Explaining Bamboo-Like Carbon Fiber Growth Mechanism: Catalyst Shape Adjustments above Tammann Temperature
The mechanism of bamboo-like growth behavior of carbon fibers is discussed. We propose that there is a requirement to have this type of growth: operation above the Tammann temperature of the catalyst (defined as half of the melting point). The metal nanoparticle shape can then change during reaction...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-03-01
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| Series: | C |
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| Online Access: | https://www.mdpi.com/2311-5629/6/2/18 |
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| author | Luís Sousa Lobo Sónia A.C. Carabineiro |
| author_facet | Luís Sousa Lobo Sónia A.C. Carabineiro |
| author_sort | Luís Sousa Lobo |
| collection | DOAJ |
| description | The mechanism of bamboo-like growth behavior of carbon fibers is discussed. We propose that there is a requirement to have this type of growth: operation above the Tammann temperature of the catalyst (defined as half of the melting point). The metal nanoparticle shape can then change during reaction (sintering-like behavior) facilitating carbon nanotube (CNT) growth, adjusting geometry. Using metal nanoparticles with a diameter below 20 nm, some reduction of the melting point (mp) and Tammann temperature (T<sub>Ta</sub>) is observed. Fick’s laws still apply at nano scale. In that range, distances are short and so bulk diffusion of carbon (C) atoms through metal nanoparticles is quick. Growth occurs under catalytic and hybrid carbon formation routes. Better knowledge of the mechanism is an important basis to optimize growth rates and the shape of bamboo-like C fibers. Bamboo-like growth, occurring under pyrolytic carbon formation, is excluded: the nano-catalyst surface in contact with the gas gets quickly “poisoned”, covered by graphene layers. The bamboo-like growth of boron nitride (BN) nanotubes is also briefly discussed. |
| first_indexed | 2024-03-10T20:48:36Z |
| format | Article |
| id | doaj.art-274e71c0a4db488387d5d4004ed3869a |
| institution | Directory Open Access Journal |
| issn | 2311-5629 |
| language | English |
| last_indexed | 2024-03-10T20:48:36Z |
| publishDate | 2020-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | C |
| spelling | doaj.art-274e71c0a4db488387d5d4004ed3869a2023-11-19T20:07:19ZengMDPI AGC2311-56292020-03-01621810.3390/c6020018Explaining Bamboo-Like Carbon Fiber Growth Mechanism: Catalyst Shape Adjustments above Tammann TemperatureLuís Sousa Lobo0Sónia A.C. Carabineiro1LAQV-REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, PortugalLAQV-REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, PortugalThe mechanism of bamboo-like growth behavior of carbon fibers is discussed. We propose that there is a requirement to have this type of growth: operation above the Tammann temperature of the catalyst (defined as half of the melting point). The metal nanoparticle shape can then change during reaction (sintering-like behavior) facilitating carbon nanotube (CNT) growth, adjusting geometry. Using metal nanoparticles with a diameter below 20 nm, some reduction of the melting point (mp) and Tammann temperature (T<sub>Ta</sub>) is observed. Fick’s laws still apply at nano scale. In that range, distances are short and so bulk diffusion of carbon (C) atoms through metal nanoparticles is quick. Growth occurs under catalytic and hybrid carbon formation routes. Better knowledge of the mechanism is an important basis to optimize growth rates and the shape of bamboo-like C fibers. Bamboo-like growth, occurring under pyrolytic carbon formation, is excluded: the nano-catalyst surface in contact with the gas gets quickly “poisoned”, covered by graphene layers. The bamboo-like growth of boron nitride (BN) nanotubes is also briefly discussed.https://www.mdpi.com/2311-5629/6/2/18carbon nanotubesbamboo-like growthboron nitride nanotubeskineticsmechanism |
| spellingShingle | Luís Sousa Lobo Sónia A.C. Carabineiro Explaining Bamboo-Like Carbon Fiber Growth Mechanism: Catalyst Shape Adjustments above Tammann Temperature C carbon nanotubes bamboo-like growth boron nitride nanotubes kinetics mechanism |
| title | Explaining Bamboo-Like Carbon Fiber Growth Mechanism: Catalyst Shape Adjustments above Tammann Temperature |
| title_full | Explaining Bamboo-Like Carbon Fiber Growth Mechanism: Catalyst Shape Adjustments above Tammann Temperature |
| title_fullStr | Explaining Bamboo-Like Carbon Fiber Growth Mechanism: Catalyst Shape Adjustments above Tammann Temperature |
| title_full_unstemmed | Explaining Bamboo-Like Carbon Fiber Growth Mechanism: Catalyst Shape Adjustments above Tammann Temperature |
| title_short | Explaining Bamboo-Like Carbon Fiber Growth Mechanism: Catalyst Shape Adjustments above Tammann Temperature |
| title_sort | explaining bamboo like carbon fiber growth mechanism catalyst shape adjustments above tammann temperature |
| topic | carbon nanotubes bamboo-like growth boron nitride nanotubes kinetics mechanism |
| url | https://www.mdpi.com/2311-5629/6/2/18 |
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