Graphene fiber for aerospace composites

Patent metadata

Field	Value
Publication number	US-10875986-B2
Application number	US-201514589036-A
Country	US
Kind code	B2
Filing date	Jan 5, 2015
Priority date	Jan 5, 2015
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

Graphene fibers made from a graphene film formed into an elongated fiber-like shape and composite materials made from the graphene fibers. The graphene film has amine groups formed on at least an outer surface of the graphene film and epoxide groups formed on at least one edge of the graphene film. The amine groups are formed in a functionalized area on the outer surface of the graphene film that is within about 10 microns from the at least one edge of the graphene film, or the functionalized area may extend the entire width of the graphene film. The graphene film may also have holes formed through the graphene film. The elongated fiber-like shapes may be the graphene film in a rolled spiral orientation or the graphene film in a twisted formation.

First claim

The invention claimed is:

1. A graphene fiber comprising a single graphene film having a width in the range of about 50 microns to about 500 microns from a first edge to a second edge, the graphene film formed into an elongated fiber-like shape having a rolled spiral orientation with a diameter of about 1 to about 7 microns, the graphene fiber having amine groups bound to an outer surface of the graphene film only in a functionalized area on the outer surface that extends a length of the graphene film and about 10 microns in from the first edge of the graphene film and epoxide groups formed on the first edge of the graphene film, the amine groups in the functionalized area on the outer surface of the graphene film remaining exposed when the graphene film is in the rolled spiral orientation.

2. The graphene fiber of claim 1 , wherein the graphene film has a linear density of epoxide groups formed on the first edge of about 7,000 to about 700,000 groups per millimeter.

3. The graphene fiber of claim 2 , wherein the amine groups in the functionalized area on the outer surface of the graphene film have a surface density of about 4.0E10 to about 2.0E12 groups per square millimeter of the functionalized area.

4. The graphene fiber of claim 1 , wherein about 0.1% to about 10% of carbon atoms at the first edge of the graphene film have epoxide groups bonded thereto.

5. The graphene fiber of claim 4 , wherein about 0.1% to about 5.0% of carbon atoms in the functionalized area of the graphene film have amine groups bonded thereto.

6. The graphene fiber of claim 1 , wherein the graphene fiber has a circumference of about 3 to about 22 microns.

7. The graphene fiber of claim 6 , wherein the elongated fiber-like shape has a center hollow area having a diameter of less than 500 nanometers.

8. The graphene fiber of claim 7 , wherein the spiral orientation comprises the single graphene film rolled at an angle greater than 0.0 degrees and less than 0.6 degrees and overlapping layers of the graphene film such that the functionalized area on the outer surface of the graphene film remains exposed.

9. The graphene fiber of claim 1 , wherein the graphene film further comprises at least one hole formed through the graphene film.

10. The graphene fiber of claim 9 , wherein the at least one hole is substantially circular and has a diameter of 1-2 nanometers.

11. The graphene fiber of claim 9 , wherein the graphene film has a density of holes in the range of about 4E7 to about 4E10 holes per square millimeter, or about one hole per 1,000 to 1 million carbon atoms.

12. The graphene fiber of claim 9 , wherein about 12-80 carbon atoms are removed from the graphene film to form each of the holes.

13. The graphene fiber of claim 9 , wherein the amine groups on the outer surface of the graphene film have a surface density of about 4.0E10 to about 2.0E12 groups per square millimeter of the outer surface of the graphene film.

14. The graphene fiber of claim 13 , wherein the graphene film has a linear density of epoxide groups formed on all edges of the graphene film of about 7,000 to about 700,000 groups per millimeter.

15. The graphene fiber of claim 13 , wherein about 0.1% to about 10% of carbon atoms at all edges of the graphene film have epoxide groups bonded thereto.

16. A composite material comprising the graphene fiber of claim 1 and a matrix material.

17. A method of increasing strength of a composite material, the method comprising:
forming a graphene fiber comprising a single graphene film having a width in the range of about 50 microns to about 500 microns from a first edge to a second edge, the graphene fiber formed into an elongated fiber-like shape having a rolled spiral orientation with a diameter of about 1 to about 7 microns, the graphene fiber having amine groups bound to an outer surface of the graphene film only in a functionalized area on the outer surface that extends a length of the graphene film and about 10 microns in from the first edge of the graphene film and epoxide groups formed on the first edge of the graphene film, the amine group in the functionalized area on the outer surface of the graphene film remaining exposed in the fiber-like shape;
combining a matrix material with a plurality of the graphene fibers to form a prepreg material; and
curing the prepreg material to form the composite material.

18. The method of claim 17 , wherein the step of forming the graphene fiber further comprises forming the graphene fiber with a circumference of about 3 to about 22 microns, and a center hollow area having a diameter of less than 500 nanometers.

19. The method of claim 17 , wherein the step of forming the graphene fiber further comprises maintaining a tension in the graphene film at about 0.001 N per meter of film width.

20. The method of claim 17 , wherein the step of forming the graphene fiber further comprises forming at least one hole in the graphene film.

21. The method of claim 20 , wherein the at least one hole is formed in a substantially circular shape with a diameter of 1-20 nanometers.

22. The method of claim 21 , wherein the graphene film has a density of holes in the range of about 4E7 to about 4E10 holes per square millimeter, or about one hole per 1,000 to 1 million carbon atoms.

23. The method of claim 17 , further comprising combining carbon fiber with the graphene fiber to form the prepreg material.

24. A graphene fiber comprising a single graphene film having a width in the range of about 50 microns to about 500 microns from a first edge to a second edge, the graphene film formed into an elongated fiber-like shape, the graphene film having amine groups bound to an outer surface of the graphene film only in a functionalized area on the outer surface that extends a length of the graphene film and about 10 microns in from the first edge of the graphene film and remaining exposed in the elongated fiber-like shape, and epoxide groups formed only at the first edge of the graphene film.

25. The graphene fiber of claim 24 , wherein the elongated fiber-like shape comprises the graphene film in a rolled spiral orientation comprising the graphene film rolled at an angle greater than 0.0 degrees and less than 0.6 degrees.

26. The graphene fiber of claim 24 , wherein the first edge of the graphene film that is within the functionalized area has a linear density of epoxide groups of about 7,000 to about 700,000 groups per millimeter, such that about 0.1% to about 10% of carbon atoms at the first edge of the graphene film have epoxide groups bonded thereto, and the outer surface of the graphene film that is within the functionalized area has a surface density of amine groups of about 4.0E10 to about 2.0E12 groups per square millimeter of the functionalized area, such that about 0.1% to about 5.0% of carbon atoms in the functionalized area of the graphene film have amine groups bonded thereto.

Assignees

• Boeing Co

Inventors

• Humfeld Keith Daniel
• Griess Kenneth H

Classifications

• C08J5/247 Primary

  using fibres of at least two types · CPC title

• C08J5/248

  using pre-treated fibres · CPC title

• C08J5/06

  using pretreated fibrous materials · CPC title

• C08J2300/24

  Thermosetting resins · CPC title

• C08J5/005

  Reinforced macromolecular compounds with nanosized materials, e.g. nanoparticles, nanofibres, nanotubes, nanowires, nanorods or nanolayered materials · CPC title