PREPARATION OF A CARBON NANOMATERIAL USING A REVERSE MICROEMULSION

• US 20100092370A1
• Filed: 10/10/2008
• Published: 04/15/2010
• Est. Priority Date: 10/10/2008
• Status: Active Grant

• Current Assignee: Headwaters technology innovation group inc. (Seven Group Holdings Limited)
• Original Assignee: Headwaters Technology Innovation, LLC
• Inventors: Zhou, Bing, Zhang, Cheng
• Granted Patent: US 8,318,122 B2
• Time in Patent Office: Days
• US Class Current: 423/448
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 32/05 Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30

Abstract

Powdered, amorphous carbon nanomaterials are formed from a carbon precursor in reverse microemulsion that includes organic solvent, surfactant and water. Methods for manufacturing amorphous, powdered carbon nanomaterials generally include steps of (1) forming a reverse microemulsion including at least one non-polar solvent, at least one surfactant, and at least one polar solvent, (2) adding at least one carbon precursor substance to the reverse microemulsion, (3) reacting the at least one carbon precursor substance so as to form an intermediate carbon nanomaterial, (4) separating the intermediate amorphous carbon nanomaterial from the reverse microemulsion, and (5) heating the intermediate amorphous carbon nanomaterial for a period of time so as to yield an amorphous, powdered carbon nanomaterial. Amorphous, powdered carbon nanomaterials manufactured according to the present disclosure typically have a surface area of at least 500 m²/g, a graphitic content of at least 25%, and a conductivity of at least 150 S/m.

Claims

1. A method for manufacturing a carbon nanomaterial, the method comprising,

forming a reverse microemulsion comprising at least one non-polar solvent, at least one surfactant, and at least one polar solvent;

adding at least one carbon precursor substance to the reverse microemulsion;

reacting the at least one carbon precursor substance so as to form an intermediate carbon nanomaterial;

separating the intermediate carbon nanomaterial from the reverse microemulsion; and

heating the intermediate carbon nanomaterial for a period of time so as to yield a carbon nanomaterial in which at least a portion of the carbon is graphitic.

2. A method as recited in claim 1, wherein the at least one organic solvent, the at least one surfactant, and the water are added in a non-polar solvent:

surfactant;

polar solvent ratio between about 10;

10;

1 and about 20;

1;

1.

3. A method as recited in claim 2, wherein the non-polar solvent:

surfactant;

polar solvent ratio is about 10;

2;

1.

4. A method as recited in claim 1, wherein the non-polar solvent includes at least one of hexanes, cyclohexane, benzene, diethyl ether, trichloromethane, ethyl acetate, methyl methacrylate, toluene, phenyl ethers, or N-methyl pyrrolidone, and combinations thereof.

5. A method as recited in claim 1, wherein the surfactant includes at least one of an octylphenol ethoxylate, a phosphonic acid, a phosphinic acid, a polyethylene glycol monoalkyl ether, or a sulfonic acid, and combinations thereof.

6. A method as recited in claim 1, wherein the polar solvent includes at least one of water, short-chain alcohols, dioxane, tetrahydrofuran, dichloromethane, acetone, acetonitrile, dimethylformamide, dimethyl sulfoxide, acetic acid, or formic acid, and combinations thereof.

7. A method as in claim 1, wherein the carbon precursor substance includes at least one of resorcinol-formaldehyde, phenol resin, melamine-formaldehyde, furfuryl alcohol, acrylonitrile, and combinations thereof.

8. A method as in claim 1, the heating further comprising carbonizing the amorphous carbon precursor material a temperature between about 500°

C. and about 2000°

C.

9. A method as in claim 1, the heating further comprising carbonizing the amorphous carbon precursor material a temperature between about 700°

C. and about 1500°

C.

10. A method as in claim 1, the heating further comprising carbonizing the amorphous carbon precursor material for a period of time between about 1 hour and about 6 hours.

11. An amorphous, powdered carbon nanomaterial manufactured according to the method of claim 1, the amorphous, powdered carbon nanomaterial having a surface area of at least 500 m²/g, a graphitic content of at least 25%, and a conductivity of at least 150 S/m.

16. A method as in claim 10, the heating further comprising carbonizing the amorphous carbon precursor material a temperature between about 500°

C. and about 2000°

C.

12. A method for manufacturing an amorphous carbon nanomaterial using a reverse microemulsion process, the method comprising,

forming a reverse microemulsion by vigorously stirring a solution containing at least one organic solvent, at least one surfactant, and water, wherein the reverse microemulsion includes a plurality of micelles, each of the plurality of micelles comprising:

a water droplet and a plurality of surfactant molecules suspended in the organic solvent;

adding at least one carbon precursor substance to the reverse microemulsion, wherein the at least one carbon precursor substance sequesters into the water droplets;

adding at least one carbon precursor substance to the plurality of micelles while stirring vigorously;

adding at least one catalyst to the reverse microemulsion containing the plurality of micelles, wherein the at least one catalyst sequesters into the water droplets;

reacting the at least one carbon precursor substance in the presence of the catalyst for a period of time between about 1 hour and about 5 hours while stirring and maintaining a temperature between about 50°

C. and about 100°

C. so as to form an intermediate amorphous carbon nanomaterial;

separating the intermediate amorphous carbon nanomaterial from the reverse microemulsion; and

heating the intermediate amorphous carbon nanomaterial for a period of time between about 1 hour and about 6 hours in the presence of an inert atmosphere so as to yield an amorphous, powdered carbon nanomaterial having a surface area of at least 500 m²/g, a graphitic content of at least 25%, and a conductivity of at least 150 S/m.

15. A method as recited in claim 15, wherein the surfactant includes at least one of an octylphenol ethoxylate, a phosphonic acid, a phosphinic acid, a polyethylene glycol monoalkyl ether, or a sulfonic acid, and combinations thereof.

13. A method as recited in claim 15, wherein the at least one organic solvent, the at least one surfactant, and the water are added in a solvent:

surfactant;

water ratio between about 10;

10;

1 and about 20;

1;

1.

14. A method as recited in claim 15, wherein the organic solvent includes at least one of hexanes, cyclohexane, benzene, diethyl ether, trichloromethane, ethyl acetate, methyl methacrylate, toluene, phenyl ethers, or N-methyl pyrrolidone, and combinations thereof.

17. A carbon nanomaterial, comprising:

an amorphous, powdered carbon nanomaterial having a surface area of at least 500 m²/g, a graphitic content of at least 25%, and a conductivity of at least 150 S/m.

18. A carbon nanomaterial as in claim 17, wherein the amorphous, powdered carbon nanomaterial has a surface area of at least 800 m²/g.

19. A carbon nanomaterial as in claim 17, wherein the amorphous, powdered carbon nanomaterial has a surface area of at least 1000 m²/g.

20. A carbon nanomaterial as in claim 17, wherein the amorphous, powdered carbon nanomaterial has a graphitic content of at least 75%.

21. A carbon nanomaterial as in claim 17, wherein the amorphous, powdered carbon nanomaterial has a graphitic content of at least 80%.

22. A carbon nanomaterial as in claim 17, wherein the amorphous, powdered carbon nanomaterial has a conductivity of at least 175 S/m.

23. A carbon nanomaterial as in claim 17, wherein the amorphous, powdered carbon nanomaterial has a conductivity of at least 200 S/m.

24. A carbon nanomaterial as in claim 17, wherein the amorphous, powdered carbon nanomaterial has a surface area of at least 1000 m²/g, a graphitic content of at least 80%, and a conductivity of at least 225 S/m.