Solvent-based and water-based carbon nanotube inks with removable additives

1. An ink composition comprising:

a plurality of carbon nanotubes;

a solvent; and

a triazole-based removable additive that stabilizes the plurality of carbon nanotubes in the solvent,

wherein the triazole-based removable additive is a 1,2,4-triazole compound having a chemical formula:

wherein each of R 1 , R 2 , and R 3 is hydrogen.

2. The ink composition of claim 1 wherein the plurality of carbon nanotubes comprise one or more of: single-walled carbon nanotubes, metallic single-walled carbon nanotubes, semiconducting single-walled carbon nanotubes, and mixtures thereof.

3. The ink composition of claim 1 , wherein the plurality of carbon nanotubes are enriched in one of: metallic single-walled carbon nanotubes and semiconducting single-walled carbon nanotubes.

4. The ink composition of claim 1 , wherein the solvent is one of: water, N-methylpyrrolidinone (NMP), propylene glycol monomethyl ether acetate (PGMEA), methyl ethyl ketone (MEK), and methyl isopropyl ketone.

5. The ink composition of claim 1 , wherein the triazole-based removable additive is selected to act as a dispersal agent and a stabilization agent.

6. The ink composition of claim 1 , wherein the ink composition is in the form of a film deposited on a substrate and wherein a substantial portion of the triazole-based removable additive is removed from the film by thermal annealing.

7. The ink composition of claim 1 , wherein the additive is a non-ionic additive.

8. A method of preparing an ink composition according to claim 1 , the method comprising:

mixing the plurality of carbon nanotubes, the triazole-based removable additive, and the solvent, wherein the plurality of carbon nanotubes are dispersed within the solvent and wherein the triazole-based removable additive stabilizes the plurality of carbon nanotubes that are dispersed in the solvent.

9. The method of claim 8 , wherein the plurality of carbon nanotubes comprise one or more of: single-walled carbon nanotubes, metallic single-walled carbon nanotubes, semiconducting single-walled carbon nanotubes, and mixtures thereof.

10. The method of claim 8 , wherein the plurality of carbon nanotubes are enriched in one of: metallic single-walled carbon nanotubes and semiconducting single-walled carbon nanotubes.

11. The method of claim 8 , wherein the solvent is one of: water, N-methylpyrrolidinone (NMP), propylene glycol monomethyl ether acetate (PGMEA), methyl ethyl ketone (MEK), and methyl isopropyl ketone.

12. The method of claim 8 , further comprising providing the plurality of carbon nanotubes in the form of a wet paste to a solution that includes the triazole-based removable additive and the solvent.

13. The method of claim 8 , further comprising stabilizing the plurality of carbon nanotubes by providing the triazole-based removable additive to a solution that includes the plurality of carbon nanotubes and the solvent.

14. The method of claim 8 , further comprising:

stabilizing the plurality of carbon nanotubes by applying the triazole-based removable additive to the plurality of carbon nanotubes prior to dispersing the plurality of carbon nanotubes in the solvent; and

providing the solvent to the plurality of carbon nanotubes and the triazole-based removable additive.

15. The method of claim 8 , further comprising:

applying the ink composition to a substrate; and

removing a substantial portion of the triazole-based removable additive by thermal annealing, wherein the triazole-based removable additive is removed after applying the ink composition to a substrate.

16. The method of claim 8 , further comprising purifying the plurality of carbon nanotubes prior to adding the triazole-based removable additive and the water-based solvent.

17. The method of claim 16 , wherein the plurality of carbon nanotubes are purified by washing the plurality of carbon nanotubes in a solution of ammonium hydroxide.

18. The method of claim 8 , further comprising purifying a mixture including the plurality of carbon nanotubes, the triazole-based removable additive, and the water-based solvent by reducing impurities using centrifugation.

19. The method of claim 18 , wherein the centrifugation reduces amorphous carbon impurities.

20. The method of claim 18 , wherein a first portion of the centrifuged mixture is stored as the ink composition and a second portion of the centrifuged mixture is discarded.

21. The method of claim 18 , further comprising passing at least a portion of the centrifuged mixture through a filter to remove particle impurities having a diameter greater than a given size.

22. A method of preparing an ink composition according to claim 1 , the method comprising:

providing a paste that includes the plurality of carbon nanotubes which are single-walled carbon nanotubes;

purifying the paste that includes the plurality of single-walled carbon nanotubes in a solution of ammonium hydroxide to substantially reduce amorphous carbon impurities;

forming a mixture by adding the 1,2,4-triazole compound having the chemical formula:

wherein each of R 1 , R 2 , and R 3 is hydrogen,

and the solvent which is a water-based solvent to the purified paste that includes the plurality of single-walled carbon nanotubes, wherein the plurality of single-walled carbon nanotubes are dispersed within the water-based solvent and wherein the 1,2,4-triazole compound stabilizes the plurality of single-walled carbon nanotubes that are dispersed in the water-based solvent; and

purifying the mixture by centrifugation, wherein a first portion of the centrifuged mixture is stored as the ink composition according to claim 1 and a second portion of the centrifuged mixture is discarded.