Preparation of the layer-by-layer assembled materials from dispersions of highly anisotropic colloids

1. A method for the assembly of a thin film containing highly anisotropic colloids comprising the steps of:

a) immersing a substrate in a first solution or dispersion comprising a first substance, said first substance having an affinity for said substrate; and

b) immersing said substrate in a second solution or dispersion comprising a second substance, said second substance having an affinity for said first substance, to obtain at least a two layer thin film; and

wherein at least one of said first substance and said second substance is a highly anisotropic colloid wherein said colloid comprises rods or tubes having geometric dimensions of length, width and height wherein said length is greater than said width and said height by a ratio of at least 1:1.5.

2. The method of claim 1 wherein:

said affinities result from an electrostatic attraction between oppositely charged materials.

3. The method of claim 1 wherein:

said affinities result from van der Waals forces between said substances and said substrate.

4. The method of claim 1 wherein:

said affinities are due to a combination of electrostatic and van der Waals forces between said substances and said substrate.

5. The method of claim 1 wherein:

said first substance and said second substance are biological substances.

6. The method of claim 1 wherein:

said first substance and said second substance are structural stabilizing materials.

7. The method of claim 1 wherein:

said at least one of said first and said second substances is a highly anisotropic colloid comprising single wall carbon nanotubes that are soluble or dispersed in a polar solvent.

8. The method of claim 1 wherein:

said at least one of said first and said second substances is a highly anisotropic colloid comprising multi wall carbon nanotubes that are soluble or dispersed in a polar solvent.

9. The method of claim 1 wherein:

said at least one of said first and said second substances is a highly anisotropic colloid comprising oxide tubules that are soluble or dispersed in a polar solvent.

10. The method of claim 1 wherein:

said at least one of said first and said second substances is a highly anisotropic colloid comprising metal nanowires that are soluble or dispersed in a polar solvent.

11. The method of claim 1 wherein:

said at least one of said first and said second substances is a highly anisotropic colloid comprising semiconductor nanowires that are soluble or dispersed in a polar solvent.

12. The method of claim 1 wherein:

said at least one of said first and said second substances is a highly anisotropic colloid comprising metal nanorods that are soluble or dispersed in a polar solvent.

13. The method of claim 1 wherein:

said at least one of said first and said second substances is a highly anisotropic colloid comprising semiconductor nanorods that are soluble or dispersed in a polar solvent.

14. The method of claim 1 wherein:

said at least one of said first and said second substances is a highly anisotropic colloid comprising fibrous high aspect ratio polymers that are soluble or dispersed in a polar solvent.

15. The method of claim 1 wherein:

said at least one of said first and said second substances is a highly anisotropic colloid comprising J-aggregates from organic dyes that are soluble or dispersed in a polar solvent.

16. The method of claim 1 wherein:

a placement and orientation of said highly anisotropic colloid is controlled by patterns applied to said substrate and to interfaces between said patterns.

17. The method of claim 1 wherein:

an orientation of said highly anisotropic colloid is controlled by mechanical stress.

18. The method according to claim 1 wherein:

said first substance and said second substance are organic.

19. The method according to claim 1 wherein said ratio is a ratio between 1:10 and 1:100.

20. The method according to claim 1 wherein said ratio is a ratio greater than 1:100.

21. The method of claim 1 further comprising the step of:

rinsing said substrate with a solvent.

22. The method of claim 2 further comprising the step of:

drying said substrate.

23. The method of claim 21 further comprising the step of:

periodically replacing the solution or dispersion of said first substance with a solution or dispersion comprising of a third substance, said third substance having an affinity for said substrate.

24. The method of claim 1 further comprising the step of:

repeating steps (a) to (b) a predetermined number of times to create a multi-layer film.

25. The method of claim 24 further comprising the step of:

periodically replacing the second solution comprising dispersion of said second substance with a third solution or dispersion comprising a third substance, said third substance having an affinity for said first substance.

26. The method of claim 24 further comprising the step of:

further processing after the deposition of all layers by exposing the film to a solution of different pH.

27. The method of claim 24 further comprising the step of:

further processing after the deposition of all layers by exposing the film to a solution of a high salt concentration.

28. The method of claim 24 further comprising the step of:

further processing after the deposition of all layers by exposing the film to a high humidity environment.

29. The method of claim 24 further comprising the step of:

further processing after the deposition of all layers by exposing the film to a low humidity environment.

30. The method of claim 24 further comprising the step of:

further processing after the deposition of all layers by subjecting the film to mechanical stress after preparation to change physical and/or chemical properties of said film.

31. The method of claim 24 further comprising the step of:

preventing phase separation of said highly anisotropic colloid from polyelectrolytes used in other deposition layers.

32. The method of claim 1 wherein:

said steps of immersion comprise a deposition step; and

an orientation of said highly anisotropic colloid is controlled by a flow of liquid containing said highly anisotropic colloid past said substrate during said deposition step.

33. The method of claim 32 wherein:

said flow takes place in a flow cell that includes an open loop or a closed loop circulator.

34. The method of claim 32 wherein:

said flow is provided by an oriented spray aimed at a desired direction to a surface of said substrate.

35. The method of claim 1 wherein:

an orientation of said highly anisotropic colloid is controlled by a magnetic or electrical field.

36. The method of claim 35 wherein:

said highly anisotropic colloid is sensitive to said magnetic or electric field.

37. The method of claim 1 , further comprising the step of:

removing said thin film from the substrate after its preparation.

38. The method according to claim 37 further comprising the step of:

producing a material of desired dimensions by folding said thin film.

39. The method according to claim 38 wherein said step of producing further comprises:

combining multiple ones of said folded thin films.

40. The method according to claim 38 further comprising:

compacting said folded films to produce a bulk analog of said thin film.

41. The method according to claim 40 further comprising:

chemically treating said bulk analog to combine films.