HYDROPHOBIC FLUORINATED POLYELECTROLYTE COMPLEX FILMS AND ASSOCIATED METHODS

• US 20100173224A1
• Filed: 03/19/2010
• Published: 07/08/2010
• Est. Priority Date: 03/26/2004
• Status: Active Grant

• Current Assignee: Florida State University Research Foundation, Inc. (State University System of Florida)
• Original Assignee: Florida State University Research Foundation, Inc. (State University System of Florida)
• Inventors: Schlenoff, Joseph B.
• Granted Patent: US 8,071,255 B2
• Time in Patent Office: Days
• US Class Current: 429/494
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C08F 8/20 Halogenation
• CPC Class Codes: Y10T 428/3154 Of fluorinated addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31544 Addition polymer is perhalogenated

Abstract

A fuel cell comprising a proton transporting membrane is provided. The proton transporting membrane comprises a polyelectrolyte film comprising a multilayer comprising an interpenetrating network of a net positively charged polyelectrolyte polymer comprising repeat units with at least two fluorine atoms and a net negatively charged polyelectrolyte polymer comprising repeat units with at least two fluorine atoms, and further comprising a fluorinated counterion within the multilayer.

Claims

1. A fuel cell comprising a proton transporting membrane, the proton transporting membrane comprising a polyelectrolyte film comprising a multilayer comprising an interpenetrating network of a net positively charged polyelectrolyte polymer comprising repeat units with at least two fluorine atoms and a net negatively charged polyelectrolyte polymer comprising repeat units with at least two fluorine atoms, and further comprising a fluorinated counterion within the multilayer.

2. The fuel cell of claim 1 wherein the fluorinated counterion comprises at least two fluorine atoms.

3. The fuel cell of claim 1 wherein the fluorinated counterion comprises a perfluorinated counterion.

4. The fuel cell of claim 1 wherein the perfluorinated counterion comprises a fluorinated alkanesulfonic acid, a fluorinated alkanecarboxylic acid, or both;

an alkane component of the acid having a molecular weight up to 300 g per mole; and

at least four fluorine atoms.

5. The fuel cell of claim 1 wherein the polyelectrolyte film is on a surface of a porous support.

6. The fuel cell of claim 1 wherein the polyelectrolyte film is on a surface of a porous support, the porous support comprising pores that are less than 10 micrometers.

7. The fuel cell of claim 1 wherein the interpenetrating network has a thickness below 1000 nm.

8. The fuel cell of claim 1 wherein the interpenetrating network has a thickness below 100 nm.

9. The fuel cell of claim 1 wherein the proton transporting membrane separates two compartments, each compartment comprising an acidic solution comprising perfluorinated counterion.

10. The fuel cell of claim 9 wherein the perfluorinated counterion comprises a fluorinated alkanesulfonic acid, a fluorinated alkanecarboxylic acid, or both;

an alkane component of the acid having a molecular weight up to 300 g per mole; and

at least four fluorine atoms.

11. The fuel cell of claim 1 wherein the net positively charged polyelectrolyte polymer and the net negatively charged polyelectrolyte polymer are independently selected from the group consisting of polyolefins, polyamines, polyamides, polyethers, polyesters, polyimides, polysulfones, polyaryls, polyphenols, polyaramides, and copolymers thereof.

12. The fuel cell of claim 11 wherein the net positively charged polyelectrolyte polymer and the net negatively charged polyelectrolyte polymer comprise repeat units having the structure:

13. The fuel cell of claim 11 wherein the positively charged polyelectrolyte polymer comprises a repeat unit comprising an allyl group having the structure:

14. The fuel cell of claim 1 wherein the net positively charged polyelectrolyte polymer and the net negatively charged polyelectrolyte polymer are polyolefins having vinyl groups.

15. The fuel cell of claim 14 wherein the vinyl group is an allyl group.

16. The fuel cell of claim 1 wherein the net positively charged polyelectrolyte polymer has the structure:

17. The fuel cell of claim 1 wherein the net negatively charged polyelectrolyte polymer has the structure:

18. The fuel cell of claim 1 wherein the polyelectrolyte film further comprising particles having a size in the range of about 1 nanometer to about 10 micrometers.

19. The fuel cell of claim 18 wherein the particles are selected from the group consisting of silicon dioxide, aluminum oxide, titanium dioxide, iron oxide, zirconium oxide, vanadium oxide, clay minerals, carbon fibers, carbon nanotubes, and charged fluorinated particles.

20. The fuel cell of claim 19 wherein the particle is the clay mineral, and the clay mineral comprises attapulgite clay.

21. The fuel cell of claim 1 wherein the polyelectrolyte film is formed on the surface of a film of poly perfluorinated sulfonated ionomer, wherein the poly perfluorinated sulfonated ionomer film has a thickness between 2 micrometers and 1000 micrometers.

22. A fuel cell comprising a proton transporting membrane, the proton transporting membrane comprising a film comprising multilayers of a charged polyelectrolyte polymer comprising repeat units with at least two fluorine atoms electrostatically complexed with a perfluorinated charged particle comprising repeat units with at least two fluorine atoms, wherein the charge of the polyelectrolyte polymer is opposite that of the charge of the perfluorinated charged particle;

wherein the multilayers comprise layer pairs and each layer pair comprises the polyelectrolyte polymer electrostatically complexed with the perfluorinated charged particle, and the multilayers are created from the polyelectrolyte polymer and an aqueous dispersion or suspension of the fluorinated polymer particles.

23. The fuel cell of claim 22 wherein the perfluorinated charged particle comprises polytetrafluoroethylene.

24. The fuel cell of claim 22 wherein the polyelectrolyte polymer comprises a plurality of charged repeat units with at least two fluorine atoms.