Nanomechanics of carbon nanofibers: Structural and elastic properties

A general analytic expression for the Young’s modulus of a range of carbon nanofibers (CNFs) with single or multishell nanocone or cone stacked structures has been developed from continuum elastic theory. The Young’s modulus of a single-shell nanocone is found to be cos4θ of that of an equivalent single-wall carbon nanotube (CNT). The CNFs of short lengths and small tilting angles have very large Young’s modulus comparable to that of single or multiwall CNTs, whereas the inverse is true for the CNFs with long lengths and large tilting angles. The dependence of the stiffness of CNFs on various structural parameters has been predicted by the model, validated through full-scale molecular dynamics simulations, and categorized for scanning probe tip or reinforcing fiber type applications.