Design of multifunctional adhesives by the use of carbon nanoparticles

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.