Method of making carbon nanotube dispersions for the enhancement of the properties of fluids

• US 8,951,942 B2
• Filed: 06/19/2009
• Issued: 02/10/2015
• Est. Priority Date: 06/20/2008
• Status: Active Grant

• Current Assignee: Alan Hardwick Windle, Krzysztof Kazimiers Koziol, Martin Pick
• Original Assignee: Alan Hardwick Windle, Krzysztof Kazimiers Koziol, Martin Pick
• Inventors: Pick, Martin, Koziol, Krzysztof Kazimiers, Windle, Alan Hardwick
• Primary Examiner(s): VASISTH, VISHAL V
• Application Number:
  US13/000,289
• Publication Number:
  US 20110224113A1
• Time in Patent Office: 2,062 Days
• Field of Search: 508/116, 508/113, 508/131, 508/126, 508/130, 508/128, 977/742
• US Class Current: 508/116
• CPC Class Codes: C10M 113/02 Carbon; Graphite
• CPC Class Codes: C10M 125/02 Carbon; Graphite
• CPC Class Codes: C10M 171/06 Particles of special shape or size
• CPC Class Codes: C10M 177/00 Special methods of preparation of lubricating compositions; Chemical modification by after-treatment of components or of the whole of a lubricating composition, not covered by other classes
• CPC Class Codes: C10M 2201/02 Water
• CPC Class Codes: C10M 2201/041 Carbon; Graphite; Carbon black
• CPC Class Codes: C10M 2201/0416 used as thickening agents
• CPC Class Codes: C10M 2203/1006 used as base material
• CPC Class Codes: C10M 2205/0285 used as base material
• CPC Class Codes: C10M 2219/044 Sulfonic acids, Derivatives thereof, e.g. neutral salts
• CPC Class Codes: C10M 2229/025 used as base material
• CPC Class Codes: C10N 2010/02 Groups 1 or 11
• CPC Class Codes: C10N 2020/055 Particles related characteristics
• CPC Class Codes: C10N 2020/06 Particles of special shape or size
• CPC Class Codes: C10N 2020/061 Coated particles
• CPC Class Codes: C10N 2020/063 Fibrous forms
• CPC Class Codes: C10N 2030/02 Pour-point; Viscosity index
• CPC Class Codes: C10N 2030/06 Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• CPC Class Codes: C10N 2030/68 Shear stability
• CPC Class Codes: C10N 2040/04 Oil-bath; Gear-boxes; Automatic transmissions; Traction drives
• CPC Class Codes: C10N 2040/042 : for automatic transmissions
• CPC Class Codes: C10N 2040/044 : for manual transmissions
• CPC Class Codes: C10N 2040/046 : for traction drives
• CPC Class Codes: C10N 2040/08 : Hydraulic fluids, e.g. brake-fluids
• CPC Class Codes: C10N 2040/25 : Internal-combustion engines
• CPC Class Codes: C10N 2050/10 : Semi-solids; greasy
• CPC Class Codes: C10N 2060/00 : Chemical after-treatment of the constituents of the lubricating composition
• CPC Class Codes: C10N 2060/06 : by epoxydes or oxyalkylation reactions
• CPC Class Codes: C10N 2060/09 : Treatment with nitrogen containing compounds
• CPC Class Codes: C10N 2060/12 : by phosphorus or a compound containing phosphorus, e.g. PxSy
• CPC Class Codes: Y10S 977/742 : Carbon nanotubes, CNTs

Abstract

A method for the preparation of carbon nanotube modified fluids such, that the dispersion of nanotubes in such fluids, exampled by those which are oil based is enhanced through the combined use of mechanical, sonic and ultrasonic devices.

Claims

1. A method of dispersing nanostructures in a containing matrix comprising the steps of:

mixing a containing matrix including nanostructures;

applying a high shear mechanical mixing to the mixture;

applying an ultrasonic mixing to the mixture,

wherein the high shear mechanical mixing is applied synchronously with the ultrasonic mixing; and

,

producing an agglomerate free dispersion of nanostructures within the mixture.

2. The method of claim 1 wherein the nanostructures are carbon nanotubes.

3. The method of claim 1 wherein the nanostructures are nanofibers.

4. The method of claim 2 wherein a weight fraction of carbon nanotubes present in a liquid crystalline region is between 2 wt % to 30 wt % based on a total weight of a dispersion.

5. The method of claim 3 wherein a weight fraction of nanofibers present in a liquid crystalline region is between 2 wt % to 30 wt % based on a total weight of the dispersion.

6. The method of claim 2 wherein the weight fraction of carbon nanotubes present is an isotropic mix in a region of 0.001 wt % to 30 wt % of nanostructures based on the total weight of a dispersion.

7. The method of claim 3 wherein the weight fraction nanofibers present is an isotropic mix in a region of 0.001 wt % to 30 wt % of nanostructures based on the total weight of the dispersion.

8. The method of claim 2 wherein the carbon nanotubes are different types with heteroatomic doping.

9. The method of claim 3 wherein the nanofibers are different types with heteroatomic doping.

10. The method of claim 2 wherein the carbon nanotubes are surface modified.

11. The method of claim 3 wherein the nanofibers are surface modified.

12. The method of claim 2 wherein the carbon nanotubes are modified with a chemistry selected from the group consisting of:

carboxylate, ester, amine, amide, imine, imide, hydroxyl, ether, epoxide, phosphorus, ester carboxyl, anhydride, and nitrile.

13. The method of claim 2 wherein two or more carbon nanotubes act as a surfactant and are positioned between interfaces.

14. The method of claim 3 wherein two or more component nanofibers act as a surfactant and are positioned between a interfaces.

15. The method of claim 1 wherein the containing matrix of the dispersion is oil based.

16. The method of claim 1 wherein the containing matrix is aqueous.

17. The method of claim 15 wherein the oil base is selected from the group consisting of:

a poly α

-olefin, silicone oil with a water base and/or other type alcohol, an ether, a ketone, an ester, an amide, a sulfoxide, a sulfoxide, a hydrocarbon, petrol, diesel and a miscible mixture thereof.

18. The method of claim 15 wherein the oil based containing matrix comprises a base-oil and oil soluble additives.

19. The method of claim 18 wherein the base-oil is selected from the group consisting of:

mineral base oils, synthetic base oils, and base oils derived from biological materials.

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

adding a surfactant.

21. The method of claim 20 wherein the surfactant includes a mixture of non-ionic and ionic surfactants.

22. The method of claim 20 wherein the surfactant includes an ashless polymeric surfactant.

23. The method of claim 1 wherein the containing matrix is a monomer.

24. The method of claim 20 wherein the surfactant is dodecylbenzene sulfonic acid or sodium salt thereof.

25. The method of claim 2 wherein the carbon nanotubes have a mean diameter between 0.6 and 200 nanometers.

26. The method of claim 3 wherein the nanofibers have a mean diameter between 0.6 and 200 nanometers.

27. The method of claim 2 wherein the carbon nanotubes have a length of 100 nanometers to 1000 microns.

28. The method of claim 3 wherein the nanofibers have a length of 100 nanometers to 1000 microns.

29. The method of claim 2 wherein the carbon nanotubes have a ratio of length to diameter of 10 to 100000.

30. The method of claim 3 where the nanofibers have a ratio of length to diameter of 10 to 100000.

31. The method of claim 1 further comprising the steps of:

adding an additional dispersant to the mixture; and

,

re-mixing the mixture.

32. The method of claim 1 wherein the containing matrix is in a form as a gel or a paste obtained from a liquid petroleum liquid or an aqueous medium.

33. The method of claim 1 wherein the dispersion of nanostructures is uniform.

34. The method of claim 33 wherein the containing matrix is in the form of a grease.

35. The method of claim 20 wherein the surfactant is selected from the group consisting of:

an ionic surfactant and, a mixture of nonionic and ionic surfactants.

36. The method of claim 25 wherein a weight fraction of carbon nanotubes present is an isotropic mix in a region of 0.001 wt % to 30 wt % of nanostructures based on a total weight of the dispersion.

37. The method of claim 29 wherein a weight fraction of nanofibers present is an isotropic mix in a region of 0.001 wt % to 30 wt % of nanostructures based on a total weight of the dispersion.