Membranes for use in electrochemical sensors and associated devices

A membrane electrode assembly comprising

• an anode;
• a cathode comprising an oxygen reduction catalyst;
• and
• an ion exchange membrane comprising:
• a membrane material with a top surface and a bottom surface and comprising a glass fiber membrane material;
• and
• a protonic ionic liquid disposed at least between the top surface and the bottom surface of the membrane material;
• wherein the protonic ionic liquid is of Formula I:
• where R1, R2, and R3 are each independently H or a substituted or unsubstituted alkyl or cycloalkyl group, or where R1 and R2 taken together are a C2-C4 alkylene group;
• and
• X− is a sulfate, bisulfate, sulfonate, halide, carboxylate, phosphate, phosphonate, dicyanamide anion, perfluoroalkylsulfonate, perfluoroalkylsulfonamide anion, or bis(perfluoroalkylsulfonyl)imide anion;
• and
• wherein the glass fiber membrane material comprises glass fibers and at least one structural unit according to Formula IIa:
• wherein
• R4 and R5 are each independently H or a substituted or unsubstituted alkyl or cycloalkyl group, or where R4 and R5 taken together are a C4-C6 alkylene group;
• R6 is a substituted or unsubstituted alkylene or cycloalkylene group;
• R7 is hydroxyl, alkoxy, aryloxy, or G2;
• R8 is hydroxyl, alkoxy, aryloxy, or G3;
• G1, G2, and G3 are each independently an oxygen atom of the glass fiber, where G1, G2, and G3 are not the same oxygen atom;
• and
• Y− is a sulfate, bisulfate, sulfonate, halide, carboxylate, phosphate, phosphonate, dicyanamide anion, perfluoroalkylsulfonate, perfluoroalkylsulfonamide anion, or bis(perfluoroalkylsulfonyl)imides.