METHOD, ARRANGEMENT AND USE OF AN ARRANGEMENT FOR SEPARATING METALLIC CARBON NANOTUBES FROM SEMI-CONDUCTING CARBON NANOTUBES

• US 20060266675A1
• Filed: 04/02/2004
• Published: 11/30/2006
• Est. Priority Date: 04/08/2003
• Status: Active Grant

• Current Assignee: Forschungszentrum Karlsruhe Gmbh
• Original Assignee: Forschungszentrum Karlsruhe Gmbh
• Inventors: Hennrich, Frank, Krupke, Ralph
• Granted Patent: US 7,161,107 B2
• Time in Patent Office: Days
• US Class Current: 209/127.100
• CPC Class Codes: B03C 5/005 Dielectrophoresis, i.e. dielectric particles migrating towards the region of highest field strength B03C5/02 takes precedence; electrophoresis B01D57/02
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C01B 2202/22 Electronic properties
• CPC Class Codes: C01B 32/172 Sorting

Abstract

A method for separating metallic carbon nanotubes and semi-conducting carbon nanotubes includes providing a suspension containing a plurality of individual metallic carbon nanotubes and semi-conducting carbon nanotubes in a liquid, for which the dielectric constant ε_L meets the requirement: ε_M>ε_L>ε_H, wherein ε_M is the dieletric constant of the metallic carbon nanotubes and ε_H is the dielectric constant of the semi-conducting carbon nanotubes. A a non-homogeneous electric alternating field is applied to the suspension to create spatially separate species of the metallic carbon nanotubes and the semi-conducting carbon nanotubes. At least one of the separate species is then removed.

Claims

1. A method for separating metallic carbon nanotubes and semi-conducting carbon nanotubes, comprising:

providing a suspension containing a plurality of individual metallic carbon nanotubes and semi-conducting carbon nanotubes in a liquid, for which the dielectric constant ε

_L meets the requirement;

ε

_M>

ε

_L>

ε

_H,

wherein ε

_M is the dielectric constant of the metallic carbon nanotubes and ε

_H is the dielectric constant of the semi-conducting carbon nanotubes;

applying a non-homogeneous electric alternating field to the suspension to create spatially separate species of the metallic carbon nanotubes and the semi-conducting carbon nanotubes; and

removing at least one of the separate species.

2. The method according to claim 1, wherein the providing step includes forming a suspension in water of the carbon nanotubes.

3. The method according to claim 2, including adding a surfactant to the suspension as a separating mechanism.

4. The method according to claim 1, wherein the applying step includes using an alternating field having a peak-to-peak field intensity selected from a range between about 10³ V/m and about 10⁹ V/m.

5. The method according to claim 4, wherein the range is about 10⁴ V/m to about 10⁶ V/m.

6. The method according to claim 4, wherein the peak-to-to field intensity is about 10⁵ V/m.

7. The method according to claim 1, wherein the applying step includes using an alternating field having a frequency from a range between about 10 kHz and about 100 GHz.

8. The method according to claim 7, wherein the range is about 1 MHz to about 100 MHz.

9. The method according to claim 7, wherein the frequency is about 10 MHz.

10. (canceled)

11. (canceled)

12. (canceled)

13. (canceled)