Large-scale separation of metallic and semiconducting single-walled carbon nanotubes

A separation method involving a dispersion-centrifugation process in a tetrahydrofuran solution of amine, which makes metallic, single-walled nanotubes (SWNTs) highly concentrated to 87% in a simple way. The weakly absorbed amines are easily removable after separation and the separation method is simple and convenient, suggesting a potential industrial utilization for widespread applications of SWNTs.