Search

US-12623212-B2 - Physically reinforced structured organic film (SOF) anion exchange membranes (AEMs)

US12623212B2US 12623212 B2US12623212 B2US 12623212B2US-12623212-B2

Abstract

A structured organic film (SOF) composite is disclosed, including a structured organic film (SOF), which may include a plurality of segments; a plurality of linkers, where at least one of the plurality of linkers connects at least one of the plurality of segments. The composite also includes a polymer additive incorporated into the SOF. The polymer additive is present in the SOF in a plurality of nanodomains, ranging in size from about 50 nm to about 1 micron. The polymer additive may include a polysulfone. The polysulfone can be poly(oxy-1,4-phenylenesulfonyl-1,4-phenylene). The polymer additive is present in an amount of from about 5 wt % to about 25 wt % based on a total weight of the SOF composite. The structured organic film (SOF) composite may include an ionic segment or ionic capping segment.

Inventors

  • Robert Claridge

Assignees

  • XEROX CORPORATION

Dates

Publication Date
20260512
Application Date
20230802

Claims (19)

  1. 1 . A structured organic film (SOF) composite, comprising: a structured organic film (SOF), comprising: a plurality of segments; a plurality of linkers, wherein at least one of the plurality of linkers connects at least one of the plurality of segments; and a polymer additive comprising poly(oxy-1,4-phenylenesulfonyl-1,4-phenylene) incorporated into the SOF.
  2. 2 . The structured organic film (SOF) composite of claim 1 , wherein the polymer additive is present in the SOF in a plurality of nanodomains.
  3. 3 . The structured organic film (SOF) composite of claim 2 , wherein a size of the nanodomains is from about 50 nm to about 1 micron.
  4. 4 . The structured organic film (SOF) composite of claim 1 , wherein the polymer additive further comprises a polyvinyl alcohol.
  5. 5 . The structured organic film (SOF) composite of claim 1 , wherein the polymer additive is present in an amount of from about 5 wt % to about 25 wt % based on a total weight of the SOF composite.
  6. 6 . The structured organic film (SOF) composite of claim 1 , further comprising an ionic segment.
  7. 7 . The structured organic film (SOF) composite of claim 1 , further comprising an ionic capping segment.
  8. 8 . The structured organic film (SOF) composite of claim 1 , wherein a thickness of the SOF is from about 250 nm to about 500 μm.
  9. 9 . The structured organic film (SOF) composite of claim 1 , wherein the structured organic film (SOF) has an ion exchange capacity (IEC) of from about 0.25 mEq/g to about 5.00 mEq/g.
  10. 10 . The structured organic film (SOF) composite of claim 1 , wherein the structured organic film (SOF) has an electrical conductivity of from about 15 mS/cm to about 50 mS/cm.
  11. 11 . An ion-exchange membrane, comprising the structured organic film (SOF) composite of claim 1 .
  12. 12 . The ion-exchange membrane of claim 11 , wherein the structured organic film (SOF) composite is free-standing.
  13. 13 . A structured organic film (SOF) composite, comprising: a first domain comprising a first composition; and a second domain comprising a second composition and incorporated into the first domain; and wherein: the first composition comprises a plurality of segments, and a plurality of linkers, wherein at least one of the plurality of linkers connects at least one of the plurality of segments; and the second composition comprises a polymer additive comprising poly(oxy-1,4-phenylenesulfonyl-1,4-phenylene).
  14. 14 . The structured organic film (SOF) composite of claim 13 , wherein a size of the second domain is from about 50 nm to about 1 micron.
  15. 15 . The structured organic film (SOF) composite of claim 13 , wherein at least one of the plurality of segments comprises:
  16. 16 . The structured organic film (SOF) composite of claim 13 , wherein at least one of the plurality of segments comprises a piperidinium-based quaternary ammonium compound, a pyridinium-based quaternary ammonium compound or a combination thereof.
  17. 17 . The structured organic film (SOF) composite of claim 13 , further comprising a plurality of capping segments.
  18. 18 . The structured organic film (SOF) composite of claim 13 , wherein the plurality of capping segments comprises benzyl tris(2-hydroxyethyl) ammonium (BTHEA), N-hydroxyethyl-1,2,4,5-tetramethylimidazolium (NEtTMIm), or a combination thereof.
  19. 19 . A structured organic film (SOF) composite, comprising: a plurality of segments; and a plurality of linkers, wherein at least one of the plurality of linkers connects at least one of the plurality of segment; wherein at least one or more of the plurality of segments comprises N,N,N′,N′-tetrakis-[(4-hydroxymethyl) phenyl]-biphenyl-4,4′-diamine (THM-TBD); and a polysulfone comprising poly(oxy-1,4-phenylenesulfonyl-1,4-phenylene) incorporated into the SOF.

Description

TECHNICAL FIELD The present teachings relate generally to ionic exchange membranes and, more particularly, to anionic exchange membranes having components integrated into the structure of the membranes providing physical reinforcement. BACKGROUND Ion-exchange membranes (IEM) can be used in many electrochemical devices including fuel cells, redox flow batteries, electrolyzers, reverse electrodialysis cells, and bioelectrochemical systems (BES) such as microbial fuel cells. IEMs are usually composed of hydrophobic substrates with immobilized ion-functionalized groups and mobile counter-ions. Depending on the type of ionic groups being transported, the IEMs can be anion exchange membranes (AEMs) or cation exchange membranes (CEMs). The commercial membranes available can contain imidazolium, alkylammonium or other non-disclosed quaternary ammonium salts. In addition to having exceptional alkaline stability, piperidinium based quaternary ammonium compounds exhibit ion exchange capacities (IEC) well within or exceeding the range of these commercial materials, up to ˜4.4 meq/g. This stability is advantageous for a viable commercial system when the ion exchange material is constantly subjected to alkaline conditions as part of an electrochemical cell, be it for a fuel cell or CO2 reduction. There are several commercial anion exchange membranes available today, including Fumasep® FAA3, A201, AEMION, Sustanion® and Orion TMI Durion™. Best case scenarios under operating conditions for Sustanion®, A201 and Fumasep® FAA3 are 2000 h, 1000 h and 1000 h respectively. AEMs that included piperidinium or pyridinium ionic groups have also shown high alkaline stability, with up to 99+% retention of IEC and conductivity after 600 h in 2M KOH at 80 C. Structured organic films can be used as alternate materials in ion exchange membranes. A significant drawback of existing structured organic film (SOF) materials is the brittle nature of resultant free standing film having SOF components. These films can be compromised when subjected to mechanical stresses which can cause cracks or defects that would be detrimental to electrochemical cell functionality. Cracks or holes in the films result in a shorting of an electrochemical cell due to water crossover. In addition, the brittle nature would make scale up of membrane materials difficult as a standard roll to roll process would not be viable. The brittle nature of the films can be due to the high aromaticity of some of the SOF building blocks, which are known to result in brittle materials. Therefore, it is desirable to fabricate ion exchange membranes synthesized from robust, SOF-based films that can be used in a variety of applications such as fuel cells, redox flow batteries, electrolyzers, reverse electrodialysis cells, and microbial fuel cells without exhibiting shortfalls in performance based on the development of the aforementioned defects. SUMMARY The following presents a simplified summary in order to provide a basic understanding of some aspects of one or more embodiments of the present teachings. This summary is not an extensive overview, nor is it intended to identify key or critical elements of the present teachings, nor to delineate the scope of the disclosure. Rather, its primary purpose is merely to present one or more concepts in simplified form as a prelude to the detailed description presented later. A structured organic film (SOF) composite is disclosed, including a structured organic film (SOF), which may include a plurality of segments: a plurality of linkers, where at least one of the plurality of linkers connects at least one of the plurality of segments. The composite also includes a polymer additive incorporated into the SOF. Implementations of the structured organic film (SOF) composite include where the polymer additive is present in the SOF in a plurality of nanodomains. A size of the nanodomains is from about 50 nm to about 1 micron. The polymer additive may include a polysulfone. The polysulfone can be poly(oxy-1,4-phenylenesulfonyl-1,4-phenylene). The polymer additive is present in an amount of from about 5 wt % to about 25 wt % based on a total weight of the SOF composite. The structured organic film (SOF) composite may include an ionic segment. The structured organic film (SOF) composite may include an ionic capping segment. A thickness of the SOF can be from about 250 nm to about 500 μm. The structured organic film (SOF) has an ion exchange capacity (IEC) of from about 0.25 meq/g to about 5.00 meq/g. The structured organic film (SOF) has an electrical conductivity of from about 15 ms/cm to about 50 ms/cm. An ion-exchange membrane, may include the structured organic film (SOF) composite. The structured organic film (SOF) composite can be free-standing. Another structured organic film (SOF) composite is disclosed, which can include a first domain having a first composition, and a second domain having a second composition and incorporated into the first