Structure and porosity of conductive carbon blacks

Highlights: • SEM and HRTEM of two conductive carbon black grades. • Nitrogen adsoption, BET and NL-DFT for porosity features. • DSC Thermoprosimetry and NMR relaxometry. • Correlation of structural and porosity features to electric conductivity of carbon black polymeric nanocomposites. The structure and porosity of carbon black (CB) grades determine the ultimate applications of these most industrially used members of carbon materials. Hence, one uses complimentary methods to investigate these features for two conductive CB grades in order to understand their effects on the electric properties of polymeric nanocomposites. The mean particle size, the aggregate structure and voids morphology are studied by scanning electron microscopy (SEM) whereas high resolution transmission electron microscopy (HRTEM) reveals the ordering of the graphitic layers inside a CB particle as well as particles interconnections. The specific surface, voids size distribution and specific voids volume are studied using nitrogen adsorption, differential scanning calorimetry (DSC) thermoporosimety and nuclear magnetic resonance (NMR) relaxometry. This comparative study revealed a relatively smaller particle size, higher specific surface and specific volume with more disorder graphitic layers in Ketjenblack EC600JD than in Printex XE2. Finally, one presents the effect of such structural and porosity differences on the electric conductivity of nanocomposites made of these two grades.