Raman spectroscopy of mini-CAST soot with various fractions of organic compounds: Structural characterization during heating treatment from 25 °C to 1000 °C

Research output: Contribution to journalArticle

Abstract

Soot particles undergo considerable changes in composition, morphology, as well as in internal structure during formation from the incipient particles to more mature aggregates, and still there is a lack of understanding of these mechanisms. In this study, soot produced by a mini-CAST soot generator was probed using Raman spectroscopy with focus on soot with large variation in size and fraction of organic compounds. The volatility of organic compounds and changes in internal bonding structures of the soot was surveyed by heating the samples from room temperature up to 1000 °C in a flow of inert N2 gas. The soot rich in organics showed more complex Raman spectra and stronger photoluminescence background. In particular, Raman signatures interpreted as the CH “out-of-plane” mode, ethers COC, and carbonyl CO groups were observed. During the heating treatment, these signatures disappeared, which was related to vaporization of the organics. Moreover, an enhancement of Raman band intensity of mature soot during heating treatment was observed for the first time. Our study thus brings new information on structural and compositional changes for soot during heating treatment in an inert atmosphere.

Details

Authors
Organisations
External organisations
  • LTH, Lund University
  • University of Paris-Sud
  • Ton Duc Thang University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Other Physics Topics
  • Physical Chemistry
  • Atom and Molecular Physics and Optics

Keywords

  • Raman spectroscopy, Soot, Organic compounds, ,Thermal treatment
Original languageEnglish
Pages (from-to)291-302
Number of pages11
JournalCombustion and Flame
Volume209
Publication statusPublished - 2019 Nov
Publication categoryResearch
Peer-reviewedYes