STUDY OF THE STRUCTURE OF ULTRAFINE AND NANOMETRIC CARBONACEOUS PARTICULATE FORMED IN COMBUSTION

During my stay in Paris, I aim to extend the knowledge acquired in previous collaboration with CNRS by performing on soot samples an improved approach for HR TEM images analysis in order to obtain quantitative results about particulate organization at nanostructural level. Carbonaceous particulate, produced at IRC-CNR by using a controlled and reproducible combustion system burning in different experimental conditions will be analysed by HR-TEM. HRTEM will be performed on the collected soot samples using a JEOL 2011 electron microscope. Soot samples will be dispersed in methanol by ultrasonic agitation and dropped onto a carbon lacey grid. The number of the images to be acquired will be increased with respect to traditional microscopic analysis in order to be able applying a new mathematical morphologic analysis of images developed in collaboration with GEPEA-CNRS in Nantes. This new tool will be therefore tested for the first time on soot for obtaining structural information on the disordered portion of particles. A particular effort will be put on the evaluation of new key parameters like tortuosity and local curvature radii which account for the deviations from the planar shape of the graphene layers. Structural results from the new morphologic analysis will be matched with the information already gathered by off-line spectroscopic (IR to UV absorption and/or fluorescence, Raman spectroscopy) and chemical techniques (Mass spectrometry, Size Exclusion Chromatography, thermogravimetry, elemental analysis). All the results obtained from this multi-diagnostic approach will be matched in order to reconstruct the analytical puzzle of soot nano-scale organization.