Carbon films produced from ionic liquid carbon precursors

1. A method for producing a film of porous carbon, the method comprising carbonizing a film of an ionic liquid, wherein said ionic liquid has the general formula (X +a ) x (Y −b ) y , wherein the variables a and b are, independently, non-zero integers, and the subscript variables x and y are, independently, non-zero integers, such that a·x=b·y, and at least one of X + and Y + possesses at least one carbon-nitrogen unsaturated bond.

2. The method according to claim 1 , wherein said carbon-nitrogen unsaturated bond is provided by a nitrile group.

3. The method according to claim 2 , wherein the X + portion of said ionic liquid includes a group with a positively charged nitrogen atom.

4. The method according to claim 3 , wherein said group with a positively charged nitrogen atom is a nitrogen-containing ring.

5. The method according to claim 4 , wherein said nitrogen-containing ring is an imidazolium ring.

6. The method according to claim 5 , wherein the ionic liquid has the structural formula:

wherein R 1 and R 2 are independently selected from hydrogen atom and hydrocarbon groups, wherein said hydrocarbon group is optionally substituted with one or more heteroatoms and/or heteroatom groups, and Y − is a counteranion.

7. The method according to claim 6 , wherein R 1 and R 2 are independently selected from hydrogen atom, hydrocarbon group, and nitrile-containing hydrocarbon group, provided that at least one of R 1 and R 2 is a nitrile-containing hydrocarbon group.

8. The method according to claim 7 , wherein said nitrile-containing hydrocarbon group has the formula:

—(CH 2 ) n —CN  (3)

wherein n is an integer of at least 1.

9. The method according to claim 7 , wherein Y − contains at least one carbon-nitrogen unsaturated bond.

10. The method according to claim 4 , wherein said nitrogen-containing ring is a pyrrolidinium ring.

11. The method according to claim 10 , wherein the ionic liquid has the structural formula:

wherein R 3 and R 4 are independently selected from hydrogen atom, hydrocarbon group, and nitrile-containing hydrocarbon group, and Y − is a counteranion, provided that at least one of R 3 and R 4 is a nitrile-containing hydrocarbon group when Y − does not contain a carbon-nitrogen unsaturated bond, and provided that Y − contains at least one carbon-nitrogen unsaturated bond when both R 3 and R 4 are not nitrile-containing hydrocarbon groups.

12. The method according to claim 11 , wherein R 3 and R 4 are independently selected from hydrogen atom, hydrocarbon group, and nitrile-containing hydrocarbon group, provided that at least one of R 3 and R 4 is a nitrile-containing hydrocarbon group, wherein Y − may or may not contain a carbon-nitrogen unsaturated bond.

13. The method according to claim 12 , wherein said nitrile-containing hydrocarbon group has the formula:

—(CH 2 ) n —CN  (3)

wherein n is an integer of at least 1.

14. The method according to claim 3 , wherein said group with a positively charged nitrogen atom is an acyclic ammonium group.

15. The method according to claim 14 , wherein the ionic liquid has the structural formula:

[NR 5 R 6 R 7 R 8 ] + [Y − ]  (5)

wherein R 5 , R 6 , R 7 , and R 8 are independently selected from hydrogen atom, hydrocarbon group, and nitrile-containing hydrocarbon group, and Y − is a counteranion, provided that at least one of R 5 , R 6 , R 7 , and R 8 is a nitrile-containing hydrocarbon group when Y − does not contain a carbon-nitrogen unsaturated bond, and provided that Y − contains at least one carbon-nitrogen unsaturated bond when none of R 5 , R 6 , R 7 , and R 8 are nitrile-containing hydrocarbon groups.

16. The method according to claim 15 , wherein R 5 , R 6 , R 7 , and R 8 are independently selected from hydrogen atom, hydrocarbon group, and nitrile-containing hydrocarbon group, provided that at least one of R 5 , R 6 , R 7 , and R 8 is a nitrile-containing hydrocarbon group, wherein Y − may or may not contain a carbon-nitrogen unsaturated bond.

17. The method according to claim 16 , wherein said nitrile-containing hydrocarbon group has the formula:

—(CH 2 ) n —CN  (3)

wherein n is an integer of at least 1.

18. The method according to claim 1 , wherein said carbon-nitrogen unsaturated bond is provided by an imino-containing group.

19. The method according to claim 18 , wherein said imino-containing group is in the X + portion of the ionic liquid.

20. The method according to claim 19 , wherein the X + portion of the ionic liquid includes an imino-containing ring.

21. The method according to claim 20 , wherein the ionic liquid has the structural formula:

wherein R 9 is a hydrogen atom, hydrocarbon group, or nitrile-containing hydrocarbon group, and Y − is a counteranion.

22. The method according to claim 1 , wherein Y − has the formula:

wherein m and n are independently 0 or an integer of 1 or above, and p is 0 or 1, provided that when p is 0, the group —N—SO 2 —(CF 2 ) n CF 3 subtended by p is replaced with an oxide atom connected to the sulfur atom, and when p is 1, the shown perfluoroalkyl groups can optionally crosslink to form a cyclic anion.

23. The method according to claim 22 , wherein Y − has the formula:

wherein in and n are independently 0 or an integer of 1 or above.

24. The method according to claim 22 , wherein Y − has the formula:

wherein in is 0 or an integer of at least 1.

25. The method according to claim 1 , wherein Y − contains at least one carbon-nitrogen unsaturated bond.

26. The method according to claim 25 , wherein Y − contains at least one nitrile group.

27. The method according to claim 26 , wherein Y − is selected from dicyanamide and tricyanamide anion.

28. The method according to claim 1 , wherein said method further includes, before said carbonization step, depositing said ionic liquid onto a substrate.

29. The method according to claim 28 , wherein said ionic liquid is deposited as a liquid without admixing said ionic liquid with a solvent.