Direct measurement of bending stiffness and estimation of Young's modulus of vertically aligned carbon nanofibers

Abstract

The bending stiffness of individual, as-grown, vertically aligned carbon nanofibers was measured using a custom-built atomic force microscope placed inside a scanning electron microscope. The internal structure of the nanofiber was best modeled as dual-phase, composed of an inner graphitic core covered with a tapered amorphous carbon shell. It was found that the fibers have a relatively low bending stiffness, with Young's modulus values of about 10 GPa for the inner core and 65 GPa for the outer shell. The low Young's modulus of the inner core is attributed to a non-zero angle between the graphitic sheets and the nanofiber axis. The weak shear modulus between graphitic sheets thereby dominates the mechanical behaviour of the fibers. V

A Reactive Molecular Dynamics Simulation Study of the Mechanical Response of Amorphous Sulfur–Graphitic Carbon Composite Cathodes

“…We note that the CNFs may consist of a thin turbostratic outer shell and graphitic inner part. 15,16 Furthermore, significant differences in bending stiffness (65 GPa for the outer shell and 10 GPa for the inner shell) of the respective parts have been measured for vertically aligned CNFs, 15 the smallest value being attributed to the low shear stiffness of graphite and its alignment with respect to the fiber axis. Consequently, a transfer of predominantly shear loads at the inner CNF-Li X S interface is expected.…”

Catalytic water cleaning: materials and transport aspects

“…Figure 1.6 clearly shows that CNF based supports have an inverse structure of a conventional porous support material providing an open structure which is advantageous in terms of porosity and tortuosity. In addition CNFs posses excellent mechanical stability (high young's modulus) [92] and chemically inertness [93].…”