One‐step separation of high‐purity (6,5) carbon nanotubes by multicolumn gel chromatography

We investigated the separation of the (6,5) chirality from a commercially available (6,5)‐enriched CoMoCAT single‐wall carbon nanotubes (SWCNTs) by the multicolumn gel chromatography method. Results show that several (6,5) fractions with different purities were sorted across the different gel columns. The metallic SWCNTs were collected as the finally unbound SWCNTs. The highest chirality purity of the (6,5) fractions after one‐step separation was 74.5%, which is much higher than that (∼53.8%) of the (6,5) fraction separated from HiPco SWCNTs which contain a broad chirality distribution. This result indicates that the multicolumn method can highly improve the separation yield and efficiency of a specific (n,m) species if it is present at a high level in the starting material.