Abstract
Soot is characterized by a multiscale structural organization; the only diagnostic tool that can give access to it is the transmission electron microscope (TEM). However, as it is a diffraction-based technique, TEM images only conjugate aromatic systems and, thus, it is particularly useful to combine it with electron energy-loss spectroscopy (EELS), which is able to provide quantitative information about the relative abundance of sp3 and sp2 hybridized carbon. In this paper, a method for the EELS spectrum analysis of carbonaceous materials, recently developed for electron-irradiated graphite and glassy carbon composition analysis, has been applied for the first time on soot samples, in order to test its performance in soot nanostructure study in combination with TEM and high-resolution TEM (HRTEM). Soot samples analyzed were collected in the soot inception region of premixed flames of different hydrocarbon fuels. EELS, in agreement with TEM and HRTEM, showed a quite disordered and heterogeneous structure for young soot, with a relatively low sp2 content and slight presence of fullerene-like structures, more evident in the case of methane soot hinting to the effect of more saturated aliphatic fuels on soot characteristics at soot inception.
Highlights
Soot research is important given the effect of soot emission on climate change and environmental issues
These layers are parallel to each other with interplanar distances higher with respect to that of graphite, featuring a structure at the atomic scale corresponding to a turbostratic, i.e., biperiodic, stacking of a few nanometer-sized layers [1]. Due to this characteristic multi-scale organization, soot can be clearly distinguished from other carbon solid particles when observed by transmission electron microscopy (TEM)
TEM, is the only diagnostic tool giving access to the soot multi-scale organization and especially nanostructure, which can be explored by the high resolution mode of TEM (HRTEM), measuring structural parameters through mathematical approaches for image analysis [1]
Summary
Energy-Loss Spectroscopy for Keywords: soot; TEM; HRTEM; EELS; soot nanostructure; premixed flames. Investigating Nanostructure of Soot from Different Fuels. Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
