The laser heating effect on the nanostructure of turbostratic carbon material as flame-formed soot

The present work reports about the laser-induced modifications undergone by a typical turbostratic carbon material as soot, formed at the first inception stage (nascent) and final maturation degree (mature) in different premixed flames. The structural modifications induced by laser heating were studied by advanced HRTEM imaging, provided the detailed characterization of the carbon network of pristine soot carried out by HRTEM, Raman, UV-Vis absorption and electron energy loss spectroscopy (EELS) [1,2]. The laser induced modifications resulted to be nanostructure-sensitive producing structures in form of "rosette" and void shells in the case of mature and coalesced amorphous material, respectively. These structures are observable in Fig. 1, where HRTEM images of nascent and mature ethylene soot before and after laser heating treatment are reported. The sensitivity to nanostructure is promising for developing laser heating as a structural diagnostic tool for carbon materials, but just such sensitivity has to be carefully considered when the laser is employed for diagnostic purposes.