Continuous Separation of Metallic and Semiconducting Carbon Nanotubes Using Agarose Gel

Abstract

We have developed a novel method to separate metallic and semiconducting single-wall carbon nanotubes (SWCNTs) with high purities using agarose gel. When an SWCNTs/sodium dodecyl sulfate (SDS) dispersion was applied to a column containing agarose gel beads, semiconducting SWCNTs were trapped by the beads, while metallic SWCNTs passed through the column. After the semiconducting SWCNTs adsorbed to the beads were eluted with sodium deoxycholate solution, the column could be used for repeated separation. Because this continuous, repeatable separation method is applicable to a low-cost, large-scale process, it should enable the industrial production of metallic and semiconducting SWCNTs.

From metal/semiconductor separation to single‐chirality separation of single‐wall carbon nanotubes using gel

“…4c). The purities of the M-and S-SWCNTs were improved to 90% and 95% in comparison to those that were separated by electrophoresis and freeze, thaw, and squeeze methods, respectively [15][16][17]. The improvement of the purity can be explained by the difference of the region where the separation occurs.…”

“…To develop a more convenient process, a column chromatography method was applied to the separation (Fig. 4a) [17]. When the SWCNT/SDS dispersion followed by SDS solution was applied to the column that was filled with agarose gel beads (Sepharose, GE Healthcare), only the S-SWCNTs were adsorbed by the beads, whereas the M-SWCNTs were eluted through the beads (Fig.…”

“…Recently, novel M/S separation methods have been developed using agarose gel [15][16][17][18][19][20]. Agarose is a biopolymer obtained from algae and is a gel-forming linear polysaccharide with a 1,3-β-D-galactose and 1,4-α-L-3,6-anhydro-galactose repeat unit.…”

“…Thus, agarose gel electrophoresis was first applied to separate SWCNTs, and the M/S separation was successful [15]. In addition, the electric field was determined not to be required for the separation [16], and the continuous column method was developed [17]. Most recently, the single-chirality separation of SWCNTs using a multicolumn with a polysaccharide gel, cross-linked dextran, was reported [21].…”

Carbon nanotubes for ultrafast fibre lasers

“…Aside from that, the protein and DNA binding to CNT is very fruitful for medicine, as CNTs can deliver the medical drug, peptides, nucleic acids, crossing cell membranes [147]. Methods based on such interactions referred to as chromatography, include anion exchange chromatography (AEC) [146], size-exclusion chromatography [148] and electrokinetic chromatography [149]. DNA-coated CNT solutions benefit from high stability in the time domain; they stay stable for months at room temperature [150].…”