Iron deposition on multi-walled carbon nanotubes by fluidized bed MOCVD for aeronautic applications
Résumé
The fluidized bed MOCVD process has been studied in order to uniformly deposit iron nanoparticles on the outer surface of multi-walled carbon nanotubes (MWCNTs) tangled in balls of 388 μm in diameter. Using ferrocene as organometallic precursor at atmospheric pressure, various reactive atmospheres of deposition (under N2 , air and H2 ) and an ozone O3 surface pre-treatment of MWCNTs were tested. Around 10 g Fe/100 g MWNCTs were deposited during each run. Under N2 at 650 °C on the raw MWCNTs, nanoparticles formed of Fe and Fe3 C were deposited which have catalyzed the formation of carbon nanofibers (CNFs). 20 h of ozone (O3 ) pre-treatment improved the number and distribution of iron nanoparticles but without increasing the surface coverage of nanotubes. A more intense amorphous carbon deposit also appeared. Under H2 at 550 °C, the amorphous carbon was partly eliminated but fewer iron nanoparticles were present. Under air at 450 °C, a part of the MWCNTs was lost and a Fe2 O3 shell covered each remaining MWCNTs ball. New works are in progress to increase more markedly the surface reactivity of MWCNTs and to deposit pure iron.
Mots clés
Amorphous carbon
Atmospheric pressure
Deposition
Deposits
Fluidization
Fluidized bed process
Fluidized beds
Iron
Nanoparticles
Organometallics
Ozone
Surface treatment
Yarn
Aeronautic applications
Ferrocenes
Iron nanoparticles
Organometallic precursors
Reactive atmospheres
Surface coverages
Surface pre-treatments
Surface reactivity
Multiwalled carbon nanotubes (MWCN)
Domaines
Physique [physics]
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