HRTEM and EELS investigations of flame-formed soot nanostructure

B. Apicella, A. Ciajolo, A. Tregrossi, J. Abrahamson, Randy Lee Vander Wal, C. Russo

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

High resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) were applied to soot probed along a premixed methane flame from the inception phase up to the burnout region in order to follow the transformations of soot nanostructures. The nascent methane soot presented the predominance of large coalesced disordered structures in comparison to young, intermediate and mature soot presenting spherule aggregates. Quantitative structural information describing the shape, size and orientation of sp2-bonded (aromatic) layers and their distribution inside the carbon particle were obtained by HRTEM image analysis. A moderate structural improvement in terms of a better stacking of longer and more planar layers along with the tortuosity fringe decrease was observed along the methane flame. EELS was instead used to provide quantitative information about the relative concentrations of sp3 and sp2 hybridized carbon. It is the first time that quantitative EELS is applied to soot from the inception to maturation along a premixed laminar flame. The aromatic content for the nascent soot resulted to be rather high (84%) indicating the predominant aromatic character of soot precursors. The steep increase of sp2 content from 84 to 94% in the passage from nascent to young soot was noteworthy. The similar sp2 content (94–96%) as well as the invariance of fringe length of young, intermediate and mature soot testified that most of the structural changes occurred at the inception, after then methane soot did not undergo a significant nanostructural restructuring, possibly because of the less reactive environment generated from methane combustion.

Original languageEnglish (US)
Pages (from-to)218-224
Number of pages7
JournalFuel
Volume225
DOIs
StatePublished - Aug 1 2018

Fingerprint

Soot
Electron energy loss spectroscopy
High resolution transmission electron microscopy
Nanostructures
Methane
Carbon
Invariance
Image analysis

All Science Journal Classification (ASJC) codes

  • Chemical Engineering(all)
  • Fuel Technology
  • Energy Engineering and Power Technology
  • Organic Chemistry

Cite this

Apicella, B., Ciajolo, A., Tregrossi, A., Abrahamson, J., Vander Wal, R. L., & Russo, C. (2018). HRTEM and EELS investigations of flame-formed soot nanostructure. Fuel, 225, 218-224. https://doi.org/10.1016/j.fuel.2018.03.091
Apicella, B. ; Ciajolo, A. ; Tregrossi, A. ; Abrahamson, J. ; Vander Wal, Randy Lee ; Russo, C. / HRTEM and EELS investigations of flame-formed soot nanostructure. In: Fuel. 2018 ; Vol. 225. pp. 218-224.
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abstract = "High resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) were applied to soot probed along a premixed methane flame from the inception phase up to the burnout region in order to follow the transformations of soot nanostructures. The nascent methane soot presented the predominance of large coalesced disordered structures in comparison to young, intermediate and mature soot presenting spherule aggregates. Quantitative structural information describing the shape, size and orientation of sp2-bonded (aromatic) layers and their distribution inside the carbon particle were obtained by HRTEM image analysis. A moderate structural improvement in terms of a better stacking of longer and more planar layers along with the tortuosity fringe decrease was observed along the methane flame. EELS was instead used to provide quantitative information about the relative concentrations of sp3 and sp2 hybridized carbon. It is the first time that quantitative EELS is applied to soot from the inception to maturation along a premixed laminar flame. The aromatic content for the nascent soot resulted to be rather high (84{\%}) indicating the predominant aromatic character of soot precursors. The steep increase of sp2 content from 84 to 94{\%} in the passage from nascent to young soot was noteworthy. The similar sp2 content (94–96{\%}) as well as the invariance of fringe length of young, intermediate and mature soot testified that most of the structural changes occurred at the inception, after then methane soot did not undergo a significant nanostructural restructuring, possibly because of the less reactive environment generated from methane combustion.",
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Apicella, B, Ciajolo, A, Tregrossi, A, Abrahamson, J, Vander Wal, RL & Russo, C 2018, 'HRTEM and EELS investigations of flame-formed soot nanostructure', Fuel, vol. 225, pp. 218-224. https://doi.org/10.1016/j.fuel.2018.03.091

HRTEM and EELS investigations of flame-formed soot nanostructure. / Apicella, B.; Ciajolo, A.; Tregrossi, A.; Abrahamson, J.; Vander Wal, Randy Lee; Russo, C.

In: Fuel, Vol. 225, 01.08.2018, p. 218-224.

Research output: Contribution to journalArticle

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T1 - HRTEM and EELS investigations of flame-formed soot nanostructure

AU - Apicella, B.

AU - Ciajolo, A.

AU - Tregrossi, A.

AU - Abrahamson, J.

AU - Vander Wal, Randy Lee

AU - Russo, C.

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Y1 - 2018/8/1

N2 - High resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) were applied to soot probed along a premixed methane flame from the inception phase up to the burnout region in order to follow the transformations of soot nanostructures. The nascent methane soot presented the predominance of large coalesced disordered structures in comparison to young, intermediate and mature soot presenting spherule aggregates. Quantitative structural information describing the shape, size and orientation of sp2-bonded (aromatic) layers and their distribution inside the carbon particle were obtained by HRTEM image analysis. A moderate structural improvement in terms of a better stacking of longer and more planar layers along with the tortuosity fringe decrease was observed along the methane flame. EELS was instead used to provide quantitative information about the relative concentrations of sp3 and sp2 hybridized carbon. It is the first time that quantitative EELS is applied to soot from the inception to maturation along a premixed laminar flame. The aromatic content for the nascent soot resulted to be rather high (84%) indicating the predominant aromatic character of soot precursors. The steep increase of sp2 content from 84 to 94% in the passage from nascent to young soot was noteworthy. The similar sp2 content (94–96%) as well as the invariance of fringe length of young, intermediate and mature soot testified that most of the structural changes occurred at the inception, after then methane soot did not undergo a significant nanostructural restructuring, possibly because of the less reactive environment generated from methane combustion.

AB - High resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) were applied to soot probed along a premixed methane flame from the inception phase up to the burnout region in order to follow the transformations of soot nanostructures. The nascent methane soot presented the predominance of large coalesced disordered structures in comparison to young, intermediate and mature soot presenting spherule aggregates. Quantitative structural information describing the shape, size and orientation of sp2-bonded (aromatic) layers and their distribution inside the carbon particle were obtained by HRTEM image analysis. A moderate structural improvement in terms of a better stacking of longer and more planar layers along with the tortuosity fringe decrease was observed along the methane flame. EELS was instead used to provide quantitative information about the relative concentrations of sp3 and sp2 hybridized carbon. It is the first time that quantitative EELS is applied to soot from the inception to maturation along a premixed laminar flame. The aromatic content for the nascent soot resulted to be rather high (84%) indicating the predominant aromatic character of soot precursors. The steep increase of sp2 content from 84 to 94% in the passage from nascent to young soot was noteworthy. The similar sp2 content (94–96%) as well as the invariance of fringe length of young, intermediate and mature soot testified that most of the structural changes occurred at the inception, after then methane soot did not undergo a significant nanostructural restructuring, possibly because of the less reactive environment generated from methane combustion.

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Apicella B, Ciajolo A, Tregrossi A, Abrahamson J, Vander Wal RL, Russo C. HRTEM and EELS investigations of flame-formed soot nanostructure. Fuel. 2018 Aug 1;225:218-224. https://doi.org/10.1016/j.fuel.2018.03.091