Compositions containing modified fullerenes
View Patent ↗Compositions containing modified fullerenes and their use, for example, as films for membranes in electrode assemblies for electrochemical cells and fuel cells such as fuel cells are described.
1. A composition comprising a mixture of (a) a polymer that consists essentially of
(i) one or more monomers selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, vinyl fluoride, vinylidine fluoride, trifluorethylene, chlorotrifluoroethylene, perfluoro(alkyl vinyl ether); and
(ii) one or more monomers selected from the group consisting of (1) fluorinated vinyl ethers comprising perfluorinated side chains that comprise cation exchange groups selected from the members of the group consisting of carboxylate, phosphonate, imide, sulfonamide and sulfonimide groups; and (2) monomers comprising a side chain represented by the structure of the following Formula (IV)
—(OCF 2 CFR 7 ) a —OCF 2 CFR 8 SO 3 X (IV)
wherein R 7 and R 8 are each independently selected from F or a perfluorinated alkyl group having 1 to 10 carbon atoms, a =0, 1 or 2, and X is H, an alkali metal, or NH 4 ; and
(b) one or more cyclofluoroalkylated fullerene compounds of Formula I
(C 60+2n )(CF 2 CR 1 R 2 ) w R 3 x R 4 y R 5 z (I)
wherein:
R 1 is F;
R 2 is OCF 3 , CF 3 , or Cl;
R 3 is a perfluoroalkyl or perfluoroalkylether group;
R 4 is a hydrocarbon alkyl or alkyl ether group;
R 5 is H;
n is an integer from 0 to 5;
w is an integer from 1 to 15;
x is an integer from 0 to 3+n;
y is an integer from 0 to 3+n; and
z is an integer from 0 to 3+n.
2. A film comprising the composition of claim 1 .
3. A membrane comprising the composition of claim 1 .
4. The membrane as recited in claim 3 wherein, in the cyclofluoroalkylated fullerene compound, R 2 is OCF 3 .
5. The membrane as recited in claim 3 wherein, in the cyclofluoroalkylated fullerene compound, R 2 is CF 3 .
6. The membrane as recited in claim 3 wherein, in the cyclofluoroalkylated fullerene compound, R 2 is Cl.
7. The membrane of claim 3 wherein the polymer is highly fluorinated.
8. The membrane of claim 3 wherein the polymer is perfluorinated.
9. The membrane of claim 3 wherein the cation exchange groups are selected from the members of the group consisting of sulfonamide and sulfonimide groups.
10. A membrane and electrode assembly comprising the membrane of claim 3 .
11. The membrane and electrode assembly of claim 10 wherein the electrode comprises a layer of electrically-conductive, catalytically-active particles.
12. The membrane and electrode assembly of claim 11 wherein the catalytically-active particles comprise one or more noble metals.
13. An electrochemical cell comprising an anode, a cathode and a membrane according to claim 3 .
14. An electrochemical cell according to claim 13 that further comprises an anode compartment and a cathode compartment, wherein the membrane further comprises an electrolyte and separates the anode compartment from the cathode compartment.
15. A fuel cell comprising an anode, a cathode and a membrane according to claim 3 .
16. A fuel cell according to claim 15 that further comprises an anode compartment and a cathode compartment, wherein the membrane further comprises an electrolyte and separates the anode compartment from the cathode compartment.
17. The membrane of claim 3 which further comprises a support prepared from a hydrocarbon polymer.
18. The membrane of claim 17 wherein the support comprises a highly fluorinated polymer or a perfluorinated polymer.
19. The membrane of claim 17 wherein the support comprises polytetrafluoroethylene (PTFE) or a copolymer of tetrafluoroethylene with a monomer selected from the group consisting of
20. The composition as recited in claim 1 wherein, in the cyclofluoroalkylated fullerene compound, and R 2 is OCF 3 .
21. The composition as recited in claim 1 wherein, in the cyclofluoroalkylated fullerene compound, and R 2 is CF 3 .
22. The composition as recited in claim 1 wherein, in the cyclofluoroalkylated fullerene compound, R 2 is Cl.