Selective oxidation of single-walled carbon nanotubes using carbon dioxide

Smith, Milton R.; Hedges, Sheila W.; LaCount, R.B.; Kern, D.G.; Shah, Naresh; Huffman, G.P.; Bockrath, Bradley

doi:10.1016/s0008-6223(03)00054-x

“…Although highly purified and defect-free SWCNTs will oxidize at temperatures ≥ 700 ºC, it has been shown that the presence of even small quantities of impurity carbons can induce oxidation at lower temperatures [33]. Moreover, the position of T mr peak is also strongly affected by the amount and morphology of the metal impurities.…”

Section: Characterization Of the Swcnt Dispersionsmentioning

confidence: 99%

High performance PEEK/carbon nanotube composites compatibilized with polysulfones-I. Structure and thermal properties

Díez‐Pascual

¹

,

Naffakh

²

,

González‐Domínguez

³

et al. 2010

Carbon

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“…TEM images taken before and after the reaction with CO 2 show that in the case of the purified grade material the rope-like structures are left intact. 171 It is unexpected that a larger fraction of the purified sample would oxidize in the CO 2 treatment than for the raw material.…”

Section: Resultsmentioning

confidence: 99%

“…TEM images taken before and after the reaction with CO 2 show that in the case of the purified grade material the rope-like structures are left intact. 171 It is unexpected that a larger fraction of the purified sample would oxidize in the CO 2 treatment than for the raw material.This may be a result of the damage done to the nanotubes during the purification procedure. The data in hand do not permit an assignment of hydrogen adsorption capacity to particular fractions of carbon such as those identified by TGA for example.…”

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confidence: 99%

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University/NETL Student Partnership Program

Holder¹

2003

0

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Renewed interest in methane hydrates as a potential, unconventional energy source has prompted investigation into their thermal properties, which are necessary to determine heat flow through the hydrate for resource production.In this investigation thermal property measurements have been made on unconsolidated pure methane hydrate samples formed in a high-pressure variable-volume viewcell (HVVC). Using a transient plane source (TPS) technique, a single measurement was used tosimultaneously determine the thermal conductivity and thermal diffusivity of the methane hydrate inside the viewcell. A vessel was designed to contain the sample around the TPS for thermal property measurements while inside the HVVC. The vessel was successful in containing the sample during the hydrate formation experiments and its design made it possible to recover a methane hydrate sample, which was analyzed with Raman spectroscopy.The striking quality of methane hydrate is that its thermal conductivity is much lower than ice, despite its structural similarities to ice. The thermal conductivity of pure methane hydrate for a temperature range of 264 K to 277 K and pressure range of 11.6 MPa to 13.0 MPa, respectively, can be described by k = (-0.0034 T + 1.2324) W/mK, where T is in Kelvin. The average of the thermal conductivity values within this range of temperatures and pressures is k = 0.30 ± 0.02 W/mK. The sample was recovered and analyzed with Raman spectroscopy, confirming that the sample was pure hydrate.The thermal diffusivity of methane hydrate has only been reported by one other investigator in preliminary experiments. The thermal diffusivity of methane hydrates determined in the work reported herein for a temperature range of 264 K to 277 K and pressure range of 11.6MPa to 13.0 MPa, respectively, is α = (2.59 ± 0.16) × 10 -7 m 2 /s. The thermal diffusivity can also be described by α × 10 7 = (0.0005 T + 2.4424) m 2 /s where T is in Kelvin.iv Derivation ...................................................................................................................................116 Different τ -Values ...................................................... Dr. Gerald Holder, Dean of Engineering at the University of Pittsburgh, was my research advisor and though his role was remote, his support, knowledge, and advice was integral to my work. B.1.2 H(τ) Values From Numerical Integration at LIST OF TABLES LIST OF FIGURESI would like to thank Ronald Lynn of NETL. Ron played an integral role in upgrading and automating our experimental setup. He wrote the data acquisition program, automating data collection. He supplied his vast knowledge of National Instrument's software and hardware and was a great resource for learning LabVIEW.Dr. David Shaw of Geneva College developed most of the data analysis described here. He hired me as a research assistant while I was an undergraduate which led to an internship at NETL. As such, I was able to continue this work as a graduate student at Pitt. I thank him for his vast knowledge and w...

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“…CO 2 was found to be suitable for the selective removal of disordered carbon coming from the nanotube tips' destruction [166]. High temperature H 2 can be used to remove both amorphous carbon and carbon coating on metal catalyst particles [167], and NH 3 was used as a safer alternative to hydrogen [168].…”

Section: Purification Of Carbon Nanotubesmentioning

confidence: 99%

Carbon nanostructures with different dimensionality – From synthesis to applications

Puskás

¹

0

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Selective oxidation of single-walled carbon nanotubes using carbon dioxide

Cited by 78 publications

References 12 publications

High performance PEEK/carbon nanotube composites compatibilized with polysulfones-I. Structure and thermal properties

High performance PEEK/carbon nanotube composites compatibilized with polysulfones-I. Structure and thermal properties

University/NETL Student Partnership Program

Carbon nanostructures with different dimensionality – From synthesis to applications

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