Polymeric ionomer separation membranes and methods of use

A separation membrane for selectively pervaporating a first liquid from a feed mixture comprising the first liquid and a second liquid, the separation membrane comprising:

• a polymeric ionomer in the form of a layer having a thickness, with the polymeric ionomer having a highly fluorinated backbone and recurring pendant groups according to the following formula (Formula I):
• —O—Rf—[—SO2—N−(Z+)—SO2—R—]m—[SO2]n-Q
• wherein:
• Rf is a perfluorinated organic linking group;
• R is an organic linking group;
• Z+ is H+, a monovalent cation, or a multivalent cation;
• Q is H, F, —NH2, —O−Y+, or —CxF2x+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 first liquid than the second liquid, Q is not —O−Y+ when m=0, and m is not 0 when Q is —O−Y+.

A combination of a gasoline fuel system and a separation membrane for selectively pervaporating a first liquid from a feed mixture comprising the first liquid and a second liquid, with the first liquid being a high octane compound, the second liquid being gasoline, and the separation membrane comprising:

• a polymeric ionomer in the form of a layer having a thickness,
• wherein the polymeric ionomer is more permeable to the high octane compound than the gasoline and has a highly fluorinated backbone and recurring pendant groups according to the following formula (Formula I):
• —O—Rf—[—SO2—N−(Z+)—SO2—R—]m—[SO2]n-Q
• wherein:
• Rf is a perfluorinated organic linking group;
• R is an organic linking group;
• Z+ is H+, a monovalent cation, or a multivalent cation;
• Q is H, F, —NH2, —O−Y+, or —CxF2x+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.