ABSTRACT
The measured stress-strain curves from the tensile-loading experiments outlined in Fig. 9.1, for individual SWCNT ropes, are given in Fig. 9.2. Here, each rope diameter is measured at high magnification (~100,000) using a scanning electron microscope (SEM) to an accuracy of a few nanometers. The stress values have been calculated using the cross-sectional area of the perimeter SWCNT only, according to the geometric model given in Fig. 9.1f.Using the perimeter model, from 15 SWCNT ropes it was found that the breaking strength ranged from 13 to 52 GPa (with a mean value of 30 GPa) and the Young’s modulus values ranged from 320 to 1470 GPa (with a mean value of 1002 GPa). Moreover, there did not appear to be a dependence of breaking strength or Young’s modulus on the rope’s diameter.6
