Science and Technology Production
Article
Authorship
Mariano Escobar
;
Sergio Moreno
;
Roberto J. Candal
;
MARCHI, MARIA CLAUDIA
;
Alvaro Caso
;
Pablo Polosecki
;
Gerardo H. Rubiolo
;
Silvia Goyanes
Date
2007
Publishing House and Editing Place
ELSEVIER SCIENCE BV
Magazine
APPLIED SURFACE SCIENCE,
vol. 254
(pp. 251-256)
ELSEVIER SCIENCE BV
Summary
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The effect of acetylene partial pressure on the structural and morphological properties of multi-walled carbon nanotubes (MWCNTs) synthesized by CVD on iron nanoparticles dispersed in a SiO2 matrix as catalyst was investigated. The general growing conditions were: 110 cm3/min flow rate, 690 °C synthesis temperature, 180 Torr over pressure and two gas compositions: 2.5% and 10% C2H2/N2. The catalyst and nanotubes were characterized by HR-TEM, SEM and DRX. TGA and DTAwere also carried out to ...
The effect of acetylene partial pressure on the structural and morphological properties of multi-walled carbon nanotubes (MWCNTs) synthesized by CVD on iron nanoparticles dispersed in a SiO2 matrix as catalyst was investigated. The general growing conditions were: 110 cm3/min flow rate, 690 °C synthesis temperature, 180 Torr over pressure and two gas compositions: 2.5% and 10% C2H2/N2. The catalyst and nanotubes were characterized by HR-TEM, SEM and DRX. TGA and DTAwere also carried out to study degradation stages of synthesized CNTs. MWCNTs synthesized with low acetylene concentration are more regular and with a lower amount of amorphous carbon than those synthesized with a high concentration. During the synthesis of CNTs, amorphous carbon nanoparticles nucleate on the external wall of the nanotubes. At high acetylene concentration carbon nanoparticles grow, covering all CNTs’ surface, forming a compact coating. The combination of CNTs with this coating of amorphous carbon nanoparticles lead to a material with high decomposition temperature.
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Key Words
Carbon nanotubesX-ray diffractionIron catalystsAcetylene decompositionThermal analysisChemical vapor depositionScanning and transmission electron microscopy