Characterization of diffusion flame synthesis of single-walled carbon nanotubes

C. J. Unrau, R. L. Axelbaum, P. Biswas, P. Fraundorf

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Single-walled carbon nanotube (SWNT) formation in a diffusion flame is analyzed for catalyst particle composition and SWNT growth rate. A typical fuel/air diffusion flame is sooty and not suitable for nanotube growth but by using a combination of oxygen-enrichment and fuel dilution, fuel oxidation is favored over pyrolysis and subsequent soot formation. Furthermore, an inverse flame configuration is used to create a flame environment that is favorable for SWNT growth. The optimum flame conditions and location for SWNT growth as well as the optimum catalyst particle composition were determined in situ using a scanning mobility particle sizer (SMPS) to measure the size distribution of the flame. The optimum catalyst particle composition was determined by comparing the size distributions of three flames with the same temperature but different levels of oxygen-enrichment. Increasing oxygen-enrichment oxidized the catalyst particles from iron to iron(II) oxide to iron(III) oxide with SWNTs being produced primarily from iron(II) oxide. Thus, oxygen-enrichment can be used to eliminate soot formation and to optimize catalyst particle composition. Finally, the SMPS and flame velocity measurements were used to measure growth rate. SWNTs were found to form in the post-flame region and grow at a maximum rate of over 100 μm/s.

Original languageEnglish (US)
Title of host publication5th US Combustion Meeting 2007
PublisherCombustion Institute
Number of pages14
ISBN (Electronic)9781604238112
StatePublished - 2007
Externally publishedYes
Event5th US Combustion Meeting 2007 - San Diego, United States
Duration: Mar 25 2007Mar 28 2007

Publication series

Name5th US Combustion Meeting 2007


Conference5th US Combustion Meeting 2007
Country/TerritoryUnited States
CitySan Diego

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Physical and Theoretical Chemistry
  • Mechanical Engineering


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