Separation of single wall carbon nanotubes
A method has been developed for the post-synthesis separation of nanotubes by size and/or type. Solubilized, functionalized nanotubes are passed over a GPC column such that length-separated fractions are collected. These length-separated fractions can then further be separated by diameter or type. Particularly useful are methods for separating nanotubes into metallic and semiconducting fractions.
1. A method of separating M-SWNTs and S-SWNTS comprising:
solubilizing the nanotubes, wherein the solubilizing comprises noncovalent functionalization of the nanotubes;
applying the solubilized nanotubes to a gel permeation chromatography column;
eluting the nanotubes;
collecting a first number of elution fractions, wherein the first number of fractions collected is sufficient to separate the nanotubes according to size;
selecting one or more of the collected fractions;
applying the selected fractions to a second gel permeation chromatography column;
eluting the nanotubes; and
collecting a second number of elution fractions, wherein the second elution is performed under a magnetic field sufficient to separate M-SWNTs and S-SWNTs.
2. The method of claim 1 further comprising separating the M-SWNTs or S-SWNTs by diameter.
3. The method of claim 2 wherein separating is by electrophoresis.
4. The method of claim 2 wherein separating is by chromatography over a nanoporous stationary support.
5. The method of claim 1 further comprising separating the M-SWNTS or S-SWNTs by chirality.
6. The method of claim 5 wherein separating is by chromatography through a column capable of separating compounds by chirality.
7. The method of claim 5 wherein separating is by preferential precipitation.
8. The method of claim 7 wherein preferential precipitation is on epitaxial crystalline surfaces.
9. A method of separating nanotubes according to diameter, comprising:
solubilizing the nanotubes, wherein the solubilizing comprises noncovalent functionalization of the nanotubes;
applying the nanotubes to a gel permeation chromatography column;
eluting the nanotubes;
collecting a first number of elution fractions, wherein the first number of fractions collected is sufficient to separate the nanotubes according to length;
selecting one or more of the elution fractions; and
subjecting the fractions to a second separation by diameter.
10. The method of claim 9 wherein the second separation is by electrophoresis.
11. The method of claim 9 wherein the second separation is by chromatography on a nanoporous stationary phase.