“…Figure b illustrates the alternating-layer microstructures of aligned CNTs coming from the cross-section (bright circular shapes) and misaligned CNTs (long, gray lines) as well as relatively uniform sizes of the residual catalyst particles (black dots appearing from Z contrast). The misaligned CNT layers could also include amorphous carbon and other organic impurities formed during the manufacturing process. ,, Previous investigations in MIRALON CNT yarns as well as in other CNT yarns found collapsed CNTs formed dog-bone-like graphitic crystal molecular structures, which proved to be a critical contributor to their high strength. ,,, Figure b,c displays the unique CNT self-assembling phenomenon observed in the CNT yarns investigated in the study, similar to those investigations. Large diameter tubes with a smaller number of walls tend to collapse at diameters above 7.8 nm for double-walled CNTs (DWCNTs).…”