Synthesis of carbon nanotube: nanodiamond hierarchical nanostructures and their polyurea nanocomposites

Hierarchical carbon nanostructures (HCNs) comprising functionalized nanodiamond par ticles (ND) covalently bonded to carbon nanotubes (CNTs) through urea or ethylene diamine linkers were synthesized using wet chemistry technique. Atomic force microscopy, transmis sion electron spectroscopy, and scanning electron spectroscopy reveal the pearlnecklacelike morphology of new HCNs with up to 50% of the CNT surface decorated by ND particles. Nanocomposites fabricated using polyuria/polyurethane hybrid polymer matrix and 0.2 wt.% of HCNs as a reinforcing filler show a 64% increase in tensile and elongation strength at break relatively to neat polymer.