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Cylinder bore coatings are widely used in automotive internal combustion engines to replace cylinder liners. During the atmospheric plasma spraying process, the coatings are oxidized and controlled by the Si content of the steel powder used as the coating raw material. This phenomenon affects the technological process, the microstructure, and the properties of the formed coatings. The research aims to investigate how the Si content of two commercial grades of steel powder commonly used in industry affects the undesirable consequences observed in practice, such as clogging of powder nozzles or large variations in coating hardness. The analyses and industrial experiments show that increasing the Si content can contribute significantly to these undesirable phenomena. [ABSTRACT FROM AUTHOR]

Rare earth ytterbium monosilicate (Yb 2 SiO 5) is one of the most ideal candidates for environmental barrier coatings. In this paper, Yb 2 SiO 5 coating was successfully fabricated by atmospheric plasma spraying technology. The effect of main gas flow rate and spraying powder composition on the microstructure and phase composition of Yb 2 SiO 5 coating were systematically investigated to solve the volatilization of SiO 2 during plasma-spraying process. The results showed that Yb 2 SiO 5 coating was relatively dense with the less internal defects under the main gas flow rate of 35 L/min, and the main gas flow rate from 30 L/min to 40 L/min had no significant effect on the melting effect of spraying powder and the porosity of coating. Yb 2 SiO 5 coating was composed of Yb 2 O 3 , Yb 2 SiO 5 two crystal phases and amorphous phase. The phase composition of coating was not affected by the change of main gas flow rate. After heat-treatment at 1400 °C for 20 h, Yb 2 SiO 5 crystal phase precipitated from the coating, and the content of Yb 2 SiO 5 phase reached 74.29 mol%, and the remaining phase was Yb 2 O 3 phase. The Yb 2 SiO 5 -25.71 mol% SiO 2 coating was still dense, the content of Yb 2 SiO 5 crystal phase was up to 97.76 mol% after heat-treatment, and the content of Yb 2 Si 2 O 7 phase was only 2.24 mol%, indicating that excessive addition of a certain amount of SiO 2 could compensate for the volatilization of SiO 2 , so as to prepare Yb 2 SiO 5 coating with approximate stoichiometric ratio. [ABSTRACT FROM AUTHOR]

Lisa Dart's memoir, "Fathom: An Uncovering of Trauma," explores the author's experiences with trauma and mental illness. Dart's narrative is driven by her desire to reclaim the past and understand the event that occurred when she was four years old, when her father attempted suicide. Through vivid imagery and references to art and literature, Dart delves into her own psyche and uses creativity as a means of uncovering and processing her trauma. The memoir is structured around the recurring thought of her father's suicide attempt and the presence of blood, and it explores the complex relationship between madness, remembrance, and creativity. [Extracted from the article]

Developing effective latent curing agent for rapid curing of epoxy resins at low temperatures remains challenging. This study reports a latent curing agent, ortho‐cresol phenolic epoxy resin‐bisphenol A (EOCN‐BPA), prepared through the addition reaction of o‐methyl phenolic epoxy resin with BPA. When blended with dicyandiamide (DICY) in a 1:3 molar ratio, EOCN‐BPA/DICY is used to cure a linear epoxy phenolic novolac (EPN) resin (epoxy equivalent: 550 g eq−1, softening point: approximately 82°C), at an onset curing temperature of 90°C, which is considerably lower than the onset curing temperature of DICY with EPN (160°C). However, EOCN‐BPA does not react with EPN without a catalyst. Therefore, this latent curing system is successfully applied in powder coatings, rapid curing at 120°C within 3 min without an additional catalyst, outperforming the EPN/EOCN‐BPA system using cocatalyst 2‐methylimidazole. Consequently, DICY catalyzes the curing reaction between the phenol hydroxyl group and epoxy resin and participates in it. The prepared powder coating exhibits excellent storage stability, maintaining its properties for over 3 months at room temperature. These findings demonstrate the excellent latent properties of EOCN‐BPA/DICY, highlighting its potential as a highly effective latent curing agent. [ABSTRACT FROM AUTHOR]

Innovative powder coating system for hydraulic steel construction Unprotected steel corrodes in the atmosphere, water and soil. In order to ensure structural safety and maintain fatigue strength, steel structures of all kinds must be protected from corrosion. Hydraulic steel structures such as locks, gates, canal bridges, ship lifts and water power plants largely characterize our waterways, coastal fortifications and port facilities. They are exposed to a particularly high level of corrosive attack because, in addition to atmospheric influences such as wind and weather, they are particularly affected by water, constant water changes and aggressive substances such as salts and minerals. Since such constructions and buildings usually represent investments of the century, their preservation, use and operational safety over generations is an economic necessity. But it′s not just corrosion that poses a problem for hydraulic steel construction; the formation of biofilms and the growth of algae and mussels can also lead to problems that can even lead to a restriction in the functionality of the systems. The newly developed powder coating system prevents both and thus helps to extend maintenance intervals, increase the lifecycle of steel components in hydraulic steel construction and reduces the lifecycle costs. The new powder coating system thus makes an innovative and sustainable contribution to the preservation of structures in hydraulic steel construction. [ABSTRACT FROM AUTHOR]

The influence of different aluminum powder and dosage on the surface leveling, gloss and metal effect of the metallic powder coating has been investigated. Meanwhile, the effects of different polyester resin, additives (e.g., leveling agent, brightener, aluminum powder arrangement dispersant, etc.), extrusion processes, bonding processes, etc., on the metal effect of coating surface and the improvement of surface defects are discussed. It provides the theoretical basis for the production of metallic powder coatings and the solutions for the treatment of surface defects so as to ensure the quality of products. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Carbonyl soft magnetic composites (SMCs) have garnered significant attention due to their excellent high-frequency adaptability and outstanding properties, aligning perfectly with the development trend of electronic components. In this work, carbonyl FeNi50 powders were chosen as the research subject, and phosphating treatment was utilized to generate a phosphate coating layer on the surface of the powders. The influences of phosphoric acid concentrations on the compositions and structures of the phosphate coating layer on the powders' surface were systematically investigated by combining various characterization techniques. The presence of phosphates was successfully characterized, and the reactions between phosphoric acid and the FeNi50 powder were inferred. Subsequently, the magnetic properties of the SMCs were measured, and the influences of phosphoric acid concentrations on the magnetic properties of the SMCs were investigated. The comprehensive magnetic properties of SMCs were found to be optimal at a phosphoric acid concentration of 0.15 wt%. In particular, the DC bias performance of up to 91.0% and the permeability stability of up to 20 MHz could meet the requirements of high-frequency and large DC bias applications, indicating extensive application prospects. [ABSTRACT FROM AUTHOR]

Colourless glass particles are found in oil painting layers from the fifteenth-seventeenth centuries. Several historical sources mention the use of finely ground glass powder as a solid drier. In order to assess the siccative effect of glass particles added to paint, this research focused on red lake reconstructions and followed their natural drying using Fourier transform infrared (FTIR) analysis. Three glasses with different sodium-potassium and manganese contents were studied. Significant differences in drying rates were observed in each of the samples, indicating a relationship between both the composition – either enriched with or without manganese – and the size of the glass particles added as siccatives. This FTIR approach highlights several complex mechanisms involved in the drying effect of glass powders mixed in paint layers. [ABSTRACT FROM AUTHOR]

Copyright of Diamond & Abrasives Engineering is the property of Zhengzhou Research Institute for Abrasives & Grinding and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, the effects of different carboxyl polyester resins, GMA acrylic resins, curing agents, hydroxyl polyester resins and curing accelerators on the surface effect, mechanical properties and cold oven gloss stability of polyester acrylic soft skin-like powder coatings were discussed. By optimizing and adjusting the formula, the skin effect of the coating surface and the stability of the cold oven gloss were improved, and the physical properties of the coating such as impact and bending resistance were improved, so as to provide theoretical and experimental basis for the production of polyester acrylic skin-like powder coating with good physical properties such as stable gloss, strong skin-touched feeling, impact and bending resistance. [ABSTRACT FROM AUTHOR]

This work focused on obtaining a low-temperature powder coating characterized by self-healing properties. To achieve this, acrylic resin, blocked polyisocyanates (bPICs) with 1,2,4-triazole, and unsaturated commercial resin were used. The synthesis of bPICs with triazole enabled the low-temperature curing and reversible Diels–Alder (DA) reaction at 160 °C. The chemical structure of bPICs was confirmed using 1H-NMR. The occurrence of the DA and retro-DA (rDA) reactions in the crosslinked polymer, at temperatures of 60–85 °C and 90–130 °C, respectively, was confirmed using Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), and FT-IR spectroscopy. The self-healing properties of the powder coating were examined using polarized optical microscopy. Additionally, the occurrence of the DA and rDA reactions between triazole and unsaturated polyester resin was investigated through repeated self-healing tests. [ABSTRACT FROM AUTHOR]

Copyright of BHM Berg- und Hüttenmännische Monatshefte is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coatings & Protection / Tuceng yu Fanghu is the property of Coating & Protection Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coatings & Protection / Tuceng yu Fanghu is the property of Coating & Protection Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Protection against fire and the corrosion of metals is necessary to ensure human safety. Most of the fire and corrosion inhibitors do not meet the ecological requirements. Therefore, effective and ecological methods of protecting metals are currently a challenge for researchers. In this work, the influence of hexakis(4-(hydroxymethyl)phenoxy)cyclotriphosphazene (HHPCP) on the characteristics of powder coatings was examined. The coatings' properties were investigated by measuring the roughness, hardness, adhesion to the steel surface, cupping, gloss, scratch resistance, and water contact angle. The thermal stability was studied by furnace test and TGA analysis. The corrosion resistance test was carried out in a 3.5% NaCl solution. The distribution of phosphazene-derived segments in the coating was examined by GD-EOS analysis. Modified coatings show better corrosion and thermal resistance and can be used for the protection of the steel surface. Their better corrosion resistance is due to the electroactive properties of the phosphazene ring and its higher concentration at the coating surface, confirmed by GD-EOS analysis. The increase in thermal resistance is due to the effect of the formation of phosphoric metaphosphoric and polyphosphoric acids during the decomposition of HHCPC, which remain in the condensed char phase and play a crucial role in surface protection. [ABSTRACT FROM AUTHOR]

Raman spectroscopy (RS), for its robust analytical capabilities under constant development, is a powerful method for the identification of various materials, in particular pigments in cultural heritage. Characterization of the artist's palette is of fundamental importance for the correct formulation of restoration intervention as well as for preventive conservation of artworks. Here we examine the number and variability of research studies exploiting Bravo handheld Raman spectrophotometer relying on the excitation of Raman signal with temperature-shifted diode lasers emitting at 852 and 785 nm. To this end, we explore the spectral features of common historical pigments examined as powders and in the paint layer. We show that some materials may exhibit slightly different spectra as concerns especially the relative intensity of Raman lines with 852 nm laser excitation wavelength as compared to the standard 785 nm. The aim is to provide the research community with a reference spectral database that facilitates the identification of unknown pigments using the 852 nm excitation source. [ABSTRACT FROM AUTHOR]

In the present study, electrostatic powder coating waste was recycled and employed to reinforce high‐density polyethylene. The hydrolysis method was preferred to modify the powder coating waste of various systems, and they were mixed with high‐density polyethylene at various weight ratios. The mixtures were prepared in a mechanical mixer and then in an extruder to obtain a homogeneous mixture. This homogeneous structure was pressed into molds with a plastic injection device to obtain standard tensile samples. Mechanical and thermal tests were conducted on the samples. It was determined that the tensile stress of the sample decreased with the increase in filler content. The changes in sample tensile strength were investigated after the samples were aged. Three‐point bending strength of the samples was also investigated and it was observed that they became more resistant to vertical loads as the filler content increased. The Izod impact strength of the samples differed based on the filler type and weight ratio. Furthermore, mass loss in the produced mixtures was determined with thermogravimetric analysis. The matrix and filler bonding mechanisms were observed under an electron microscope. [ABSTRACT FROM AUTHOR]

The creep behavior of the oxide-dispersion-strengthened alloy GRX-810 fabricated by powder coating followed by laser-powder-bed fusion was evaluated via constant-stress, constant-heating-rate (CSCHR) tension testing using stresses of 69, 97, 121, and 173 MPa and a heating rate of 75 °C/min. Arrhenius plots derived from CSCHR strain-versus-temperature measurements revealed an apparent activation energy which increased with increasing stress. These findings were interpreted in terms of the effect of temperature on the threshold stress for creep deformation. [ABSTRACT FROM AUTHOR]

In this paper, the effects of different polyester resins, epoxy resins, fillers, different additives and extrusion processes on the surface scratch resistance of polyester epoxy matt powder coating and the improvement of surface bright marks are described. By adjusting the formula and process, the anti-scratch performance of the coating is improved. meanwhile, the bright mark defect on surface of coating is modified, which is useful to ensure product quality. [ABSTRACT FROM AUTHOR]

Magnesium alloys, because of their excellent strength-to-weight ratio, are increasingly used in many industries. When used in external elements, the key factor is to provide adequate anticorrosion protection. High-temperature, cured-powder coatings are widely used to protect most metals, but their use on magnesium alloys is difficult as a result of the instability of the magnesium substrate at elevated temperatures. Another problem is ensuring the proper adhesion of the organic coating to the magnesium substrate. This paper presents the procedure for the synthesis of a duplex coating on AZ91 magnesium alloy. The topcoat was a powder coating based on acrylic resin, the main ingredient of which was glycidyl methacrylate. Because of the presence of epoxy groups, the coating was cured using ultraviolet (UV) radiation (low-temperature technology). The conversion subcoating was produced by plasma electrolytic oxidation (PEO) in an alkaline silicate electrolyte. The synthesized coating system was tested, among others, for microscopic (SEM), adhesive (mesh of cuts), and anticorrosion (EIS). The duplex PEO/UV-curable powder coating showed very good adhesion to the metal and increased the anticorrosion properties of the magnesium substrate, compared to the powder coating produced directly on the magnesium alloy and on an alternative conversion coating (synthesized in the process of chemical zircon phosphating). [ABSTRACT FROM AUTHOR]

As an environment‐friendly powder with good coloring performance, rare earth sulfide is one kind of the important choices to replace cadmium and lead colorants. In particular, γ‐Ce2S3 belongs to rare earth sesquisulfide, which has a bright red color. However, the uncoated γ‐Ce2S3 is easy to decompose and release H2S in a humid or acidic environment, and its air thermal stability is limited to 350°C. In this work, γ‐Ce2S3 powders coated with zinc oxide were prepared by heterogeneous precipitation method, and a dense protective layer was formed by ZnO to improve chemical and thermal stability. Moreover, silicon dioxide was deposited on the surface of the zinc oxide coating using the microemulsion process to strengthen the powder's acid resistance. The double shells structure greatly promoted thermal stability and acid resistance of γ‐Ce2S3 powders. The results showed that rare earth sulfide powders with double shells have good stability for coloring applications. [ABSTRACT FROM AUTHOR]

The aerosol deposition process, involving the impact of solid particles on a substrate at high velocities, is an attractive method for the manufacture of ceramic coatings at room temperature. For process optimisation, it is crucial to select a powder having the appropriate physical characteristics and evaluate the particle flow behaviour during the deposition process. In this study, a powder modification process using high-energy milling and spray drying to improve the applicability of precursor powders was developed and evaluated both numerically and experimentally. A modified aerosol deposition system incorporating a brush-type aerosol generator was employed to maintain the continuity of the aerosol supply and improve the stability of the particle concentration. The deposition efficiency was nearly tripled when using spray-dried granules (0.68%) instead of the as-received powders (0.26%). From tribological measurements, the strongest interfacial bonding was also confirmed for coatings prepared with alumina granules. [ABSTRACT FROM AUTHOR]

Antifouling properties of unmodified kraft lignin for potential use in marine coatings were investigated. The study was based on preliminary findings that pointed toward lignin's efficacy against seawater organisms during laboratory tests. Coatings were formulated that contained lignin as a filler and had a pigment volume concentration above the critical pigment volume concentration. This ensured direct interaction between lignin and seawater organisms, as the lignin particles remained incompletely wetted by the binder. Moreover, all formulations were waterborne to mitigate the release of volatile organic compounds. Despite the initial promise, the antifouling performance of the formulated lignin coatings during field experiments at the CoaST Maritime Test Center was limited, and the anticipated mechanism must be reconsidered. Additionally, it was found that high lignin concentrations, while facilitating organism interaction, compromised the coating's mechanical properties. Nevertheless, the waterborne coating formulation introduced here might provide a foundation for other researchers to further investigate lignin's potential as a bio-based pigment or a filler in coatings. [ABSTRACT FROM AUTHOR]

The present study investigated the effect of mechanical milling on Cr3C2-NiCr coatings deposited using the HVOF spraying method. The milling process was carried out using powder with varying characteristics to produce fine-grained and flaky powders. The milled powder coatings exhibited higher density and reduce porosity, leading to improve surface hardness and bond strength. To evaluate the performance of these coatings, hot corrosion and erosion tests were conducted under controlled conditions. The hot corrosion test was performed in a chloride environment using a vapor-condensed salt mixture (45% NaCl + 55% KCl) at 600 °C for 100 hours, while the erosion test was conducted at room temperature with an impact angle of 90°. The results showed that the milled powder coating demonstrated superior resistance to both corrosion and erosion compared to the unmilled powder coating. Specifically, the corrosion mass product and erosion rate of the milled powder coating were 3.40 mg/cm2 and 0.62 mg/g, respectively, while those of the unmilled powder were 10.07 mg/cm2 and 1.84 mg/g, respectively. This study revealed that the microstructure of powder coating has a significant effect on its erosion and hot corrosion performance. Furthermore, the research investigated the mechanisms responsible for these performances and concluded that the coating's porosity and homogeneous structure can enhance its resistance against both erosion and corrosion. [ABSTRACT FROM AUTHOR]

This paper presents studies on the influence of the chemical structure of (meth)acrylic monomers on the properties of powder coatings based on polyacrylate resins. For this purpose, a wide range of monomers were selected—2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA), n-butyl acrylate (nBA), tert-butyl acrylate (tBA), dodecyl acrylate (DA), ethyl acrylate (EA) and benzyl acrylate (BAZ)—for the synthesis of the polyacrylate resin. The average molecular mass and molecular mass distribution of the synthesized resins were measured by gel permeation chromatography (GPC). The glass transition temperature (Tg) and viscosity of polyacrylate resins were determined by using differential scanning calorimetry (DSC) and a Brookfield viscometer. These parameters were necessary to obtain information about storage stability and behavior during the application of powder clear coatings. Additionally, DSC was also used to checked the course of the low-temperature curing reaction between the hydroxyl group contained in the polyacrylate resin and the blocked polyisocyanate group derived from a commercial agent such as Vestanat B 1358/100. The properties of the cured powder clear coatings were tested, such as: roughness, gloss, adhesion to the steel surface, hardness, cupping, scratch resistance, impact resistance and water contact angle. The best powder clear coating based on the polyacrylate resin L_HEMA/6MMA/0.5nBA/0.5DA was characterized as having good scratch resistance (550 g) and adhesion to the steel surface, a high water contact angle (93.53 deg.) and excellent cupping (13.38 mm). Moreover, its crosslinking density (CD) and its thermal stability was checked by using dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). [ABSTRACT FROM AUTHOR]

The ability to objectively specify surface finish to ensure consistent visual appearance addresses a vital need in surface coating engineering. This work demonstrates how a computational framework, called surface quality and inspection descriptors (SQuID™), can be leveraged to effectively rank different grades of surface finish appearances. ISO 25178-2 areal surface metrics extracted from bandpass-filtered measurements of a set of ten visual smoothness standards taken on a coherent scanning interferometer are used to quantify different grades of powder-coated surface finish. The ability to automatically classify the standard tiles using multi-scale areal texture parameters is compared to parameters obtained from a hand-held gloss meter. The results indicate that the ten different surface finishes can be automatically classified with accuracies as low as 65% and as high as 99%, depending on the filtering and parameters used to quantify the surfaces. The highest classification accuracy is achieved using only five multi-scale topography descriptions of the surface. [ABSTRACT FROM AUTHOR]

When fabricating a metal powder filter with a double-layered pore structure, which includes a microporous layer, by coating flake-shaped powder using the Wet Powder Spray (WPS) process, it is crucial to ensure that the coating is applied parallel to the surface of the metal powder filter. Failure to do so can result in a non-uniform pore structure, leading to a rapid decline in particle filtration efficiency. Therefore, it is necessary to improve the alignment of the coated flake-shaped powder on the filter surface. In this study, a metal powder filter with a double-layered pore structure was fabricated by applying a flake-shaped metal powder coating to a tube-shaped SUS316L powder filter using the WPS process. In order to improve the flake-shaped powder orientation of coating layer, the impact of the rolling process was investigated. The characteristics of the pores were analyzed based on the powder size and the rolling time. The microstructure of the fabricated metal powder filter was observed using an optical microscope, surface roughness, variations in thickness, and air permeability were analysed. [ABSTRACT FROM AUTHOR]

This article presents precautions to be taken when installing and repairing powder-coated messenger wires to prevent corrosion in salt- and sulfur-affected areas. This is the eighty-first article in a series on telecommunication technologies. [ABSTRACT FROM AUTHOR]

The aim of this investigation concerns evaluating the mechanical strength and microhardness values of A356 alloy samples in distinctive heat treatments, including those commonly applied to automotive wheels. It is recognized that A356 and Al-Si-based alloys exhibit considerable versatility across numerous industrial applications. The mechanical behavior obtained is intimately associated with different operational parameters (e.g., cooling rates, solution treatment, quenching, and artificial aging). In this study, a group of samples are quenched at 30, 60 and 80 °C. Another set is quenched and subsequently aged at three different temperatures, i.e., 180, 200, and 220 °C for 5 h, and mechanical responses are compared. Microstructural characterization, X-ray diffraction (XRD) analysis, tensile testing, and microhardness measurements are carried out. Using the Rietveld data and based on the modified Williamson–Hall method, the microstrains, crystallite size, and dislocation densities are calculated. Based on this, the resulting mechanical strengths from distinctive quenching and aging are understood. It was found that there exists a "quasi-optimal range" of operational parameters involving different A356 alloy treatments, which vary depending on the manufacturing route. Considering A356 alloy wheels, the planning of the powder coat treatment before or after T6 treating provides better mechanical properties and ductility. [ABSTRACT FROM AUTHOR]

A chemical coating method to form a core-shell structure was applied to produce ZnO@Ba 0.65 Bi 0.07 Sr 0.245 TiO 3 (ZnO@BBST) relaxing ferroelectric ceramics with high energy storage density. The ZnO@BBST ceramic grain was refined and the structure is dense. Simultaneously, the relaxor behavior of ZnO@BBST was improved due to the synergistic effect of ZnO shell and internal BBST. Ultimately, under the electric field of 320 kV/cm, a energy storage density of 1.91 J/cm3 and an energy storage efficiency of 82 % are obtained in 2 wt% ZnO@BBST, together with fast discharge characteristics(τ 0.9 <1.25 μs) and excellent cycle stability (up to 1 × 105 times). ZnO@BBST ceramics have its unique advantages in the field of ceramic capacitors. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sustainability has increasingly become a cornerstone of the chemical industry. Sustainability metrics include low volatile organic compound (VOC) content, high efficiency, low toxicity, low energy requirements, minimal waste, recyclability, durability, and the use of renewable feedstocks. Powder coatings are well known for zero VOCs, efficient utilization, low toxicity, and recyclability. Powder coating technologists have recently ventured into the use of renewable feedstocks to synthesize binder systems. Bio-based compounds have been successfully used to produce highly sustainable powder coatings. This review presents recent research on new binder components designed for powder coatings, including: (poly(limonene carbonate)s; polyester resins; polyamide resins; and crosslinking agents (urethane-acrylates, blocked polyisocyanates). The applications of bio-based materials in powder coatings are also highlighted in this review. [ABSTRACT FROM AUTHOR]

Copyright of Coatings & Protection / Tuceng yu Fanghu is the property of Coating & Protection Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coatings & Protection / Tuceng yu Fanghu is the property of Coating & Protection Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Environmentally friendly powder coatings which have the advantages of being VOC-free, low-cost, and high-efficiency with a high recovery rate have been attracting increasing research attention. The introduction of antibacterial agents into the powder coatings endows them with a capacity to kill bacteria and viruses on the surface of objects; additionally, this enables them to inhibit the indirect transmission of pathogenic microorganisms. Silver, possessing broad-spectrum, strong, and stable antibacterial properties, is considered to be a promising antibacterial material for use in coating applications. Carrier materials for active silver play an important role in its activity and stability. However, there is a lack of systematic studies on the effects of different types of carriers in such coating systems, especially in green powder coating systems. In this paper, we investigated two types of carriers for active silver agents: zeolite, i.e., Linde type A (LTA) zeolite and Y-type zeolite; clay-based materials, i.e., montmorillonite and vermiculite. All the agents showed high antibacterial activity, with antibacterial rates of over 99% as compared to commercial agents. Among the four agents, the Ag-LTA zeolite antimicrobial agent showed a reduction rate of over 99.99%; additionally, it maintained a reduction rate of 99% after seven washing cycles. Thus, this agent was demonstrated to have the highest effectiveness and high durability; these features can be attributed to the high silver content and small particle size. The LTA zeolite also provides a protective effect for silver ions, protecting them from reduction, due to the restriction of elemental silver formation within the confined interior space of the α-cage structure. The Y-type zeolite antimicrobial agent exhibited a slightly lower antimicrobial performance due to its higher silicon-to-aluminum ratio and its lower cation exchange capacity. Comparatively, antimicrobial agents utilizing clay-based carriers have lower cation exchange capacity, resulting in poorer antimicrobial effectiveness than zeolite carriers. In addition, silver loaded on clay-based materials is prone to detach from the carrier and undergo a reduction reaction, making the coating yellowish in color. This study first provides information on the roles of different types of carriers in powder coating systems; then, this information guides the selection of carriers for active silver for the development of efficient antimicrobial agents and coatings. [ABSTRACT FROM AUTHOR]

The powder surface coating technology might endow the powder with new physical and chemical properties. By electrophoretic deposition technology, diamond powder was modified on the surface coating of WC powders. The core-shell structure of diamond and the coating between diamond powder and WC powder were analyzed by different characterization methods. The influences of diamond powder content on coating effectiveness were studied, and the bonding strength among powders was compared under different coating processes. The results show that when the mass ratio of WC powder to diamond powder is as 6 : 1, the coating effectiveness is the best. The strong bonding force among the modified powders comes from the chemisorption formed by covalent bonds such as COO-W and C-O-W and the physical adsorption formed by van der Waals force. [ABSTRACT FROM AUTHOR]

Given the environmental benefits, poly(vinylidene fluoride) (PVDF)‐based composite powder coating was developed without using any harmful solvent. However, it still remains poor adhesion to substrates and low compatibility to acrylic resin issues. To address these challenges, PVDF was grafted with glycidyl methacrylate (GMA) through a facile and scalable reactive extrusion method. The resulting product, PVDF‐g‐GMA, was then mixed with different contents of polymethyl methacrylate (PMMA), and the mixing was sprayed onto aluminum substrates. The PVDF‐g‐GMA/PMMA powder coating shows the excellent adhesion and corrosion resistance, particularly when the PMMA content is 30 wt%, owning to the good compatibility of PVDF‐g‐GMA and PMMA. This work opens up a new possibilities for the development of advanced composite powder coatings with improved performance characteristics. [ABSTRACT FROM AUTHOR]

Microwave power absorption by a two‐layer system deposited on a metallic surface is studied in the experimental setup emulating the response to a radar signal. Layers containing hexaferrite and iron powder in a dried paint of thickness under 1 mm are used. The data is analyzed within a theoretical model derived for a bilayer system from the transmission line theory. A good agreement between experimental and theoretical results is found. The advantage of using a bilayer system over a single‐layer system is demonstrated. How the maximum microwave absorption (minimum reflection) can be achieved through the optimization of the filling factors and thicknesses of the two layers is shown. [ABSTRACT FROM AUTHOR]

A direct current triboelectric nanogenerator (DC‐TENG) based on corona discharge has a high efficiency in collecting electrification charges. However, enhancing the constant current output with an ultra‐low crest factor and average power density of DC‐TENG through a rational structure design is still a great challenge. Herein, a novel ternary dielectric electrification TENG (TDE‐TENG) is proposed with Kapton/electrode/Polytetrafluoroetylene (PTFE) on the slider and Polyurethane (PU) modified by PTFE powder on the stator. The PTFE powder is coated on PU film to regulate its triboelectricity and realize its electropositivity/electronegativity under friction with PTFE/Kaption, which is an important discovery for tribomaterials. The collecting electrode on the slider can synergistically capture charges generated from its adjacent two tribo‐materials. This structure of TDE‐TENG can further realize multiple unit integration to fully capture the tribo‐charges. TDE‐TENG achieves a charge density of 5.5 mC m−2 and a constant current output with an ultra‐low crest factor of 1.02 at 30 rpm. Moreover, the sliding TDE‐TENG has an average power density of 12.4 W m−2, which breaks the record for all sliding DC‐TENGs. The direct connection of the 4‐unit TDE‐TENG with the PMC generates an output charge of 1.17 mC s−1. This work provides a novel strategy for enhancing DC‐TENG output performance. [ABSTRACT FROM AUTHOR]

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Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

When the thickness of the wave-absorbing material is low, there exists the problem of the narrow wave-absorbing frequency band, making it difficult to regulate the position of the wave-absorbing peak. In this study, FeNi@SrFe-MOF composite powders were synthesized using a hydrothermal method and a liquid-phase reduction method. The composite powder was spherical, with a particle size of about 50 μm–60 μm; the core layers of the powders were porous SrFe-MOF powders with permanent magnetization, and the outer layers were FeNi alloy nano-powder coatings with a particle size of 100 nm–120 nm, which took into account both the soft magnetization and the permanent magnetization properties of the composite powders. Additionally, a directional magnetic field was applied to the powder coating. By regulating the intensity and direction of the magnetic field, the electromagnetic parameters of the composite powder coating underwent sensitive changes, allowing for the precise regulation of the electromagnetic wave absorption performance of the composite powders. With the increase in magnetic field intensity, the ε′ value decreased significantly. The ε′ values were 8.56–7.35 for H453mT and 6.73–6.12 for H472mT. When no magnetic field was applied, the Snoke limit frequency of the μ′ value was 6.0 GHz. When the magnetic field intensity increased, the Snoke limit frequency of the μ′ value increased from 6.0 GHz, without the magnetic field, to 8.3 GHz; the Snoke limit of the composite powders was shattered. After the H453mT magnetic field regulation treatment, the powder coating exhibited good impedance matching characteristics with air. When the magnetic field intensity was 453mT and the thickness of the composite powders coating was 3.5 mm, the composite powders coating showed the strongest absorption peak when the R-value was −59 dB at 7.8 GHz, and the effective absorption bandwidth reached 3.2 GHz, exhibiting superb absorbent qualities. The wave absorption property of the coating can be sensitively changed by the magnetic field regulation treatment at the condition without changing the powder structure or coating structure, which provides a new strategy for the regulation of the wave absorption property and has broad application prospects. [ABSTRACT FROM AUTHOR]