De-agglomeration and homogenisation of nanoparticles in coal tar pitch-based carbon materials.

The aim of the work was to characterise coal tar pitch (CTP) modified with selected nanoparticles as a binder precursor for the manufacture of synthetic carbon materials. Different factors influencing the preliminary preparative steps in the preparation of homogenous nanoparticle/CTP composition were studied. Graphene flakes, carbon black and nano-sized silicon carbide were used to modify CTP. Prior to introducing them into liquid CTP, nanoparticles were subjected to sonication. Various dispersants were used to prepare the suspensions, i.e. water, ethanol, dimethylformamide (DMF) and N-methylpyrrolidone (NMP).The results showed that proper dispersant selection is one of the most important factors influencing the de-agglomeration process of nanoparticles. DMF and NMP were found to be effective dispersants for the preparation of homogenous nanoparticle-containing suspensions. The presence of SiC and carbon black nanoparticles in the liquid pitch during heat treatment up to 2000 °C leads to the inhibition of crystallite growth in carbon residue.