Classification of Commercialized Carbon Nanotubes into Three General Categories as a Guide for Applications

We propose a general guideline for the application of commercialized carbon nanotubes (CNTs) by making correlations between the structures and properties for various single-walled, double-walled, and multiwalled CNTs. On the basis of these correlations, three general categories emerged: (1) low crystallinity and low specific surface area (SSA; large-diameter multiwalled CNTs); (2) low crystallinity and high SSA (large-diameter single- and double-walled CNTs); (3) high crystallinity and moderate SSA (small-diameter single-walled CNTs). This categorization would accelerate the industrialization of CNTs by easily identifying the suitable CNTs for a given application.