Carbon Nanotube Column
Carbon Nanotube Sorting and Purifying by Ion Exchange Chromatography
Wrapping of carbon tubes by synthetic single-stranded DNA was found that electrostatics of the DNA-CNT hybrid depends on tube diameter and electronic properties, enabling nanotube separation by anion exchange chromatography. Optical absorption and Raman spectroscopy show that early fractions are enriched in the small diameter and metallic tubes, where late fractions are enriched in the large diameter and semiconducting tubes. The purification of semiconducting single- walled carbon nanotubes (SWCNT) with a purity of 99% or higher is important in the electronic industry. The purification of semiconducting SWCNT from metallic SWCNT are related to hydrophilic and ligand density of anion exchange packing materials, column dimension and DNA-CNT hybrid.
The following are the comparison of conventional NS 1500 column to CNT-NS1500 column in the separation of single stranded synthetic oligonucleotides standard mixture. Hydrocell CNT-NS 1500 showed the longer and wider retention time in the separation of the same standard sample of 12-18 mer of phsophated oligothymidylic acid in the comparison with conventional NS 1500 for oligonucleotides and DNA fragment purification. The relationship of DNA-CNT hybrid and the characteristic of anion exchange packing materials in the purifu semiconducting single-walled carbon nanotubes are under investigation.