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We investigated the influence of carbon materials on the properties of adhesives. With the aim of the development of conductive and mechanically improved adhesives, different types of multi-walled carbon nanotubes (MWNT), single-layer graphene, graphene nanoplatelets, graphite, and carbon black were dispersed into an epoxy adhesive. For inserting particles within the viscous matrices and to obtain homogenous and stable dispersions, two different methods namely a three-roll mill and a dual asymmetric centrifuge have been compared The results demonstrate that filling epoxies with carbon nanoparticles improves the conductivity differently. Measuring the electrical resistivity of MWNT-filled composites resulted in an electrical percolation starting underneath 0.1 wt.%. Further, with increasing the MWNT content, conductivity sharply increases. In contrast to the MWNT composites, other carbon nanoparticles require a higher filling content to reach similar values. With a filling ratio up to 17.0 wt.% for ACS graphene nanoplatelets 2–10 nm and the filling of 3.0 wt.% with MWNTs from Nanocyl, the lowest volume resistivities have been reached. [ABSTRACT FROM PUBLISHER]

Hollow graphitic carbon nanoparticles (HGCNs) obtained by catalytic graphitization of acetylene carbon black (ACB) were investigated using ultra-soft X-ray emission spectroscopy. The electronic structures of the ACB HGCNs were compared with those of HGCNs obtained from iron carbide-filled carbon nanocapsules (Fe3C@CNCs) and Q-graphenes. The occupation of the π sub-band decreased in the following sequence: Fe3C@CNC HGCNs > ACB HGCNs > Q-graphenes. This sequence can be explained by changes in the occupations of the C2p states due to the formation of bonds between carbon and residual metal atoms within the HGCNs. It was also found that the contribution of the overlapping ofppπ+ppσ-states in the ACB HGCN walls toward the spectra of the HGNCs was greater in comparison with the reference Q-graphenes. It was established that ACB was not fully transformed into the HGCNs. Scanning and transmission electron microscopy methods were used to study the spatial structures and morphologies of the fabricated HGCNs. [ABSTRACT FROM PUBLISHER]