DISCUSSION ON THE MECHANICAL-BEHAVIOR OF CARBON NANOTUBE C60 COMPOSITE BASED ON OBSERVATION OF INTERFACIAL STRUCTURE/

The effects of the interfacial fine structure (interfacial bonding int eraction) on the mechanical properties of nanotube/C60 composite were examined by high resolution transmission electron microscope (HRTEM) o bservations of nanotube/vapor-deposited C60 crystal interfaces and pul l-out tests of high modulus carbon fiber with a vapor-deposited C60 si ngle crystal. Interfaces between nanotube and {111}-faceted C60 crysta l were observed to possess a parallel orientation relationship between the tube axis and [110] of the C60 crystal. The shear strength of the carbon fiber/C60 composite was estimated to be 4.4 x 10(-2) MPa. Inte rfacial sliding was observed in the carbon fiber/C60 single crystal in terface without deformation of the C60 matrix nor the fracture of fibe r. It has been inferred that the pull-out of the carbon fiber from the C60 matrix is due to the shear sliding, which is caused by the weak b onding between graphitic basal plane and C60. The experiments have ind icated that the ductility of the nanotube/C60 composite originates pro bably from sliding at the interface between the nanotube and the C60 m atrix.