Ribbon-Filled Composites

Diamonds have also been found by U.S. and German scientists. Greiner, Phillips, Johnson and Volk used the Franhofer Institute 1500 liter explosive chamber filled with argon to detonate explosive compositions of 40/60 TNT/RDX, 50/50 TNT/TATB, and 50/50 TNT/Nitroguanidine. The solid detonation products collected had two distinct powder forms. One form was compact spheroids of about 7 nanometer diameter identified as diamonds and the other form was curved ribbons of about 4 nanometers in thickness, identified as graphite. The structures were identified using convergent beam electron diffraction. The solid products collected were about 25% diamond. 

As is well known [40], compression of such composite stacks lamellae and amorphous layers along stiff lamellae gives rise to unstable kinking of the lamellae. This produces periodic undulations in the lamellae ribbons. The accentuated tensile stresses acting across the equatorial disks of a spherulite expand amorphous material within lamellae kinks into pores. Similar and complementary processes are expected to occur in polar fans of spherulites, however, no action is expected from the amorphous phase, but instead, from the lamellae ribbons. In this case, the chain fold planes in the lamellae form unstable stacks in tension. Any inhomogeneous lamellae kinks would be filled with amorphous material imder transverse pressure, producing no voids. Thus, the end result should be the array of aligned cavities in the equatorial disks of spherulites. 

---