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Structural Evolution in Glassy Carbon Investigated Based on the Temperature Dependence of Young’s Modulus
As a non-graphitized carbon material, possessing exceptional hardness and chemical inertness, glassy carbon (GC) is often synthesized through the pyrolysis method, which includes a compression procedure of powdered precursor materials, thus increasing the costs for production of glassy carbon at an...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10343330/ https://www.ncbi.nlm.nih.gov/pubmed/37445108 http://dx.doi.org/10.3390/ma16134794 |
Sumario: | As a non-graphitized carbon material, possessing exceptional hardness and chemical inertness, glassy carbon (GC) is often synthesized through the pyrolysis method, which includes a compression procedure of powdered precursor materials, thus increasing the costs for production of glassy carbon at an industrial scale. Direct preparation of GC via pyrolysis of bulk precursors is a low-cost approach but encounters challenges arising from an insufficient knowledge of carbon structure formation. In order to solve this problem, a new analysis of the temperature-dependent variation in Young’s modulus of GC obtained by the pyrolysis of phenolic resin at 1000 °C, utilizing the impulse excitation technique (IET), was performed. Our findings demonstrate that there is a critical temperature range of 500–600 °C where pyrolysis leads to the most significant density change and GC is formed as a result. When GC samples are heated again, a significant structural reformation occurs in the same temperature range. It causes a decrease in stiffness, especially at heating rates >3 °C/min, and an interesting restorative effect–increase in stiffness when a GC sample is annealed at temperatures of 500–550 °C. These results bring important implications for the direct formation of large amounts of glassy carbon using bulk precursors. |
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