Composite membranes, methods of making same, and applications of same

Patent metadata

Field	Value
Publication number	US-2016380296-A1
Application number	US-201615161838-A
Country	US
Kind code	A1
Filing date	May 23, 2016
Priority date	Oct 27, 2010
Publication date	Dec 29, 2016
Grant date	—

Abstract

A method of fabricating a composite membrane, includes the steps of: forming a first solution comprising a charged polymer and a first uncharged polymer having a repeat unit of a formula of:

where each of X and Y is a non-hydroxyl group; forming a second solution comprising a second uncharged polymer; electrospinning, separately and simultaneously, the first solution and the second solution to form a dual fiber mat; and processing the dual fiber mat to form the composite membrane.

First claim

What is claimed is:

1 . A method of fabricating a composite membrane, comprising:
forming at least one first solution comprising a charged polymer and a first uncharged polymer having a repeat unit of a formula of:

 wherein each of X and Y is a non-hydroxyl group;
forming at least one second solution comprising a second uncharged polymer;
electrospinning, separately and simultaneously, the first solution and the second solution to form a fiber mat comprising first polymer fibers formed from the first solution and second polymer fibers formed from the second solution; and
processing the fiber mat to form the composite membrane.

2 . The method of claim 1 , wherein the charged polymer is selected from perfluorosulfonic acid (PFSA) polymer and perfluoro imide acid (PFIA) polymer.

3 . The method of claim 2 , wherein the charged polymer is selected from Nafion® and Aquivion®.

4 . The method of claim 1 , wherein each of X and Y is fluoride, and the first uncharged polymer is polyvinylidene difluoride (PVDF) or a copolymer of PVDF.

5 . The method of claim 1 , wherein X is hydrogen group, Y is a carboxylic acid group, and the first uncharged polymer is poly(acrylic acid) (PAA).

6 . The method of claim 1 , wherein the second uncharged polymer is polyvinylidene difluoride (PVDF) or polyphenylsulsulfone (PPSU).

7 . The method of claim 1 , wherein the step of processing the dual fiber mat to form the composite membrane comprises:
compressing the dual fiber mat; and exposing the dual fiber mat to solvent vapor to soften and flow at least one of the first polymer fibers and the second polymer fibers to fill void space on the dual fiber mat.

8 . The method of claim 7 , wherein the step of exposing the dual fiber mat to solvent vapor to soften and flow at least one of the first polymer fibers and the second polymer fibers further comprises:
thermal annealing the dual fiber mat.

9 . The method of claim 1 , wherein the step of processing the dual fiber mat to form the composite membrane comprises:
compressing the dual fiber mat; and heating to anneal the dual fiber mat, and flowing at least one of the first polymer fibers and the second polymer fibers to fill void space on the dual fiber mat.

10 . The method of claim 1 , wherein the step of processing the dual fiber mat to form the composite membrane comprises crosslinking the charged polymer and the first uncharged polymer in the first polymer fibers of the dual fiber mat.

11 . The method of claim 1 , wherein the step of processing the dual fiber mat to form the composite membrane comprises crosslinking the second uncharged polymer in the second polymer fibers of the dual fiber mat formed.

12 . The method of claim 1 , wherein the composite membrane is a proton exchange membrane (PEM), or an anion exchange membrane (AEM).

13 . A membrane-electrode-assembly (MEA) for an electrochemical device, comprising at least one composite membrane that is fabricated by the method of claim 1 .

14 . A composite membrane, comprising:
a fiber network of first polymer fibers surrounded by a matrix formed from second polymer fibers or a fiber network of the second polymer fibers surrounded by a matrix formed from the first polymer fibers, wherein the first polymer fibers are formed from a first solution, and the first solution comprises a charged polymer and a first uncharged polymer having a repeat unit of a formula of:

 wherein each of X and Y is a non-hydroxyl group; and
the second polymer fibers are formed from a second solution, and the second solution comprises a second uncharged polymer.

15 . The composite membrane of claim 14 , wherein the polymer matrix is formed by:
softening and flowing the first polymer fibers of a dual fiber mat formed by the first polymer fibers and the second polymer fibers, to fill void space between the second polymer fibers in the dual fiber mat; or softening and flowing the second polymer fibers of the dual fiber mat formed by the first polymer fibers and the second polymer fibers, to fill void space between the first polymer fibers in the dual fiber mat.

16 . The composite membrane of claim 14 , wherein the charged polymer is selected from perfluorosulfonic acid (PFSA) polymer and perfluoro imide acid (PFIA) polymer.

17 . The composite membrane of claim 16 , wherein the charged polymer is selected from Nafion® and Aquivion®.

18 . The composite membrane of claim 14 , wherein each of X and Y is fluoride, and the first uncharged polymer is polyvinylidene difluoride (PVDF) or a copolymer of PVDF.

19 . The composite membrane of claim 14 , wherein the second uncharged polymer is polyvinylidene difluoride (PVDF) or polyphenylsulsulfone (PPSU).

20 . The composite membrane of claim 14 , wherein the dual fiber mat is formed by electrospinning, separately and simultaneously, the first solution and the second solution.

21 . The composite membrane of claim 20 , wherein the composite membrane is formed by processing the dual fiber mat, and the step of processing the dual fiber mat comprises:
compressing the dual fiber mat; and soften and flow at least one of the first polymer fibers and the second polymer fibers to fill void space on the dual fiber mat.

22 . A fuel cell comprising at least one composite membrane of claim 14 .

23 . A membrane-electrode-assembly (MEA) for an electrochemical device, comprising at least one composite membrane of claim 14 .

24 . A method of fabricating a composite membrane, comprising:
forming a first solution comprising a charged polymer and a first uncharged polymer having a repeat unit of a formula of

 wherein each of X and Y is a non-hydroxyl group;
forming a second solution comprising a second uncharged polymer;
co-axial electrospinning to form a core-shell fiber mat having core-shell fibers, wherein each of the core-shell fibers has a core and a shell, the shell is formed from the first solution, and the core is formed form the second solution; and
processing the core-shell fiber mat to form the composite membrane.

25 . The method of claim 24 , wherein the charged polymer is selected from perfluorosulfonic acid (PFSA) polymer and perfluoro imide acid (PFIA) polymer.

26 . The method of claim 25 , wherein the charged polymer is selected from Nafion® and Aquivion®.

27 . The method of claim 24 , wherein each of X and Y is fluoride, and the first uncharged polymer is polyvinylidene difluoride (PVDF) or a copolymer of PVDF.

28 . The method of claim 24 , wherein the second uncharged polymer is polyvinylidene difluoride (PVDF) or polyphenylsulsulfone (PPSU).

29 . The method of claim 24 , wherein the step of processing the core-shell fiber mat to form the composite membrane comprises:
compressing the core-shell fiber mat; and exposing the core-shell fiber mat to solvent vapor to soften and flow at least one of the cores and the shells of the core-shell fibers to fill void space on the core-shell fiber

Assignees

• Univ Vanderbilt

Inventors

• Pintauro Peter N
• Park Andrew
• Ballengee Jason

Classifications

• H01M8/1025

  having only carbon and oxygen, e.g. polyethers, sulfonated polyetheretherketones [S-PEEK], sulfonated polysaccharides, sulfonated celluloses or sulfonated polyesters · CPC title

• H01M8/1088

  Chemical modification, e.g. sulfonation · CPC title

• H01M8/1027

  having carbon, oxygen and other atoms, e.g. sulfonated polyethersulfones [S-PES] · CPC title

• D01D5/0038

  the fibre formed by solvent evaporation, i.e. dry electro-spinning · CPC title

• H01M8/103

  having nitrogen, e.g. sulfonated polybenzimidazoles [S-PBI], polybenzimidazoles with phosphoric acid, sulfonated polyamides [S-PA] or sulfonated polyphosphazenes [S-PPh] · CPC title