Structure and Strength of Carbon Nanohorns

Research into Carbon Nano Horns or Cones (CNCs) started almost at the same time as the discovery of CNTs in 1991. The official report of the discovery of isolated Nano Cones was made in 1993, when Ge and Sattler from the University of Hawaii reported their observations of Carbon Cones mixed together with tubules on a flat graphite surface. The products were generated by quenching hot carbon vapor on th e substrate. Ge and Sattler also predicted that five apex angles, 19.2°, 38.9°, 60°, 86.6°, and 123.6°, could be used to distinguish CNCs. However, only the angle of 19.2° was found in the opening angles of their samples. The observed cones were up to 24 nm in length and 8 nm in base diameter. At that time, most of researchers focused on the investigation of CNTs, and the exploration of horns attracted little attention. Present paper converse about the structure and elastic moduli of these less explored nanostructures. The second-generation reactive bond order potential by Brenner and coworkers has been used to model these structures. CNT is a special case of Carbon Cone with zero apex angle. Young's Modulus and Shear Modulus are found to depend on the apex angle.