Synthesis of Silicon Carbide Powders from Methyl-Modified Silica Aerogels
| Autor: | Hae-Jin Hwang, Kyoung-Jin Lee, Se Won Baek, Young Hun Kim, Yanggu Kang |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
silicon carbide (SiC)
carbothermal reduction Morphology (linguistics) Materials science aerogel chemistry.chemical_element 02 engineering and technology lcsh:Technology 01 natural sciences Carbide lcsh:Chemistry chemistry.chemical_compound Carbothermic reaction 0103 physical sciences Silicon carbide General Materials Science lcsh:QH301-705.5 Instrumentation Quartz 010302 applied physics Fluid Flow and Transfer Processes lcsh:T Process Chemistry and Technology surface methyl (-CH3) group General Engineering Aerogel silica (SiO2) 021001 nanoscience & nanotechnology lcsh:QC1-999 Computer Science Applications lcsh:Biology (General) lcsh:QD1-999 Chemical engineering chemistry lcsh:TA1-2040 Agglomerate lcsh:Engineering (General). Civil engineering (General) 0210 nano-technology Carbon lcsh:Physics |
| Zdroj: | Applied Sciences Volume 10 Issue 18 Applied Sciences, Vol 10, Iss 6161, p 6161 (2020) |
| ISSN: | 2076-3417 |
| DOI: | 10.3390/app10186161 |
| Popis: | &beta silicon carbide (SiC) powders were synthesized by the carbothermal reduction of methyl-modified silica aerogel/carbon mixtures. The correlations between the phase evolution and morphologies of the SiC powders and the C/SiO2 ratio were investigated. At a C/SiO2 ratio of 3, &beta SiC formed at 1425 ° C and single-phase SiC powders were obtained at 1525 ° C. The methyl groups (-CH3) on the silica aerogel surfaces played important roles in the formation of SiC during the carbothermal reduction. SiC could be synthesized from the silica aerogel/carbon mixtures under lower temperature and C/SiO2 ratios than those needed for quartz or hydrophilic silica. The morphology of the SiC powder depended on the C/SiO2 ratio. A low C/SiO2 ratio resulted in &beta SiC powder with spherical morphology, while agglomerates consisting of fine SiC particles were obtained at the C/SiO2 ratio of 3. High-purity SiC powder (99.95%) could be obtained with C/SiO2 = 0.5 and 3 at 1525 ° C for 5 h. |
| Databáze: | OpenAIRE |
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