Figure 2. Classification of carbon nanotubes

From

Carbon Nanotube: A Review on Introduction, Fabrication Techniques and Optical Applications

Ekta Singh, Richa Srivastava, Utkarsh Kumar, Anamika. D. Katheria

Nanoscience and Nanotechnology Research. 2017, 4(4), 120-126 doi:10.12691/nnr-4-4-1