Electrically conductive materials for heating and deicing airfoils

• US 10,464,680 B2
• Filed: 08/30/2016
• Issued: 11/05/2019
• Est. Priority Date: 08/30/2016
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Kinlen, Patrick J., Young, Kenneth W.
• Primary Examiner(s): Green, Richard R.
• Assistant Examiner(s): Frazier, Brady W
• Application Number:
  US15/252,056
• Publication Number:
  US 20180057176A1
• Time in Patent Office: 1,162 Days
• Field of Search: 244134 D, 252500, 252502, 4284111
• CPC Class Codes: B64C 27/46 Blades
• CPC Class Codes: B64D 15/12 by electric heating electric heating elements in general H05B
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: H05B 2203/037 Heaters with zones of different power density
• CPC Class Codes: H05B 2214/02 Heaters specially designed for de-icing or protection against icing
• CPC Class Codes: H05B 2214/04 Heating means manufactured by using nanotechnology
• CPC Class Codes: H05B 3/145 Carbon only, e.g. carbon black, graphite
• CPC Class Codes: H05B 3/146 Conductive polymers, e.g. polyethylene, thermoplastics
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

Composite airfoils of the present disclosure comprise a root section including a first surface. The airfoils comprise an intermediate section having a first surface and coupled with the root section at a first end. The airfoils comprise a tip section having a first surface and coupled at a first end with a second end of the intermediate section. The airfoils comprise a conductive material layer adjacent at least one of the first surface of the root section, the first surface of the intermediate section, and the first surface of the tip section. The conductive material comprises a first polymer, a second polymer, and a sulfonic acid.

Claims

1. A composite airfoil comprising:

a root section;

an intermediate section coupled with the root section;

a tip section coupled with the intermediate section; and

a conductive material layer applied over the root section, the intermediate section, and of the tip section, the conductive material comprising;

a carbon allotrope material sheet;

an electrically conductive polymer deposited over the carbon allotrope material sheet; and

a sulfonic acid deposited over the carbon allotrope material sheet.

2. The airfoil of claim 1, wherein the conductive material layer is applied on the intermediate section, wherein the intermediate section is a spar.

3. The airfoil of claim 1, wherein the conductive material is an electrode.

4. The airfoil of claim 1, further comprising an electrode attached to the conductive material layer.

5. The airfoil of claim 1, further comprising a wear-resistant material layer adjacent the conductive material layer.

6. The airfoil of claim 5, wherein the wear-resistant material layer comprises nickel, titanium, or mixtures thereof.

7. The airfoil of claim 1, wherein the carbon allotrope material sheet comprises multi-walled carbon nanotubes, single-walled carbon nanotubes, graphenes, polycarbonates, fullerenes, or combinations thereof.

8. The airfoil of claim 1, wherein the conductive material has an Ω

/□

value between about 1.2× and

about 20×

higher than an Ω

/□

value of the carbon allotrope material sheet.

9. The airfoil of claim 1, wherein the sulfonic acid comprises a naphthyl sulfonic acid, an anthracenyl sulfonic acid, a pyrenyl sulfonic acid, or mixtures thereof.

10. The airfoil of claim 1, wherein the polymer comprises a polyaniline, a poly(ethylenedioxythiophene), a poly(styrenesulfonate), or mixtures thereof.

11. The airfoil of claim 1, further comprising a second polymer.

12. The airfoil of claim 11, wherein the second polymer comprises a polyurethane, a polyvinyl butyral, a polyacrylate, an epoxy, a glycidyl-Si—

Zr-containing solgel, a polyester, a phenoxy resin, a polysulfide, or mixtures thereof.

13. The airfoil of claim 12, wherein the second polymer is a polyurethane or a polyvinyl butyral.

14. The airfoil of claim 1, wherein the conductive material layer has a thickness between about 0.1 μ

m and about 10 μ

m and a resistivity of between about 1e+4Ω

/□ and

about 1e+8 Ω

/□

.

15. The airfoil of claim 1, wherein the polymer is a mixture of a poly(ethylenedioxythiophene) and a poly(styrenesulfonate), wherein the mixture is between about 1 wt % and about 50 wt % of the conductive material layer.

25. The composite airfoil of claim 1, wherein the conductive polymer and the sulfonic acid are deposited by flow-coating, drop-casting, dipping, spraying, brush coating, spin coating, roll coating, or doctor-blade coating.

16. A method of forming a conductive material disposed on a composite airfoil, the method comprising:

depositing a conductive material onto an airfoil to form a conductive material layer, the airfoil having a root section, an intermediate section coupled with the root section, and a tip section coupled with the root section, the conductive material layer comprising an electrically conductive polymer and a sulfonic acid disposed over a carbon allotrope material sheet; and

curing the conductive material layer.

17. The method of claim 16, further comprising:

forming the carbon allotrope material sheet by depositing an carbon allotrope material onto the airfoil and curing the carbon allotrope material.

18. The method of claim 17, wherein the carbon allotrope material comprises carbon nanotubes, graphenes, fullerenes, polycarbonates, or combinations thereof.

19. The method of claim 16, further comprising rinsing the conductive material layer with a rinsing agent.

20. The method of claim 19, wherein the rinsing agent comprises isopropyl alcohol, p-Toluenesulfonic acid, acetone, methanol, hydrates thereof, solvates thereof, or mixtures thereof.

21. The method of claim 16, further comprising dissolving the electrically conductive polymer in a solvent, wherein the solvent comprises a xylene, a benzene, a toluene, dimethyl sulfoxide, water, or mixtures thereof.

22. The method of claim 16, wherein the conductive material is deposited to a thickness between about 0.1 μ

m and about 10 μ

m.

23. The method of claim 16, wherein curing comprises raising the temperature of the conductive material layer to a peak curing temperature between about room temperature and about 200°

C.

24. The method of claim 16, wherein depositing the conductive material onto the airfoil comprises spin-coating the conductive material onto the airfoil at a rate of between about 100 rpm and about 4,000 rpm.

26. The method of claim 16, wherein the conductive material is deposited by flow-coating, drop-casting, dipping, spraying, brush coating, spin coating, roll coating, or doctor-blade coating.