In this study, the influence of the addition of carbon nanotubes (CNTs) and carbon black (CB) on the graphitization temperature and microstructure of coal tar pitch (CTP) are investigated. X-ray diffraction patterns of carbon residues indicate that minimum interlayer spacing (d 002 ) values are obtained at 2000C for CTP/CNT. Moreover, the Raman spectrum of CTP/CNTs is similar to graphite, and the relative intensity of Raman lines shows that CTP/CB is less graphitized at 2000 C. In addition, scanning electron microscopy images show that when CB is added sample textures tend to disordered morphologies. However, CNTs, not only improve the morphology of CTP, but also act as nuclei for the growth of graphite flaky crystallites. The role of the CTP/CNT interface and the defects of CNTs on the graphitization degree are studied using transmission electron microscopy, and a mechanism for the graphitization of CTP, in the presence of CNTs, is proposed.

In this study, the rheological behavior of carbon black suspension with different amounts of three deflocculants (Dispex G40, Dispex N40 and CMC) has been investigated. As the rheological behavior of carbon black is markedly dependent on pH, the effect of the increase in pH has been studied. Dispex G40 and Sodium carboxymethycellulose (CMC), are effective in promoting complete deflocculation of carbon black suspensions with 20, 30 and 40 wt% solids concentrations for Dispex G40, and 40 wt% for CMC. 40 wt% suspensions containing Dispex N40 exhibit a yield stress at all levels of deflocculant investigated. However, a minimum in the extrapolated yield stress and apparent viscosity curve indicates that there is an optimum deflocculation level. The addition of alkali enhances the deflocculating power of CMC and Dispex G40, reducing any existing yield stress to zero. However, it would appear that Dispex N40 is desorbed when the pH is increased as rapid coagulation of the system is apparent, arising from a reduction in the repulsive forces.