| 1. |
|
|
| 2. |
|
|
| 3. |
- Grinchuk, P. S., et al.
(author)
-
Effect of technological parameters on densification of reaction bonded Si/SiC ceramics
- 2018
-
In: Journal of the European Ceramic Society. - : Elsevier Ltd. - 0955-2219 .- 1873-619X. ; 38:15, s. 4815-4823
-
Journal article (peer-reviewed)abstract
- Si/SiC composite ceramics was produced by reaction sintering method in process of molten silicon infiltration into porous C/SiC preform fabricated by powder injection molding followed by impregnation with phenolic resin and carbonization. To optimize the ceramics densification process, effect of slurry composition, debinding conditions and the key parameters of all technological stages on the Si/SiC composite characteristics was studied. At the stage of molding the value of solid loading 87.5% was achieved using bimodal SiC powder and paraffin-based binder. It was found that the optimal conditions of fast thermal debinding correspond to the heating rate of 10 °C/min in air. The porous C/SiC ceramic preform carbonized at 1200 °C contained 4% of pyrolytic carbon and ∼25% of open pores. The bulk density of Si/SiC ceramics reached 3.04 g/cm3, silicon carbide content was 83–85 wt.% and residual porosity did not exceed 2%.
|
|
| 4. |
- Shahzadi, I., et al.
(author)
-
Hydrothermal Synthesis of Fe-Doped Cadmium Oxide Showed Bactericidal Behavior and Highly Efficient Visible Light Photocatalysis
- 2023
-
In: ACS Omega. - 2470-1343. ; 8:33, s. 30681-30693
-
Journal article (peer-reviewed)abstract
- Cationic dyes presentin industrial effluents significantlyreducethe effectiveness of remediation operations. Considering the terribleimpact of these pollutants on environment and biodiversity, investigatingstrategies to remove potentially harmful compounds from water is becomingan increasingly intriguing issue. In this work, we employed a simplehydrothermal technique to synthesize Fe-doped CdO (2, 4, and 6 wt%) nanostructures and assessed their efficacy in degrading methyleneblue (MB) dye and inhibiting the growth of Staphylococcusaureus and Escherichia coli, respectively. Structural, morphological, and optical characterizationof produced nanomaterials was also performed using X-ray diffraction,TEM, and UV absorption spectra. The photocatalytic decomposition ofMB was significantly enhanced (58.8%) by using Fe (6 wt %)-doped CdOcatalysts for 80 min under irradiation. In addition, 2.05-5.05mm inhibitory zones were seen against Gram-positive bacteria (S. aureus), whereas the range for Gram-negative bacteria(E. coli) was 1.65-2.75 mm.These nanostructures were shown to be very effective inhibitors ofbeta-lactamase, d-alanine-d-alanine ligase B, andfatty acid synthase inhibitor by in silico molecular docking investigations.
|
|
| 5. |
- Solovei, D. V., et al.
(author)
-
Synthesis of Reinforced Ceramic Matrix Composite Based on SiC and Nanocarbon Mesh
- 2019
-
In: Journal of Engineering Physics and Thermophysics. - : Springer New York LLC. - 1062-0125 .- 1573-871X. ; 92:4, s. 1016-1024
-
Journal article (peer-reviewed)abstract
- Most modern matrix composite materials employ a variety of carbon nanofillers to improve their mechanical, electrical, and functional properties. Nanofillers are separately implanted into the initial ceramic matrix, which complicates the composite manufacturing technology and increases the final cost. In this work, the synthesis of nanocarbon fillers was carried out using high-temperature (1200°C) pyrolysis of phenolic resin directly inside the silicon carbide matrix. This results in the formation of a continuous 3D nanocarbon mesh uniformly binding and reinforcing the final product throughout the volume. The nanocarbon filler synthesized in the SiC matrix contains two allotropic carbon forms: nanographite and nanofibers. The study of the features of the carbon structure and morphology showed that during the pyrolysis the multilayered nanographite structures had been formed on the surface of SiC grains of average crystallite size equal to 20–35 nm. In the matrix pores, carbon nanofibers a few micrometers in length and 20–40 nanometers in diameter are synthesized. The reiteration of the phenolic resin impregnation–pyrolysis cycle increased the free carbon content from 4 to 7 wt.% for once and twice impregnated and pyrolyzed samples, respectively, and the Young's modulus, from 50.7 to 94.3 GPa. The obtained carbon content and structure are appropriate to produce C/SiC composite for application of ceramics and electrodes.
|
|
| 6. |
- Alshahrani, M. A.M., et al.
(author)
-
High-Temperature Hydrogen Attack on 2.25Cr-1Mo Steel: The Roles of Residual Carbon, Initial Microstructure and Carbide Stability
- 2022
-
In: Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science. - : Springer Science and Business Media LLC. - 1073-5623. ; 54, s. 3682-
-
Journal article (peer-reviewed)abstract
- High temperature hydrogen attack is a damage mechanism that occurs in critical steel components in petrochemical plants and refineries when the hydrogen penetrates the steel and reacts with the carbides within to produce pores containing methane. With the motivation of understanding the role of carbide stability on the reaction with hydrogen, samples of a classic 214Cr-1Mo steel were subjected to a variety of heat treatments that generate a corresponding variety of precipitates, prior to exposure to high-pressure hydrogen in an autoclave. Using quantitative carbide, porosity and microstructural characterisation, it has been possible to demonstrate the roles of four variables: (a) the carbon residue present in the ferrite; (b) the non-equilibrium chemical composition of carbide; (c) the fraction of the carbide that is closest to the thermodynamic equilibrium state and (d) the initial microstructural state, i.e., whether it is martensitic or bainitic prior to heat treatment.
|
|
| 7. |
- Li, Shangyu, et al.
(author)
-
Tethered Small-Molecule Acceptors Simultaneously Enhance the Efficiency and Stability of Polymer Solar Cells
- 2023
-
In: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095. ; 35
-
Journal article (peer-reviewed)abstract
- For polymer solar cells (PSCs), the mixture of polymer donors and small-molecule acceptors (SMAs) is fine-tuned to realize a favorable kinetically trapped morphology and thus a commercially viable device efficiency. However, the thermodynamic relaxation of the mixed domains within the blend raises concerns related to the long-term operational stability of the devices, especially in the record-holding Y-series SMAs. Here, a new class of dimeric Y6-based SMAs tethered with differential flexible spacers is reported to regulate their aggregation and relaxation behavior. In their polymer blends with PM6, it is found that they favor an improved structural order relative to that of Y6 counterpart. Most importantly, the tethered SMAs show large glass transition temperatures to suppress the thermodynamic relaxation in mixed domains. For the high-performing dimeric blend, an unprecedented open circuit voltage of 0.87 V is realized with a conversion efficiency of 17.85%, while those of regular Y6-base devices only reach 0.84 V and 16.93%, respectively. Most importantly, the dimer-based device possesses substantially reduced burn-in efficiency loss, retaining more than 80% of the initial efficiency after operating at the maximum power point under continuous illumination for 700 h. The tethering approach provides a new direction to develop PSCs with high efficiency and excellent operating stability.
|
|
