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Properties of ta-C coatings prepared by pulsed cathodic arc source at various distances
摘要： Tetrahedral amorphous carbon (ta-C) coatings have been prepared on silicon substrates by the pulsed cathodic arc source. For the limitation of the heat flux of the carbon plasma to the sample, the diaphragm of 27 mm diameter has been used. The deposition process has been carried out at three different distances between the arc source and the substrate: 150, 215 and 265 mm. The properties of ta-C coatings have been studied by Raman spectroscopy and dynamic nanoindentation techniques. The analysis of Raman spectra parameters has revealed that the concentration of ordered aromatic rings in Csp2 cluster decreases with distance between the arc source and the substrate while the concentration of chain groups increases. Nanoindentation has shown the decrease in nanohardness and Young's modulus with the distance. Nanohardness value falls from 21 GPa to 16 GPa and Young's modulus value goes down from 197 GPa to 177 GPa. So, it’s possible to control the formation of ta-C coatings structure by changing distance between the pulsed cathodic arc source and the substrate.
关键词： ta-C coatings,nanohardness,Young's modulus,pulsed cathodic arc source,nanoindentation,Raman spectroscopy
更新于2025-09-09 09:28:46
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Investigation of reinforced performance of modified graphene oxide/high solid content polysiloxane nanocomposite coating films
摘要： Graphene oxide was modi?ed using long-chain silicone. The modi?ed graphene oxide (MGO) was obtained with a broader spacing of layers (1.45 nm) which means more bene?cial to polysiloxane entering into the laminates of MGO sheets. Then, MGO sheets were combined with polysiloxane which synthesized without any organic solvent to prepare nanocomposite coatings via cross-linking curing reaction. The solid content of polysiloxane can be reached up to 86%. Due to strong interfacial interaction and synergistic reinforcing between MGO sheets and polysiloxane, when blended with 1.00 wt% of MGO, the micro-hardness and elastic modulus of coating ?lms were increased by 57% and 24% comparing with pure polysiloxane coating ?lm, respectively. Subsequently, a 48% improvement of macro-scratch resistance can be achieved. Simultaneously, MGO/polysiloxane coating ?lm showed excellent wear resistance due to the unique two-dimensional geometry and low frictional coef?cient of MGO sheets at work in homogeneous dispersion system.
关键词： Polysiloxane,Scratch resistance,Wear resistance,Nanocomposite coatings,Graphene oxide
更新于2025-09-09 09:28:46
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[IEEE 2018 International Conference Laser Optics (ICLO) - Saint Petersburg, Russia (2018.6.4-2018.6.8)] 2018 International Conference Laser Optics (ICLO) - Anisotropic optical interference coatings for polarization control in high-power lasers
摘要： Optical anisotropy played a crucial role in development of advanced optical systems. In this study, a novel multi-layer approach of high band-gap birefringent coatings was proposed and investigated. Zero-order thin film retarders and normal incidence polarizers based on all-silica nanostructures are fabricated by oblique angle deposition process. Low optical losses and the potential to withstand high laser fluence in nanosecond regime at 355 nm wavelength for both elements were demonstrated.
关键词： waveplates,polarizers,nanostructured coatings,high-power lasers
更新于2025-09-09 09:28:46
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Role of water in the sol-gel synthesis of yttrium monosilicate
摘要： Yttrium monosilicate (YMS) is a candidate environmental barrier coating material.It is a line compound, and its synthesis requires strict stoichiometric control of the starting materials. In this work, YMS was synthesised by the sol-gel method. Yttrium oxide and tetraethyl orthosilicate (TEOS) were used as precursors. The ratio of water to ethanol was varied to study the role of water in the formation of phase-pureYMS. The formation of secondary phases during synthesis was attributed to the complex interaction of TEOS with water in the presence of ethanol. It was seen that water and ethanol play a significant role in aqueous sol-gel processes involving silica than merely being present as solvents. The results are helpful in identifying the suitable sol-gel parameters for the synthesis of phase-pure yttrium monosilicate.
关键词： Environmental barrier coatings (EBC),Sol-gel synthesis,yttrium monosilicate (YMS)
更新于2025-09-09 09:28:46
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Electrical and Mechanical Properties of CeO2-Based Thin-Film Coatings Obtained by Electrophoretic Deposition
摘要： Nanometer Ce0.8(Sm0.75Sr0.20Ba0.05)0.2O2 – δ powder with mean nanoparticle size of 15 nm has been obtained by laser evaporation of a solid-phase target followed by condensation. The nanopowder has been used to prepare suspensions for electrophoretic deposition in a mixed isopropanol : acetyl acetone = 50 : 50 vol % disperse medium offering the unique property of self-stabilization. Optimal conditions for electrophoretic deposition have been found, and uniform thin-film electrolytic coatings have been formed on a La2NiO4 cathodic carrier substrate (12–15% porosity). It has been shown that the resulting electrolyte offers a high adhesivity and has, after sintering at 1400°C, a compact granular structure with grains from 1 to 8 μ m in size. The conductivity of the 2-μ m-thick electrolyte equals 0.1 S/cm at 650°C.
关键词： solid oxide fuel cells,nanopowder,electrophoretic deposition,conductivity,CeO2-based thin-film coatings
更新于2025-09-09 09:28:46
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Hollow Plasma-Sprayed Spherical Nanostructured Titania Feedstock for Photocatalytic Applications
摘要： There have been persistent challenges in thermal spraying of nanoparticles feedstock for making nanostructured coatings with desired mechanical strength. Here we report fabrication of nanostructured titania coatings by atmospheric plasma spraying of hollow titania spheres, and microstructures and photocatalytic activities of the coatings are examined. The hollow microspheres are * 50 lm in diameter and possess a mesoporous shell of 1-3 lm in thickness. The coatings show micro-nano hybrid structures with well-retained titania nanoparticles and agglomerated granules. High anatase content is achieved in the coatings, suggesting that constrained heating of the particles effectively prevents the transformation from anatase to rutile. The spherical characteristics of the organic materials in the feedstock powder play dominant roles in regulating the physicochemical characteristics of the coatings for photocatalytic performances. These results would provide insight into large-scale thermal spray fabrication of nanostructured coatings using appropriately designed hollow spherical powder.
关键词： nanostructured coatings,plasma spray,titania nanoparticles,photocatalytic performances,hollow microspheres
更新于2025-09-09 09:28:46
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Photopolymerization of Ionic Liquids – A Mutually Beneficial Approach for Materials Fabrication
摘要： Photopolymerization is a convenient fabrication technique with the power to control the polymerization in both time and space, be solvent free, and use simple equipment to initiate the polymerization reaction. These features are conditional on use of liquid monomers and crosslinkers that do not require solvent for processing. One class of compounds that provides these opportunities are ionic liquid (IL) monomers, which possess negligible vapour pressure and are free-flowing liquids at room temperature. For these reasons, ILs and photopolymerization are complementary to each other towards the fabrication of electrolyte materials by circumventing the innate difficulty in processing PILs as melts. Instead, the electrolyte polymer is formed as a crosslinked material directly where it will be used. In this review, we outline recent work demonstrating the key benefits of this unlikely marriage, including formulation design, applications in coatings, membranes, and others.
关键词： ionic liquids,membranes,coatings,UV-curing,Photopolymerization
更新于2025-09-09 09:28:46
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Effect of current density and ZnO nano particles influence on the microstructure and mechanical strengthening properties of Zn-TiO<sub align="right">2-ZnO alloys at constant deposition time
摘要： In this work, the effect of current density and particle loading on microstructure and mechanical properties of Zn-TiO2-ZnO nanocomposite produced via electrocodeposition are investigated. The morphological characteristics of the nano-composite coatings were characterised by scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS). Mechanical examination was carried out using Dura scan micro-hardness tester and CERT UMT-2 multi-functional tribological tester. The corrosion properties were evaluated using linear polarisation technique in 3.5% NaCl. The result showed that the coatings exhibited good stability and the quantitative particle loading significantly improved the micro-structural properties of the coating. It is also noticed that the hardness performance and corrosion resistance of the coatings were significantly impacted with over 70% improvement as against the as-received samples.
关键词： Zn-TiO2-ZnO,electrocodeposition,coatings,corrosion resistance,nanocomposite
更新于2025-09-09 09:28:46
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Determination of interfacial fracture energy for 'pop-in' delaminations in a glass-epoxy system using the indentation method
摘要： The adhesion of coatings often controls the performance of the substrate-coating system. Certain engineering applications require an epoxy coating on a brittle substrate to protect and improve the performance of the substrate. Interfacial adhesion measurements of such systems provide a quantitative metric of that performance. Indentation experiments were performed to induce interfacial delaminations in a glass substrate-epoxy coating system. Delamination loads and radii were measured and applied to an analytical solution originally developed by Rosenfeld et al. (1990) to estimate the interfacial fracture energy of the substrate-coating adhesive bond. Results suggest an interfacial bond strength far exceeding that of similar previously studied glass-epoxy systems.
关键词： bonding,indentation,glass,coatings,epoxy,interfaces,fracture energy,adhesion
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Waikoloa Village, HI, USA (2018.6.10-2018.6.15)] 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Fundamental Characterization of Anti-Soiling Coatings for PV Glass: Application of Small-Angle X-ray Scattering
摘要： When dust and other particulates accumulate on the surface of solar modules, the efficiency of these soiled modules is significantly reduced. Soiling is especially problematic in regions with little rain, where water resources for cleaning modules are scarce. To combat this issue, anti-soiling coatings, on the top-surface of solar modules, are beginning to enter the market. However, limited understanding of anti-soiling mechanisms and uncertainty in their durability has limited their deployment. Porous coatings are anticipated to discourage soiling because their rough surfaces reduce the strength and probability of dirt-to-coating bonds. However, the evolution of this morphology through soiling cycles is largely unknown. Here we present the use of small angle X-ray scattering (SAXS) to monitor the morphology of pristine and soiled, industry-sourced coatings. Initial soiling tests are performed using a standardized soil (AZ road dust) in the lab. This work demonstrates the effectiveness of SAXS in monitoring coating morphology despite the presence of soil surface layers. The capability of SAXS studies to be performed under various temperature, humidity, and soiling conditions sets it apart as a strong characterization tool for developing the understanding of functionality and degradation mechanisms of anti-soiling coatings for PV glass.
关键词： soiling,anti-soiling,materials forensics,small-angle X-ray scattering,anti-reflection,PV glass,coatings,self-cleaning
更新于2025-09-09 09:28:46