These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Synthesis of multiwalled carbon nanotubes on fly ash derived catalysts.
    Author: Dunens OM, MacKenzie KJ, Harris AT.
    Journal: Environ Sci Technol; 2009 Oct 15; 43(20):7889-94. PubMed ID: 19921910.
    Abstract:
    Carbon nanotubes (CNTs) are an allotrope of carbon with unique properties that make them potentially useful in a vast range of applications. However, CNTs are predominantly produced using expensive and/or nonrecyclable catalyst supports, e.g., mesoporous silica and alumina. In this work, coal combustion fly ash, a bulk waste product with limited uses, was impregnated with iron nitrate and successfully used as a substrate to produce industrial grade multiwalled carbon nanotubes (MWNTs) by fluidized bed chemical vapor deposition. CNTs were analyzed using thermogravimetric analysis, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. The most successful catalyst trialed at 650 degrees C using ethylene as a carbon source was a 5 wt % Fe fly ash catalyst, which produced a CNT yield in respect to metal loading of approximately 82.5%. The MWNTs had outer diameters of between 12 and 20 nm with a reasonable degree of wall graphitization (I(G)/I(D) of 1.17). Advantages of utilizing fly ash as a catalyst support are its availability at low cost at the megaton scale, its high thermal stability, and suitability for use in industrial fluidized bed reactors. Potential applications for the fly ash produced CNTs include use in composite materials.
    [Abstract] [Full Text] [Related] [New Search]