Membranes for use in electrochemical sensors and associated devices

Patent metadata

Field	Value
Publication number	US-2016146751-A1
Application number	US-201514946485-A
Country	US
Kind code	A1
Filing date	Nov 19, 2015
Priority date	Nov 26, 2014
Publication date	May 26, 2016
Grant date	—

Abstract

A membrane is provided, as well as membrane electrode assemblies and sensors utilizing the membrane of the present technology. The membrane includes a membrane material with a top surface and a bottom surface; and a protonic ionic liquid disposed at least between the top surface and the bottom surface of the membrane material where the protonic ionic liquid is of Formula I.

First claim

What is claimed is:

1 . A membrane electrode assembly comprising
an anode; a cathode comprising an oxygen reduction catalyst; and a membrane comprising:
a membrane material with a top surface and a bottom surface; 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 R 1 , R 2 , and R 3 are each independently H or a substituted or unsubstituted alkyl or cycloalkyl group, or where R 1 and R 2 taken together are a C 2 -C 4 alkylene group; and
X − is a sulfate, bisulfate, sulfonate, halide, carboxylate, phosphate, phosphonate, dicyanamide anion, perfluoroalkylsulfonate, perfluoroalkylsulfonamide anion, or bis(perfluoroalkylsulfonyl)imide anion.

2 . The membrane electrode assembly of claim 1 , wherein
R 1 , R 2 , and R 3 are each independently H or an unsubstituted alkyl group.

3 . The membrane electrode assembly of claim 1 , wherein
R 1 , R 2 , and R 3 are each independently H, methyl, ethyl, n-propyl, or i-propyl.

4 . The membrane electrode assembly of claim 1 , wherein
X − is triflate, nonafluorobutylsulfonate, or a perfluoroalkylsulfonate, or X − is a sulfonate functional group of the membrane.

5 . The membrane electrode assembly of claim 1 , wherein the membrane material comprises one or more of an expanded polytetrafluoroethylene, a polypropylene, a glass fiber membrane material, a cellulose membrane material, a polystyrene, a polyamide, a polybenzimidazole, or a tetrafluoroethylene-perfluoroalkylvinylether,
wherein the expanded PTFE, polypropylene, polystyrene, polyamide, polybenzimidazole, and/or tetrafluoroethylene-perfluoroalkylvinylether optionally includes sulfonic acid groups, carboxylate groups, phosphate groups, phosphonate groups, or combinations of any two or more thereof.

6 . The membrane electrode assembly of claim 1 , wherein the membrane comprises a glass fiber membrane material.

7 . The membrane electrode assembly of claim 6 , wherein the glass fiber membrane material comprises glass fibers and at least one structural unit according to Formula IIa:

wherein
R 4 and R 5 are each independently H or a substituted or unsubstituted alkyl or cycloalkyl group, or where R 4 and R 5 taken together are a C 4 -C 6 alkylene group;
R 6 is a substituted or unsubstituted alkylene or cycloalkylene group;
R 7 is hydroxyl, alkoxy, aryloxy, or G 2 ;
R 8 is hydroxyl, alkoxy, aryloxy, or G 3 ;
G 1 , G 2 , and G 3 are each independently an oxygen atom of the glass fiber, where G 1 , G 2 , and G 3 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.

8 . The membrane electrode assembly of claim 7 , wherein the glass fiber membrane material further comprises at least one structural unit according to Formula IIb:

9 . The membrane electrode assembly of claim 7 , wherein
R 4 and R 5 are each independently H or an unsubstituted alkyl or aryl group; and R 6 is an unsubstituted alkylene group.

10 . The membrane electrode assembly of claim 7 , wherein
R 4 and R 5 are each independently H or an unsubstituted alkyl group; R 6 is an unsubstituted alkylene group; R 7 is alkoxy or G 2 ; and R 8 is alkoxy or G 3 .

11 . The membrane electrode assembly of claim 7 , wherein the glass fiber membrane material comprises a plurality of structural units according to Formula IIa.

12 . The membrane electrode assembly of claim 8 , wherein the glass fiber membrane material comprises a plurality of structural units according to Formula IIb.

13 . The membrane electrode assembly of claim 1 , wherein a thickness defined by the top surface and the bottom surface of the glass fiber membrane material is from about 10 μm to about 400 μm.

14 . The membrane electrode assembly of claim 1 , wherein
the membrane material comprises a tetrafluoroethylene-perfluoroalkylvinylether copolymer wherein the copolymer comprises sulfonic acid groups.

15 . The membrane electrode assembly of claim 1 , wherein membrane has from about 20 wt % to about 90 wt % of the protonic ionic liquid.

16 . The membrane electrode assembly of claim 1 , wherein the membrane further comprises an ion conducting material not of Formula I.

17 . The membrane electrode assembly of claim 1 , wherein the membrane does not comprise a polymer.

18 . The membrane electrode assembly of claim 1 , wherein the membrane is an ion exchange membrane.

19 . An electrochemical carbon monoxide sensor for use in a gas or fire detector,
the sensor comprising a first sidewall; a second sidewall; a top wall; and a bottom wall; the first sidewall, the second sidewall, the top wall and the bottom wall defining a containment region and containing therein a membrane electrode assembly of claim 1 ; wherein:
the top wall comprises a gaseous diffusion aperture;
the membrane permits ion transport between the anode and the cathode; and
the membrane prevents electron conduction between the anode and the cathode.

20 . The electrochemical carbon monoxide sensor of claim 19 , wherein the membrane comprises a glass fiber membrane material.

Assignees

• Gentex Corp

Inventors

• Nemes Joel C

Classifications

• C08G2261/3241

  containing one or more nitrogen atoms as the only heteroatom, e.g. carbazole · CPC title

• C08G61/123

  derived from five-membered heterocyclic compounds · CPC title

• H01M8/0293

  Matrices for immobilising electrolyte solutions · CPC title

• C08J5/2206

  based on organic and/or inorganic macromolecular compounds · CPC title

• G01N33/004

  CO or CO2 · CPC title