CONDUCTIVE GREASE WITH ENHANCED THERMAL OR ELECTRICAL CONDUCTIVITY AND REDUCED AMOUNT OF CARBON PARTICLE LOADING

• US 20190315625A1
• Filed: 04/11/2019
• Published: 10/17/2019
• Est. Priority Date: 04/12/2018
• Status: Active Grant

• Current Assignee: South Dakota Board of Regents (University of South Dakota)
• Original Assignee: South Dakota Board of Regents (University of South Dakota)
• Inventors: Hong, Haiping, Widener, Christian A., Christensen, Gregory Lee
• Granted Patent: US 11,053,124 B2
• Time in Patent Office: Days
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 2202/02 Single-walled nanotubes
• CPC Class Codes: C01B 2202/06 Multi-walled nanotubes
• CPC Class Codes: C01B 2202/22 Electronic properties
• CPC Class Codes: C01B 2202/24 Thermal properties
• CPC Class Codes: C01B 32/174 Derivatisation; Solubilisation; Dispersion in solvents
• CPC Class Codes: C01B 35/023 Boron
• CPC Class Codes: C01P 2004/13 Nanotubes
• CPC Class Codes: C01P 2004/133 Multiwall nanotubes
• CPC Class Codes: C09K 5/10 Liquid materials
• CPC Class Codes: H01B 1/04 mainly consisting of carbon-silicon compounds, carbon or silicon
• CPC Class Codes: H01B 1/24 the conductive material comprising carbon-silicon compounds, carbon or silicon

Abstract

Disclosed herein is a conductive grease composition that includes a functionalized carbon nanomaterial and/or boron nanomaterial and a base oil. The nanomaterial and base oil forms hydrogen bond network in the disclosed composition. Because of the formed hydrogen bonds, the disclosed grease exhibits enhanced thermal or electrical conductivity. Also disclosed is a method to improve thermal or electrical conductivity of an existing grease composition.

Claims

1. A stable conductive grease composition comprising:

from about 25 wt-% to about 99 wt-% of a fluid;

from about 0.5 wt-% to about 20 wt-% of a nanomaterial;

wherein the nanomaterial is a carbon nanomaterial having one or more of a first functional group capable of forming a hydrogen bond or a boron nanomaterial;

wherein the fluid comprises one or more of a second functional group capable of forming a hydrogen bond.

2. The composition of claim 1, wherein the first and second functional group is a hydrophilic functional group.

3. The composition of claim 2, wherein the first functional group is an —

OH, —

NH, —

COOH, —

F, —

BH, —

O—

, —

N—

, or combination thereof.

4. The composition of claim 2, wherein the second functional group is an —

OH, —

NH, —

COOH, —

F, —

BH, —

O—

, —

N—

, or combination thereof.

5. The composition of claim 2, wherein the nanomaterial is carbon nanomaterial.

6. The composition of claim 5, wherein the carbon nanomaterial is carbon nanotube, carbon nanofiber, graphite particle, graphene particle, or combination thereof having at least one dimension that is less than 10,000 nanometers.

7. The composition of claim 1, wherein the nanomaterial is an OH functionalized carbon nanomaterial, a fluorine functionalized carbon nanomaterial, or a combination thereof.

8. The composition of claim 2, wherein the nanomaterial is boron nanomaterial.

9. The composition of claim 8, wherein the nanomaterial comprises single-walled carbon, multiple-walled carbon, single-walled boron, multiple-walled boron nanotube, or a combination thereof.

10. The composition of claim 1, wherein the fluid comprises a base oil, and wherein the base oil is an API Group I oil, API Group II oil, API Group III oil, API Group IV oil, API Group V oil, or a mixture thereof.

11. The composition of claim 1, wherein the base oil comprises an alkyl alcohol, alkylene glycols, polyol ester, or a combination thereof.

12. The composition of claim 1, wherein the composition further comprises a grease additive.

13. A method of preparing the composition of claim 1 comprising:

(a) combining the fluid and the nanomaterial;

(b) mixing the fluid and nanomaterial to form a grease composition; and

(c) passing the grease composition through a roller mill, an extruder, a manual stirrer, and/or a mechanical stirrer to form the conductive grease composition.

14. The method of claim 13, wherein the fluid is heated prior to, during, and/or after step (a).

15. The method of claim 13, wherein the fluid is not heated before or during mixing.

16. The method of claim 13, wherein the grease composition is heated during and/or after step (b).

17. A method of enhancing thermal or electric conductivity of a grease composition comprising:

adding into a grease composition a nanomaterial to form an improved grease composition, wherein the nanomaterial is a carbon nanomaterial having one or more of a first functional group or a boron nanomaterial capable of forming a hydrogen bond with a second functional group in the grease composition;

passing the improved grease composition through a roller mill, an extruder, a manual stirrer, and/or a mechanical stirrer to form the conductive grease composition.

18. The method of claim 17 further comprising a step of mixing the grease composition and the nanomaterial.

19. The method of claim 17, wherein the grease composition is heated prior to, during, and/or after the adding step.

20. The method of claim 17, wherein the improved grease composition comprises from about 0.5 wt-% to about 20 wt-% of the nanomaterial;

and wherein the nanomaterial comprises a single-walled carbon, multiple-walled carbon, single-walled boron, multiple-walled boron nanomaterial, or combination thereof.