Synthesis of Carbon Nano-Structures in Partially-Premixed Jet Flames
| Autor: | Fang-Chi Huang, 黃芳琪 |
|---|---|
| Rok vydání: | 2010 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 98 Combustion synthesis of carbon nano-structures using ethylene-air partially-premixed jet flames and a catalytic Ni substrate was investigated. In the experiments, the injection velocity of fuel-air mixture was kept constant. The influences of sampling position, gas temperature and concentration distributions on the synthesis of carbon nanostructures were examined. The results showed that the increase of fuel concentration leads to an increase of flame height and a wider range of yellow flame (sooty zone). Additionally, a quantity of carbon nano-onions was synthesized at Z = 40 ~ 60 mm for ethylene concentrations of 15.1%, 15.7% and 16.3%; however, only little carbon nanostructure was synthesized at Z = 70 mm because the temperature was too high. It has been verified that the key parameters influencing the formation and yield of CNOs were carbon sources (mainly both the CO and C2H2 concentrations), and heat source (suitable temperature range around 970 ~ 1300 ℃). High-resolution transmission electron microscopy (HR-TEM) and scanning electron microscopy (SEM) images confirmed the presence of spherical carbon nano-onions with diameters ranging from 20 to 40 nm. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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