Polymeric ionomer separation membranes and methods of use

1. A method of providing a fuel to an internal combustion engine, said method comprising:

selectively pervaporating an alcohol from a fuel feed mixture comprising the alcohol and a gasoline by contacting the fuel feed mixture with a separation membrane comprising a polymeric ionomer,

wherein the polymeric ionomer has a highly fluorinated backbone and recurring pendant groups according to the following formula (Formula I):

—O—R f —[—SO 2 —N − (Z + )—SO 2 —R—] m —[SO 2 ] n -Q

wherein:

R f is a perfluorinated organic linking group, excluding —CF 2 —[C(CF 3 )F—O—CF 2 —CF 2 ]—;

R is an organic linking group;

Z + is H + , a monovalent cation, or a multivalent cation;

Q is H, F, —NH 2 , —O − Y + , or —C x F 2x+1 ;

Y + is H + , a monovalent cation, or a multivalent cation;

x=1 to 4;

m=0 to 6; and

n=0 or 1;

with the proviso that at least one of m or n must be non-zero;

wherein the polymeric ionomer is more permeable to the alcohol than to the gasoline;

with the proviso that when m=0, Q is —O − Y + , and when Q is —O − Y + , m=0.

2. A cartridge suitable for use in a flex-fuel supply system of an internal combustion engine, said cartridge comprising a canister operatively adapted for connecting to the flex-fuel supply system, and the canister containing a pervaporation membrane for selectively separating an alcohol from a fuel feed mixture comprising the alcohol and a gasoline, with the membrane comprising a polymeric ionomer, wherein the polymeric ionomer has a highly fluorinated backbone and recurring pendant groups according to the following formula (Formula I):

—O—R f —[—SO 2 —N − (Z + )—SO 2 —R—] m —[SO 2 ] n -Q

wherein:

R f is a perfluorinated organic linking group, excluding —CF 2 —[C(CF 3 )F—O—CF 2 —CF 2 ]—;

R is an organic linking group;

Z + is H + , a monovalent cation, or a multivalent cation;

Q is H, F, —NH 2 , —O − Y + , or —C x F 2x+1 ;

Y + is H + , a monovalent cation, or a multivalent cation;

x=1 to 4;

m=0 to 6; and

n=0 or 1;

with the proviso that at least one of m or n must be non-zero;

wherein the polymeric ionomer is more permeable to the alcohol than to the gasoline;

with the proviso that when m=0, Q is —O − Y + , and when Q is —O − Y + , m=0.

3. The method according to claim 1 wherein the separation membrane further comprises:

a porous substrate on which the polymeric ionomer is disposed, with the porous substrate comprising opposite first and second major surfaces, and a plurality of pores,

wherein the polymeric ionomer forms a layer having a thickness in and/or on the porous substrate.

4. A flex-fuel supply system for an internal combustion engine, said supply system comprising a separation membrane for selectively pervaporating an alcohol from a fuel feed mixture comprising the alcohol and a gasoline, the composite membrane comprising:

a porous substrate comprising opposite first and second major surfaces, and a plurality of pores; and

a polymeric ionomer that forms a layer having a thickness in and/or on the porous substrate;

wherein the polymeric ionomer has a highly fluorinated backbone and recurring pendant groups according to the following formula (Formula I):

—O—R f —[—SO 2 —N − (Z + )—SO 2 —R—] m —[SO 2 ] n -Q

wherein:

R f is a perfluorinated organic linking group, excluding —CF 2 —[C(CF 3 )F—O—CF 2 —CF 2 ]—;

R is an organic linking group;

Z + is H + , a monovalent cation, or a multivalent cation;

Q is H, F, —NH 2 , —O − Y + , or —C x F 2x+1 ;

Y + is H + , a monovalent cation, or a multivalent cation;

x=1 to 4;

m=0 to 6; and

n=0 or 1;

with the proviso that at least one of m or n must be non-zero;

wherein the polymeric ionomer is more permeable to the alcohol than to the gasoline;

with the proviso that when m=0, Q is —O − Y + , and when Q is —O − Y + , m=0.

5. The method according to claim 3 wherein the porous substrate comprises a microporous layer.

6. The method according to claim 5 wherein the porous substrate comprises a macroporous layer.

7. The method according to claim 3 wherein the porous substrate has a thickness measured from one to the other of the opposite major surfaces in the range of from 5 μm up to and including 500 μm.

8. The method according to claim 3 wherein the porous substrate comprises pores having an average size in the range of from 0.5 nanometers (nm) up to and including 1000 82 m.

9. The method according to claim 1 further comprising a (meth)acryl-containing polymer.

10. The method according to claim 9 wherein the (meth)acryl-containing polymer is mixed with the polymeric ionomer.

11. The method according to claim 9 wherein the (meth)acryl containing polymer and polymeric ionomer are in separate layers.

12. The method according to claim 1 further comprising an epoxy polymer.

13. The method according to claim 12 wherein the epoxy polymer is mixed with the polymeric ionomer.

14. The method according to claim 12 wherein the epoxy polymer and polymeric ionomer are in separate layers.

15. The method according to claim 1 further comprising at least one of:

(a) an ionic liquid mixed with the polymeric ionomer; or

(b) an amorphous fluorochemical film disposed on separation membrane.

16. The method according to claim 15 wherein the amorphous fluorochemical film is a plasma-deposited fluorochemical film.

17. The method according to claim 15 wherein the amorphous fluorochemical film comprises an amorphous glassy perfluoropolymer having a Tg of at least 100° C.

18. The method according to claim 1 wherein R f is —(CF 2 ) t —wherein t is 1 to 6.

19. The cartridge according to claim 2 wherein R f is —(CF 2 ) t —wherein t is 1 to 6.

20. The flex-fuel supply system according to claim 4 wherein R f is —(CF 2 ) t —wherein t is 1 to 6.