Chemical design of nanodiamond-carbon nanotube hierarchical nanostructures and their effect on mechanical properties of polyurea nanocomposites

A hierarchical carbon nanostructures (HCNs) that comprise various types of carbon nanoparticles with different structural dimensions attract increasing attention due to promise of performance enhancement of materials and devices through the structure promoted synergistic effects. HCNs, consisting of carbon nanofibers- nanotubes-metal nanoparticles , and graphene- carbon spheres , have been fabricated and their potential applications in advanced catalysts, fuel cells and supercapacitors for energy storage proposed. Hybrid carbon composite systems containing nanotube-diamond covalent interfaces have been considered theoretically and observed in experiments using high temperatures or gamma radiation. Synthesis of hybrid CNT-nanodiamond thin films by plasma CVD has also been reported. These studies are motivated by the design of such HCNs which integrate the strongest material (CNTs) with the hardest known (diamond) in expectation of wider range of properties than either CNTs or diamond that could enable applications in structural materials and nanoelectronics.