Fluidized bed synthesis of carbon nanotubes – A review

Dasgupta, Kinshuk; Joshi, Jyeshtharaj B.; Banerjee, S.

doi:10.1016/j.cej.2011.05.038

Cited by 124 publications

(53 citation statements)

References 202 publications

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“…Their intrinsic iron content is 1.35 wt%. Their skeleton density is 1.984 kg/m 3 , whereas the grain density of the MWCNT balls was estimated at ~180 kg/m 3 and their untapped density is equal to 90 kg/ m 3 (Coppey, 2013) As found by other authors in the case of nanotubes (Yu et al, 2006;Dasgupta et al, 2011), these MWCNT balls display very good fluidization performance. They exhibit agglomerate particulate fluidization (APF) characteristics between 0 and 3.3 U mf (minimum fluidization velocity) and agglomerate bubbling fluidization (ABF) features beyond 3.3 U mf with high bed expansion (Coppey, 2013).…”

Section: Experimental Set-upmentioning

confidence: 52%

Decoration of Carbon Nanotubes by Semiconducting or Metallic Nanoparticles using Fluidized Bed Chemical Vapour Deposition

Lassègue

Coppey

Noé

et al. 2016

KONA

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Multi-Walled Carbon Nanotubes (MWCNTs) have promising properties that make them potentially useful in a wide variety of applications. The decoration of MWCNTs by metallic or semiconducting nanoparticles aims to intensify some of their properties, in particular thermal and electrical conductivity. Fluidized Bed Chemical Vapour Deposition (FBCVD) is an efficient process to uniformly coat powders by various materials. The coating by SnO 2 , Fe and Si nanoparticles of MWCNTs (Graphistrength ® ) tangled in balls of 360 microns in mean diameter using the FBCVD process has been studied. The influence of some deposition parameters with and without oxidative pre-treatment is analysed on the nucleation and growth of nanoparticles. The various results obtained indicate that the intrinsic surface reactivity of MWCNTs is high enough for CVD precursors involving the formation of highly reactive unsaturated species such as silylene SiH 2 formed from silane SiH 4 pyrolysis in the case of Si deposition. But it must be enhanced for less reactive CVD precursors such as tin tetrachloride SnCl 4 which needs the presence of oxygen-containing groups at the nanotube surface to allow Sn nucleation. So, provided the reactivity of the powder surface and that of the CVD precursors are well tuned, the FBCVD process can uniformly coat the outer surface of MWCNTs by metallic or semiconducting nanoparticles.

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Section: Experimental Set-upmentioning

confidence: 52%

Decoration of Carbon Nanotubes by Semiconducting or Metallic Nanoparticles using Fluidized Bed Chemical Vapour Deposition

Lassègue

Coppey

Noé

et al. 2016

KONA

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“…Nowadays, carbon nanomaterials are being manufactured mainly in the form of single-or multi-walled nanotubes (Dasgupta et al 2011, Prasek et al 2011. In contrast, carbon deposition process (coking, fouling) is highly undesirable in petrochemistry (Benzinger et al 1996) at cracking and dehydrogenation processes and also in the solid oxide fuel cell technology.…”

Section: Introductionmentioning

confidence: 99%

On thermodynamic equilibrium of carbon deposition from gaseous C-H-O mixtures: updating for nanotubes

Jaworski

Zakrzewska

Pianko‐Oprych

2017

Reviews in Chemical Engineering

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AbstractExtensive literature information on experimental thermodynamic data and theoretical analysis for depositing carbon in various crystallographic forms is examined, and a new three-phase diagram for carbon is proposed. The published methods of quantitative description of gas-solid carbon equilibrium conditions are critically evaluated for filamentous carbon. The standard chemical potential values are accepted only for purified single-walled and multi-walled carbon nanotubes (CNT). Series of C-H-O ternary diagrams are constructed with plots of boundary lines for carbon deposition either as graphite or nanotubes. The lines are computed for nine temperature levels from 200°C to 1000°C and for the total pressure of 1 bar and 10 bar. The diagram for graphite and 1 bar fully conforms to that in (Sasaki K, Teraoka Y. Equilibria in fuel cell gases II. The C-H-O ternary diagrams. J Electrochem Soc 2003b, 150: A885–A888). Allowing for CNTs in carbon deposition leads to significant lowering of the critical carbon content in the reformates in temperatures from 500°C upward with maximum shifting up the deposition boundary O/C values by about 17% and 28%, respectively, at 1 and 10 bar.

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“…The growth of tubular structures of better quality strongly depends on the type and flowrate of the carbon precursor [12,[15][16][17][18]. In this study, the crystallinity of CNT structures was elaborated from the TEM micrographs obtained with different spatial resolutions.…”

Section: Resultsmentioning

confidence: 99%

Effect of Gas Flowrate on Nucleation Mechanism of MWCNTs for a Compound Catalyst

Shukrullah

Mohamed

Khan

et al. 2017

Journal of Nanomaterials

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Activation of the catalyst particles during a CVD process can be anticipated from the carbon feeding rate. In this study, Fe 2 O 3 /Al 2 O 3 catalyst was synthesized with uniformly dispersed iron over alumina support for onward production of multiwalled carbon nanotubes (MWCNTs) in a fluidized bed chemical CVD reactor. The effect of the ethylene flowrate on catalytic activity of the compound catalyst and morphology of the as-grown MWCNTs was also investigated in this study. The dispersed active phases of the catalyst and optimized gas flowrate helped in improving the tube morphology and prevented the aggregation of the as-grown MWCNTs. The flowrates, below 100 sccm, did not provide sufficient reactants to interact with the catalyst for production of defectfree CNT structures. Above 100 sccm, concentration of the carbon precursor did not show notable influence on decomposition rate of the gas molecules. The most promising results on growth and structural properties of MWCNTs were gained at ethylene flowrate of 100 sccm. At this flowrate, the ratio of and intensity peaks ( / ) was deliberated about 1.40, which indicates the growth of graphitic structures of MWCNTs.

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Fluidized bed synthesis of carbon nanotubes – A review

Cited by 124 publications

References 202 publications

Decoration of Carbon Nanotubes by Semiconducting or Metallic Nanoparticles using Fluidized Bed Chemical Vapour Deposition

Decoration of Carbon Nanotubes by Semiconducting or Metallic Nanoparticles using Fluidized Bed Chemical Vapour Deposition

On thermodynamic equilibrium of carbon deposition from gaseous C-H-O mixtures: updating for nanotubes

Effect of Gas Flowrate on Nucleation Mechanism of MWCNTs for a Compound Catalyst

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