Fundamental aspects of nano-reinforced composites

The present paper highlights the potential of the CNTs as nanofillers in polymers, but also stresses out the limitations and challenges one has to face dealing with nanoparticles in general. The relation between particle size, separation and volume content is described analytically. The dominating effect of manufacturing route (sonication, mech. stirring and calendering) and surface properties of carbon nanotubes (CNTs), influencing the resulting degree of dispersion and interfacial adhesion, were intensively investigated by transmission electron microscopy (TEM). The resulting (fracture) mechanical properties of the CNT/epoxy composites were investigated for volume contents below 1%. The fracture toughness KIc turned out to be significantly increased (45%) adding only 0.3% of amino-functionalised double-walled carbon nanotubes (DWCNT-NH2).