ABSTRACT
Nanomechanical mapping of individual multi-walled carbon nanotubes (MWNT) has been undertaken to investigate intra-tube mechanical variations. Ultrasonic force microscopy has been used to measure the relative axial and radial variations of contact stiffness of MWNTs synthesized using chemical vapour deposition (CVD) and arc-discharge techniques. For CVD-based MWNTs the contact stiffness of the tube varied strongly across volume defects and is assumed to result from high crystalline defect densities associated with such radial variations. Although molecular dynamics simulations can provide insight into the effects of defects on MWNT effective modulus, all available experimental data treat MWNTs as idealized continuum beams or shells to model the effective modulus. The chapter presents ultrasonic force microscopy imaging data of the relative axial and radial variations of contact stiffness of individual MWNTs synthesized using CVD and arc discharge (AD) techniques. MWNTs were grown by conventional AD synthesis using an undoped graphitic anode/cathode pair.
