. The moisture absorption of glass fiber and the pyrolysis of polyimide led to the degradation of the mechanical properties. The existence of heat‐resistant and hydrophobic coating could effectively eliminate this adverse effect, which was of great significance for polyimide composites to cope with various service environments. A novel coating consisting of thermal insulating and hydrophobic layers was developed on glass fiber reinforced polyimide composites (G/PI) composites. The maximum temperature drop of coating can be achieved at 59.7°C. The static contact angle of coated G/PI composites was increased from 86.2° to 127.7°. In the aging tests, the protective effect of the coating resulted in improved mechanical strengths of G/PI composites. The microscopic damage morphology was performed to analyze the anti‐aging properties of the coating. [ABSTRACT FROM AUTHOR]

Aqueous zinc‐ion batteries (AZIBs) are considered promising candidates for large‐scale energy storage due to their high safety, low cost, and environmental friendliness. As a core component, separator plays a unique yet oftentimes overlooked role in providing electrochemical stability in AZIBs. This concept focuses on the exquisite structure‐property relationship of separators, highlighting three forms of these components and their structural design requirements, i. e., traditional membranes, solid‐state electrolytes, and electrode coatings. The mechanism by which separators influence the zinc anode and the cathode is discussed. The article also identifies the challenges and potential future directions for functional separators in the development of high‐performance AZIBs. [ABSTRACT FROM AUTHOR]

Feed spacers improve mixing and mass transfer in membrane modules. However, they also lead to foulant deposition in the vicinity of the spacer surface. In this paper, two hydrophilic monomers, namely, acrylic acid (AA) and 2‐hydroxyethyl methacrylate (HEMA), are respectively coated on the surface of a commercial feed spacer via a plasma‐enhanced chemical vapor deposition (PECVD) method. The resulting modified spacers are then evaluated alongside with a reverse osmosis (RO) membrane for its solute rejection, water permeability, and antifouling properties. Results show that the surface hydrophilicity of feed spacers has been enhanced upon the AA and HEMA deposition. During filtration test, the HEMA‐modified spacer demonstrates higher flux recovery rate (94.17%) and salt rejection (95.78%) for the RO membrane. In contrast, the membrane with the unmodified spacer only shows 89.44% and 92.46%, respectively. Additionally, the membrane with the HEMA‐modified spacer has a thinner fouling layer (200 nm) compared to the unmodified spacer (700 nm). The HEMA‐coated spacer outperforms all the tested spacers, demonstrating that feed spacer modification with a hydrophilic monomer via the PECVD method can effectively reduce membrane fouling. [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]

OBJECTIVES Our objective was to explore the safety and efficacy of a graphene oxide-loaded rapamycin-coated self-expandable metallic airway stent (GO@RAPA-SEMS) in a rabbit model. METHODS The dip coating method was used to develop a GO@RAPA-SEMS and a poly(lactic-co-glycolic)-acid loaded rapamycin-coated self-expandable metallic airway stent (PLGA@RAPA-SEMS). The surface structure was evaluated using a scanning electronic microscope. The in vitro drug-release profiles of the 2 stents were explored and compared. In the animal study, a total of 45 rabbits were randomly divided into 3 groups and underwent 3 kinds of stent placements. Computed tomography was performed to evaluate the degree of stenosis at 1, 2 and 3 months after the stent operation. Five rabbits in each group were sacrificed after the computed tomography scan. The stented trachea and blood were collected for further pathological analysis and laboratory testing. RESULTS The in vitro drug-release study revealed that GO@RAPA-SEMS exhibited a sudden release on the first day and maintained a certain release rate on the 14th day. The PLGA@RAPA-SEMS exhibited a longer sustained release time. All 45 rabbits underwent successful stent placement. Pathological results indicated that the granulation tissue thickness in the GO@RAPA-SEMS group was less than that in the PLGA@RAPA-SEMS group. The TUNEL and hypoxia-inducible factor-1α staining results support the fact that the granulation inhibition effect in the GO@RAPA-SEMS group was greater than that in the PLGA@RAPA-SEMS group. CONCLUSIONS GO@RAPA-SEMS effectively inhibited stent-related granulation tissue hyperplasia. [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]

This study investigates the performance enhancement of mandrel-coiled twisted and coiled polymer fibers with a nichrome heater (TCPFLNR) by coating with a solution of graphene–mesoporous carbon–nickel–polyvinyl alcohol. The coating process involved a one-pot synthesis utilizing graphene powder, Ni nanoparticles, mesoporous carbon, and PVA as a binding agent. The coating was performed by manually shaking the TCPFLNR and the subsequent annealing process, which results in improved thermal conductivity and actuation behavior of the TCPFLNR. Experimental results on a 60 mm long actuator demonstrated significant enhancements in actuation displacement and actuation strain (20% to 42%) under various loads with an input current of 0.27 A/power 2.16 W. The blocked stress is ~10 MPa under this 2.16 W power input and the maximum strain is 48% at optimum load of 1.4 MPa. The observed actuation strain correlated directly with the input power. The coated TCPFLNR exhibited better thermal contacts, facilitating enhanced heat transfer, and reducing power consumption by 6% to 9% compared to non-coated actuators. It was found that the nanomaterial coating helps the TCP actuator to be reliable for more than 75,000 actuation cycles at 0.1 Hz in air due to improved thermal conductivity. These findings highlight the potential for further research to optimize electrothermally operated TCP actuators and unlock advancements in this field. [ABSTRACT FROM AUTHOR]

In this study, a comparative analysis of silver nanoparticles treatment and chitosan coating on packaging paper barrier properties was carried out. In order to examine the water, grease, and antibacterial barrier properties of silver nanoparticle-treated and chitosan-coated laboratory-obtained paper samples, a mixture of bleached softwood and hardwood celluloses was used. In order to conduct the comparative analysis SEM, water contact angle, Cobb60, and Kit tests were carried out on a cellulose sample, and four paper samples (three of them treated with silver nanoparticles—1, 2, and 3 mL/20 cm2 or chitosan coated—0.5, 1, and 2 g/m2) together with the inhibition activity against nine Gram-positive and Gram-negative bacteria, yeast, and fungal strains. The study found out that increasing the silver nanoparticle treatment and chitosan coating led to improved water resistance, while grease resistance was improved only for chitosan coated paper samples. Additionally, paper treated with 3 mL/20 cm2 of silver nanoparticles had the highest antibacterial protection (81.6%) against the Gram-positive bacterium Staphylococcus aureus, followed by Gram-negative Escherichia coli (75.8%). For the rest of the studied microorganisms, the average efficiency of the treated paper was 40.79%. The treatment of the paper with 1 and 2 mL/20 cm2 of silver nanoparticles was less effective—27.13 and 39.83%, respectively. The antibacterial protection of 2 g/m2 chitosan-coated paper samples was the most effective (average 79%) against the tested bacterial, yeast, and fungal strains. At 1 and 0.5 g/m2 chitosan coatings, the efficiency was 72.38% and 54.67%, respectively. Gram-positive bacteria, yeasts, and fungal strains were more sensitive to chitosan supplementation. [ABSTRACT FROM AUTHOR]