Reinforced ionomeric polyphenylene membranes and methods of use thereof

Abstract

Described herein are reinforced ionomeric polymer membranes comprising ionomeric linear, random, or statistical polymers and / or copolymers, and a porous scaffold reinforcement. Such reinforced ionomeric polymer membranes are used in electrochemical devices such as fuel cells, electrolyzers, hydrogen pumps, thermoelectrochemical hydrogen pumps, electrochemical hydrogen compressors, redox flow batteries, and other electrochemical devices, and have application in fuel cells, water electrolyzers, hydrogen compression, hydrogen decompression, water purification, and battery products. The reinforced ionomeric polymer membranes are prepared by both benchtop and automatic (i.e., machine, roll-to-roll) methods.

Description

REINFORCED IONOMERIC POLYPHENYLENE MEMBRANES AND METHODS OF USE THEREOF CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Application No. 63 / 614,336, filed on December 22, 2023, the disclosure of which is hereby incorporated by reference in its entirety. FIELD OF INVENTION

[0002] The present invention relates to a reinforced ionomeric polymer membrane for use in electrochemical devices such as fuel cells, electrolyzers, hydrogen pumps, thermoelectrochemical hydrogen pumps, electrochemical hydrogen compressors, redox flow batteries, and other electrochemical devices. BACKGROUND

[0003] Proton exchange membranes (PEM) are used in electrochemical devices as solid electrolytes. A membrane separating the cathode and anode transports ions formed at the catalyst layer of one electrode to the other electrode, enabling the device to function by either providing an electrical current (in the case of a fuel cell), producing gases (in the case of an electrolyzer), compressing a gas (in the case of an electrochemical hydrogen compressor or hydrogen pump), or decompressing a gas (in the case of a thermoelectrochemical hydrogen pump).

[0004] Fuel cells, solid polymer electrolyte electrolyzers, electrochemical compressors, hydrogen pumps, and thermoelectrochemical pumps must achieve high power densities and long lifetimes at low costs to achieve full commercialization and widespread integration. To do so, high performance and long-lasting PEMs are required. High performance PEMs can be characterized by high ion-conductivity, low electrical conductivity, low gas permeance (commonly referred to as gas crossover), high mechanical strength, and high dimensional stability. Long lifetimes, or general durability, can be characterized by resilience to accelerated stress test (AST) protocols such as relative humidity (RH) cycling in an operating fuel cell (in-situ). Recent developments in PEM fuel cells require membranes to be thinner (< 25 μm) and have higher ion exchange capacity (IEC) or lower equivalent weight (EW), due to the advantages obtained (reduced resistance, improved water transport, etc.). 2296-P9WO -1-

[0005] Some strategies aim to achieve these properties. For example, a composite PEM can be prepared by impregnating a porous material, often an expanded polytetrafluoroethylene (ePTFE) membrane with thickness less than 0.025 mm, with an ion-exchange material, or ionomeric polymer (ionomer), such as perfluorosulfonic acid (PFSA). This form of PEM is used in automotive fuel cell applications, enabling high ion conductance, mechanical strength, and stability at a low thickness. Typical examples of composite ion exchange membranes reinforced with porous materials are GORE- SELECT®, Nafion®XL, and Nafion®NC700.

[0006] However, PFSAs feature drawbacks which include: (1) environmental hazards associated with the use of (per)fluorinated compounds and their recovery and disposal, (2) high costs, both as a result of complex chemical processes and globally- restricted manufacturing; and (3) a limited operating temperature range due to the unsatisfactory thermo-mechanical properties at temperatures beyond 90 °C. A limiting issue of thin PFSA PEMs is fuel (in the case of a hydrogen fuel cell, hydrogen gas) crossover across the membrane during operation. Crossover results in both accelerated degradation of the membrane electrode assembly (MEA) components, and reduced fuel cell efficiency. Crossover in an electrochemical cell is often characterized by electrochemical techniques and can be described as a crossover current density. Crossover is often inversely related to membrane thickness, wherein a thinner membrane of the same chemical composition exhibits a higher gas crossover than a thicker derivative.

[0007] Hydrocarbon (HC) materials offer a range of advantages over conventional PFSA materials, such as reduced reactant (hydrogen) gas crossover, more flexible and lower cost chemistries, enhanced thermal and / or chemical stability, and reduced environmental concerns with their synthesis and utilization. Despite these benefits, HC materials generally experience severe mechanical stress under operating fuel cell conditions (e.g., frequent humidity and / or current density changes) as a result of high water uptake and dimensional swelling parameters. This leads to premature membrane failures in-situ, resulting in failure of the entire MEA. While a typical fuel cell stack contains multiple individual cells, each containing its own MEA, failure of any one MEA leads to performance degradation of the stack, increased stress on remaining cells, safety concerns over excessive hydrogen gas crossover, and potential failure of the entire stack. Similar mechanisms are noted for related electrochemical applications such as electrochemical 2296-P9WO -2-hydrogen compressors, hydrogen pumps, thermoelectrochemical hydrogen pumps, and water electrolyzers. These challenges hinder the commercial adoption of such materials.

[0008] Therefore, a need exists for a thin, sufficiently conductive PEM with low hydrogen gas crossover, and which exhibits mechanical durability and longevity to meet the demands of, and be used in, electrochemical devices. SUMMARY

[0009] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0010] In one aspect of the disclosure, provided herein is a reinforced ionomeric polymer membrane comprising an ionomeric polymer and a porous scaffold reinforcement, wherein the ionomeric polymer comprises a repeat unit (x) of Formula (I) having the structure: R1ER1D1Hwherein: R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl, each unsubstituted orwith 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO-X+; R1Gand R1Hare independently H, aryl, or heteroaryl, wherein said aryl and heteroaryl are each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO- X+;A1is arylene, heteroarylene, aralkylene, or heteroaralkylene, each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; 2296-P9WO -3-A2is absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; L1is an unsubstituted or substituted linking heteroatom, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; L2and L3are independently absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1- 6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and X+is H+, a cation, an alkali metal ion, or [N(RA)(RB)(RC)(RD)]+wherein RA, RB, RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

[0011] In another aspect of the disclosure, provided herein is a method for preparing the reinforced ionomeric polymer membrane, comprising impregnating the porous scaffold reinforcement with a liquid ionomeric polymer solution comprising the ionomeric polymer, and forming a membrane of the porous scaffold reinforcement and the ionomeric polymer.

[0012] In yet another aspect of the disclosure, provided herein is a fuel cell membrane-electrode assembly, an electrolyzer membrane-electrode assembly, and a hydrogen pump or thermoelectrochemical hydrogen pump membrane-electrode assembly.

[0013] In a further aspect of the disclosure, provided herein is a method of using the reinforced ionomeric polymer membrane in an electrochemical device such as a fuel cell, electrolyzer, hydrogen pump, thermoelectrochemical hydrogen pump, electrochemical hydrogen compressor, or redox flow battery.

[0014] In another aspect of the disclosure, provided herein is a reinforced ionomeric polymer membrane for use in an electrochemical device selected from a fuel cell, electrolyzer, hydrogen pump, thermoelectrochemical hydrogen pump, electrochemical hydrogen compressor, redox flow battery, or other electrochemical device. DESCRIPTION OF THE DRAWINGS

[0015] The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by 2296-P9WO -4-reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

[0016] FIGURE 1 is a simplified equivalent circuit. CPEdl the interfacial impedance at the electrode surface, Rbis the impedance of the membrane, and Cbis the bulk membrane capacitance.

[0017] FIGURE 2A is a graph of the comparison of tensile strain (elongation at break) of membranes prepared from 90%-sPP polymer #1 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0018] FIGURE 2B is a graph of the comparison of tensile strain of membranes prepared from 90%-sPP polymer #1 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0019] FIGURE 2C is a graph of the comparison of elastic modulus of membranes prepared from 90%-sPP polymer #1 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0020] FIGURE 2D is a graph of the comparison of toughness of membranes prepared from 90%-sPP polymer #1 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0021] FIGURE 3A is a graph of the comparison of tensile strain (elongation at break) of membranes prepared from 90%-sPP polymer #2 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0022] FIGURE 3B is a graph of the comparison of tensile strain of membranes prepared from 90%-sPP polymer #2 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0023] FIGURE 3C is a graph of the comparison of elastic modulus of membranes prepared from 90%-sPP polymer #2 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0024] FIGURE 3D is a graph of the comparison of toughness of membranes prepared from 90%-sPP polymer #2 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0025] FIGURE 4A is a graph of the comparison of tensile strain (elongation at break) of membranes prepared from 90%-sPP polymer #3 standalone prepared by 2296-P9WO -5-membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0026] FIGURE 4B is a graph of the comparison of tensile strain of membranes prepared from 90%-sPP polymer #3 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0027] FIGURE 4C is a graph of the comparison of elastic modulus of membranes prepared from 90%-sPP polymer #3 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0028] FIGURE 4D is a graph of the comparison of toughness of membranes prepared from 90%-sPP polymer #3 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0029] FIGURE 5A is a graph of the comparison of tensile strain (elongation at break) of membranes prepared from 90%-sPP polymer #4 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0030] FIGURE 5B is a graph of the comparison of tensile strain of membranes prepared from 90%-sPP polymer #4 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0031] FIGURE 5C is a graph of the comparison of elastic modulus of membranes prepared from 90%-sPP polymer #4 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0032] FIGURE 5D is a graph of the comparison of toughness of membranes prepared from 90%-sPP polymer #4 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0033] FIGURE 6A is a graph of the comparison of tensile strain (elongation at break) of membranes prepared from 90%-sPP polymer #3 standalone prepared by membrane casting process, or with a mechanical reinforcement (7 μm thickness ePTFE #1).

[0034] FIGURE 6B is a graph of the comparison of tensile strain of membranes prepared from 90%-sPP polymer #3 standalone prepared by membrane casting process, or with a mechanical reinforcement (7 μm thickness ePTFE #1). 2296-P9WO -6-

[0035] FIGURE 6C is a graph of the comparison of elastic modulus of membranes prepared from 90%-sPP polymer #3 standalone prepared by membrane casting process, or with a mechanical reinforcement (7 μm thickness ePTFE #1).

[0036] FIGURE 6D is a graph of the comparison of toughness of membranes prepared from 90%-sPP polymer #3 standalone prepared by membrane casting process, or with a mechanical reinforcement (7 μm thickness ePTFE #1).

[0037] FIGURE 7A is a graph of the comparison of ex-situ in-plane and through- plane conductivity properties of membranes prepared from 90%-sPP polymer #1 standalone prepared by membrane casting process, or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0038] FIGURE 7B is a graph of the comparison of ex-situ in-plane and through- plane conductivity properties of membranes prepared from polymer #3 standalone prepared by membrane casting process #1, or with a mechanical reinforcement (7 μm thickness ePTFE #1).

[0039] FIGURE 8A is a graph of the comparison of tensile strain (elongation at break) of membranes prepared from 100%-sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (5 μm thickness ePE #1), or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0040] FIGURE 8B is a graph of the comparison of tensile strain (elongation at break) of membranes prepared from 100%-sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (5 μm thickness ePE #1), or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0041] FIGURE 8C is a graph of the comparison of elastic modulus of membranes prepared from 100%-sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (5 μm thickness ePE #1), or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0042] FIGURE 8D is a graph of the comparison of toughness of membranes prepared from 100%-sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (5 μm thickness ePE #1), or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0043] FIGURE 8E is a graph of the comparison of in-plane and through-plane proton conductivity of membranes prepared from 100%-sPP polymer standalone prepared 2296-P9WO -7-by membrane casting process, with a mechanical reinforcement (5 μm thickness ePE #1), or with a mechanical reinforcement (4 μm thickness ePTFE #1).

[0044] FIGURE 9A is a graph of the comparison of water uptake (wt%) at RT and 80°C of membranes prepared from 100%-sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (5 μm thickness ePE #1), with a mechanical reinforcement (4 μm thickness ePTFE #1), or with a mechanical reinforcement (10 μm thickness e-spun PBI #1).

[0045] FIGURE 9B is a graph of the comparison of thickness swelling at RT and 80°C of membranes prepared from 100%-sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (5 μm thickness ePE #1), with a mechanical reinforcement (4 μm thickness ePTFE #1), or with a mechanical reinforcement (10 μm thickness e-spun PBI #1).

[0046] FIGURE 9C is a graph of the comparison of planar swelling in the machine direction (MD) and transverse direction (TD) at RT of membranes prepared from 100%- sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (5 μm thickness ePE #1), with a mechanical reinforcement (4 μm thickness ePTFE #1), or with a mechanical reinforcement (10 μm thickness e-spun PBI #1).

[0047] FIGURE 9D is a graph of the comparison of planar swelling in the machine direction (MD) and transverse direction (TD) at 80°C of membranes prepared from 100%- sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (5 μm thickness ePE #1), with a mechanical reinforcement (4 μm thickness ePTFE #1), or with a mechanical reinforcement (10 μm thickness e-spun PBI #1).

[0048] FIGURE 9E is a graph of the comparison of calculated volumetric swelling in the machine direction (MD) and transverse direction (TD) at 80°C of membranes prepared from 100%-sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (5 μm thickness ePE #1), with a mechanical reinforcement (4 μm thickness ePTFE #1), or with a mechanical reinforcement (10 μm thickness e-spun PBI #1).

[0049] FIGURE 10A is a graph of the comparison of water uptake (wt%) at RT and 80°C of membranes prepared from 90%-sPP polymer standalone prepared by membrane casting process, or with a mechanical reinforcement (15 μm thickness e-spun PBI #1).

[0050] FIGURE 10B is a graph of the comparison of thickness swelling at RT and 80°C of membranes prepared from 90%-sPP polymer standalone prepared by 2296-P9WO -8-membrane casting process, or with a mechanical reinforcement (15 μm thickness e-spun PBI #1).

[0051] FIGURE 10C is a graph of the comparison of planar swelling in the machine direction (MD) and transverse direction (TD) at RT of membranes prepared from 90%-sPP polymer standalone prepared by membrane casting process, or with a mechanical reinforcement (15 μm thickness e-spun PBI #1).

[0052] FIGURE 10D is a graph of the comparison of planar swelling in the machine direction (MD) and transverse direction (TD) at 80°C of membranes prepared from 90%- sPP polymer standalone prepared by membrane casting process, or with a mechanical reinforcement (15 μm thickness e-spun PBI #1).

[0053] FIGURE 10E is a graph of the comparison of calculated volumetric swelling in the machine direction (MD) and transverse direction (TD) at 80°C of membranes prepared from 90%-sPP polymer standalone prepared by membrane casting process, or with a mechanical reinforcement (15 μm thickness e-spun PBI #1).

[0054] FIGURE 10F is a graph of the comparison of in-plane and through-plane ex-situ proton conductivity of membranes prepared from 90%-sPP polymer standalone prepared by membrane casting process, or with a mechanical reinforcement (15 μm thickness e-spun PBI #1).

[0055] FIGURE 11A is a graph of the comparison of polarization and power density curves under 100 / 100 %RH (anode / cathode) of MEAs comprising reinforced membranes 11A, 11B, and 11C, versus two reference reinforced PFSA membranes (15 μm).

[0056] FIGURE 11B is a graph of the comparison of area-specific resistance (ASR) under 100 / 100 %RH (anode / cathode) of MEAs comprising reinforced membranes 11A, 11B, and 11C, versus two reference reinforced PFSA membranes (15 μm).

[0057] FIGURE 11C is a graph of the comparison of polarization and power density curves under 100 / 30 %RH (anode / cathode) of MEAs comprising reinforced membranes 11A, 11B, and 11C, versus two reference reinforced PFSA membranes (15 μm).

[0058] FIGURE 11D is a graph of the comparison of ASR under 100 / 30 %RH (anode / cathode) of MEAs comprising reinforced membranes 11A, 11B, and 11C, versus two reference reinforced PFSA membranes (15 μm). 2296-P9WO -9-

[0059] FIGURE 11E is a graph of the comparison of polarization and power density curves under 30 / 30 %RH (anode / cathode) of MEAs comprising reinforced membranes 11A, 11B, and 11C, versus two reference reinforced PFSA membranes (15 μm).

[0060] FIGURE 11F is a graph of the comparison of ASR under 30 / 30 %RH (anode / cathode) of MEAs comprising reinforced membranes 11A, 11B, and 11C, versus two reference reinforced PFSA membranes (15 μm).

[0061] FIGURE 12A is a graph of the comparison of water uptake (wt%) at RT and 80 °C, of membranes prepared from 90%-sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (43 μm thickness non-woven PPS #1), or with a mechanical reinforcement (5 μm thickness ePE #1).

[0062] FIGURE 12B is a graph of the comparison of thickness swelling at RT and 80 °C of membranes prepared from 90%-sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (43 μm thickness non-woven PPS #1), or with a mechanical reinforcement (5 μm thickness ePE #1).

[0063] FIGURE 12C is a graph of the comparison of planar swelling in the machine direction (MD, or x) and transverse direction (TD, or y) at RT of membranes prepared from 90%-sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (43 μm thickness non-woven PPS #1), or with a mechanical reinforcement (5 μm thickness ePE #1).

[0064] FIGURE 12D is a graph of the comparison of planar swelling in the machine direction (MD, or x) and transverse direction (TD, or y) at 80 °C of membranes prepared from 90%-sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (43 μm thickness non-woven PPS #1), or with a mechanical reinforcement (5 μm thickness ePE #1).

[0065] FIGURE 12E is a graph of the comparison of calculated volumetric swelling of membranes prepared from 90%-sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (43 μm thickness non-woven PPS #1), or with a mechanical reinforcement (5 μm thickness ePE #1).

[0066] FIGURE 12F is a graph of the comparison of calculated water uptake to volumetric swelling ratios of membranes prepared from 90%-sPP polymer standalone prepared by membrane casting process, with a mechanical reinforcement (43 μm thickness non-woven PPS #1), or with a mechanical reinforcement (5 μm thickness ePE #1). 2296-P9WO -10-

[0067] FIGURE 13A is a graphical depiction of a symmetrical reinforced membrane architecture wherein Layers 1 and 3 are ionomeric polymer surficial layers not containing a porous scaffold reinforcement. Layer 2 is a porous fibrous, stretched, or woven porous scaffold reinforcement fully embedded with ionomeric copolymer, wherein the scaffold is made of polysulfone (PSU), polyimide (PI), polyphenylene oxide (PPO), polyphenylene sulfoxide (PPSO), polyphenylene sulfide (PPS), polyphenylene sulfide sulfone (PPS / SO), polyparaphenylene (PPP), polyphenylduinoxaline (PPQ), polyarylketone (PK) polyethersulfone (PES), polyetherethersulfone (PEES), polyarylsulfone, polyarylethersulfone (PAS), polyphenylene sulfone (PPSU), polyphenylenesulfone (PPSO), polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketone-ketone (PEKK), polyetheretherketone-ketone (PEEKK) polyetherketoneetherketone-ketone (PEKEKK) polymers, polyphenylene sulfide (PPS), polyarylate, liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polypropylene (PP), polyethylene (PE), polyester, polyamide, polystyrene, polyvinyl chloride (PVC), polybenzoxazole (PBO), polybenzothiazole (PBT), polybenzimidazole (PBI), polyamide (PA), polyimide (PI), glass fiber, cellulose, aramid, polypara-phenylene terephthalamide (PPTA), or a combination thereof. FIGURE 13B is a graphical depiction of an asymmetrical reinforced membrane architecture wherein Layers 1 and 3 are ionomeric polymer surficial layers not containing a porous scaffold reinforcement. Layer 2 is a porous fibrous, stretched, or woven porous scaffold reinforcement fully embedded with ionomeric copolymer, wherein the scaffold is made of polysulfone (PSU), polyimide (PI), polyphenylene oxide (PPO), polyphenylene sulfoxide (PPSO), polyphenylene sulfide (PPS), polyphenylene sulfide sulfone (PPS / SO), polyparaphenylene (PPP), polyphenylduinoxaline (PPQ), polyarylketone (PK) polyethersulfone (PES), polyetherethersulfone (PEES), polyarylsulfone, polyarylethersulfone (PAS), polyphenylene sulfone (PPSU), polyphenylenesulfone (PPSO), polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketone-ketone (PEKK), polyetheretherketone-ketone (PEEKK) polyetherketoneetherketone-ketone (PEKEKK) polymers, polyphenylene sulfide (PPS), polyarylate, liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polypropylene (PP), polyethylene (PE), polyester, polyamide, polystyrene, polyvinyl chloride (PVC), polybenzoxazole (PBO), polybenzothiazole (PBT), polybenzimidazole (PBI), polyamide (PA), polyimide (PI), glass 2296-P9WO -11-fiber, cellulose, aramid, polypara-phenylene terephthalamide (PPTA), or a combination thereof.

[0068] FIGURE 13C is a graphical depiction of an asymmetrical reinforced membrane architecture wherein Layer 1 is an ionomeric polymer surficial layer not containing a porous scaffold reinforcement. Layer 2 is a porous fibrous, stretched, or woven porous scaffold reinforcement partially or fully embedded with ionomeric copolymer, wherein the scaffold is made of polysulfone (PSU), polyimide (PI), polyphenylene oxide (PPO), polyphenylene sulfoxide (PPSO), polyphenylene sulfide (PPS), polyphenylene sulfide sulfone (PPS / SO), polyparaphenylene (PPP), polyphenylduinoxaline (PPQ), polyarylketone (PK) polyethersulfone (PES), polyetherethersulfone (PEES), polyarylsulfone, polyarylethersulfone (PAS), polyphenylene sulfone (PPSU), polyphenylenesulfone (PPSO), polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketone-ketone (PEKK), polyetheretherketone-ketone (PEEKK) polyetherketoneetherketone-ketone (PEKEKK) polymers, polyphenylene sulfide (PPS), polyarylate, liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polypropylene (PP), polyethylene (PE), polyester, polyamide, polystyrene, polyvinyl chloride (PVC), polybenzoxazole (PBO), polybenzothiazole (PBT), polybenzimidazole (PBI), polyamide (PA), polyimide (PI), glass fiber, cellulose, aramid, polypara-phenylene terephthalamide (PPTA), or a combination thereof. FIGURE 13D is a graphical depiction of a symmetrical reinforced membrane architecture wherein Layers 1 and 3 are ionomeric polymer surficial layers not containing a porous scaffold reinforcement, comprising less of the total thickness of the membrane than FIGURE 13A. Layer 2 is a porous fibrous, stretched, or woven porous scaffold reinforcement fully embedded with ionomeric copolymer, wherein the scaffold is made of polysulfone (PSU), polyimide (PI), polyphenylene oxide (PPO), polyphenylene sulfoxide (PPSO), polyphenylene sulfide (PPS), polyphenylene sulfide sulfone (PPS / SO), polyparaphenylene (PPP), polyphenylduinoxaline (PPQ), polyarylketone (PK) polyethersulfone (PES), polyetherethersulfone (PEES), polyarylsulfone, polyarylethersulfone (PAS), polyphenylene sulfone (PPSU), polyphenylenesulfone (PPSO), polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketone-ketone (PEKK), polyetheretherketone-ketone (PEEKK) polyetherketoneetherketone-ketone (PEKEKK) polymers, polyphenylene sulfide (PPS), polyarylate, liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polypropylene (PP), polyethylene (PE), polyester, 2296-P9WO -12-polyamide, polystyrene, polyvinyl chloride (PVC), polybenzoxazole (PBO), polybenzothiazole (PBT), polybenzimidazole (PBI), polyamide (PA), polyimide (PI), glass fiber, cellulose, aramid, polypara-phenylene terephthalamide (PPTA), or a combination thereof, comprising more of the total thickness of the membrane than FIG.13A. DETAILED DESCRIPTION

[0069] To address the challenges associated with HC materials in proton exchange membrane applications, the present disclosure introduces reinforced (composite) hydrocarbon proton exchange membranes.

[0070] The present disclosure provides a reinforced hydrocarbon PEM comprising a porous scaffold reinforcement and one or more layers of sulfonated polyphenylene polymer (sPP). The reinforced hydrocarbon PEMs disclosed herein exhibit restricted in- plane swelling during membrane operation (for example, in a fuel cell), and reduced fuel crossover. Additionally, the membranes disclosed herein exhibit low electric resistance and high mechanical strength.

[0071] The composition, thickness, and porosity of the porous scaffold reinforcement can be adjusted to provide the desired combination of properties. For example, a fuel cell having a membrane with a relatively thick scaffold reinforcement may provide a low fuel crossover and high mechanical strength, but consequently exhibit relatively high electrical resistance. Definitions

[0072] The terminology used in the description of the invention herein is for the purpose of describing particular embodiments and is not intended to be limiting for the invention.

[0073] It is further appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, can also be provided in combination in a single embodiment. Conversely, various features of disclosure which are, for brevity, described in the context of a single embodiment, can also be provided separately or in any suitable subcombination.

[0074] The term “substituted” means that an atom or group of atoms formally replaces hydrogen as a “substituent” attached to another group. The term “substituted,” unless otherwise indicated, refers to any level of substitution, e.g., mono-, di-, tri-, tetra-, penta-, or higher substitution, where such substitution is permitted (e.g., results in a stable 2296-P9WO -13-compound). The substituents are independently selected, and substitution may be at any chemically accessible position. It is to be understood that substitution at a given atom is limited by valency.

[0075] When a group is unsubstituted, it can be referred to as the group name, for example alkyl or aryl.

[0076] Substituents of polymers of the disclosure are disclosed herein in groups or in ranges. It is specifically intended that the disclosure include each and every individual subcombination of the members of such groups and ranges. For example, the term “C1-6alkyl” is specifically intended to individually disclose (without limitation) methyl, ethyl, C3alkyl, C4alkyl, C5alkyl, and C6alkyl, and to include linear or branched geometric isomers when such geometric isomers are possible. For example, C4alkyl can be n-butyl, sec-butyl, isobutyl, or tert-butyl.

[0077] It is further appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, can also be provided in combination in a single embodiment. Conversely, various features of the disclosure which are, for brevity, described in the context of a single embodiment, can also be provided separately or in any suitable subcombination.

[0078] As used herein, the term “alkyl” refers to straight, branched, or cyclic hydrocarbon groups. In some embodiments, alkyl has 1 to 6 carbon atoms, 1 to 5 carbon atoms, 1 to 4 carbon atoms, 1 to 3 carbon atoms, 1 or 2 carbon atoms, or 1 carbon atom. Representative alkyl groups include methyl, ethyl, propyl (e.g., n-propyl, isopropyl, cyclopropyl), butyl (e.g., n-butyl, sec-butyl, isobutyl, tert-butyl, cyclobutyl), pentyl (e.g., n-pentyl, tert-pentyl, neopentyl, isopentyl, pentan-2-yl, pentan-3-yl, cyclopentyl), and hexyl (e.g., n-hexyl, geometric isomers, cyclohexyl) groups.

[0079] As used herein, the term “alkylene” refers to a linking alkyl group.

[0080] As used herein, the term “aryl” refers to an aromatic hydrocarbon group having 6 to 14 carbon atoms. Representative aryl groups include phenyl groups and naphthyl groups. In some embodiments, the term “aryl” includes monocyclic or polycyclic (e.g., having 2 or 3 fused rings) aromatic hydrocarbons such as, for example, phenyl, naphthyl, anthracenyl, phenanthrenyl, indanyl, and indenyl.

[0081] As used herein, the term “arylene” refers to a linking aryl group. For example, the term “phenylene” refers to a linking phenyl group. 2296-P9WO -14-

[0082] As used herein, the term “aralkyl” refers to an alkyl group as defined herein, with an aryl group as defined herein, substituted for one of the alkyl hydrogen atoms. A representative aralkyl group is a benzyl group.

[0083] As used herein, the term “aralkylene” refers to a linking aralkyl group.

[0084] As used herein, the term “heteroaryl” refers to a 5- to 10-membered aromatic monocyclic or bicyclic ring containing 1-4 heteroatoms selected from O, S, and N. Representative 5- or 6-membered aromatic monocyclic ring groups include pyridine, pyrimidine, pyridazine, furan, thiophene, thiazole, oxazole, and isooxazole. Representative 9- or 10-membered aromatic bicyclic ring groups include benzofuran, benzothiophene, indole, pyranopyrrole, benzopyran, quinoline, benzocyclohexyl, and naphthyridine.

[0085] As used herein, the term “heteroarylene” refers to a linking heteroaryl group.

[0086] As used herein, the term “heteroaralkyl” refers to an alkyl group as defined herein with a heteroaryl group as defined herein substituted for one of the alkyl hydrogen atoms. For example, a representative heteroaralkyl group is an alkylpyridyl group.

[0087] As used herein, the term “heteroaralkylene” refers to a linking heteroaralkyl group.

[0088] As used herein, the term “halogen” or “halo” refers to fluoro, chloro, bromo, and iodo groups. “Halogen” or “halo” can refer to the entire set of fluoro, chloro, bromo, and iodo groups, or to a subset of halogen atoms, e.g. fluoro, chloro, and bromo; chloro, bromo, and iodo; and any other combination or subcombination of halogen atoms.

[0089] As used herein, the term “heteroatomic” or “heteroatomic groups” refers to one or more heteroatoms, wherein the one or more heteroatoms is selected from N, O, and S.

[0090] As used herein, the term “copolymer” refers to a polymer that is the result of polymerization of two or more different monomeric units. The number and the nature of each monomeric unit can be separately controlled in a copolymer. The copolymer comprises at least one monomeric unit which is ionomeric, and at least one monomeric unit which is not ionomeric, or is uncharged. The ionomeric monomers in the copolymer can be the same or can be different. The uncharged monomers in the copolymer can be the same or can be different.

[0091] As used herein, the term “repeat unit” corresponds to the smallest monomeric unit or constitutional unit, the repetition of which constitutes a macromolecule 2296-P9WO -15-(or polymer or block). The monomeric unit of a polymer refers to a group of atoms in a monomer, comprising a part of the polymer chain, together with its pendant atoms or groups of atoms. The monomeric unit is a repeating unit within a chain. The monomeric unit can also refer to an end group on a polymer chain. For example, the monomeric unit of polyethylene glycol can be –CH2CH2O- corresponding to a repeating unit, or – CH2CH2OH corresponding to an end group. As used herein, the term “end group” refers to a repeating unit, or monomeric unit, with only one attachment to a polymer chain, located at the end of a polymer.

[0092] The repeat units can be disposed in a purely random, an alternating random, a regular alternating, a statistical, a regular block, or a random block configuration unless expressly stated to be otherwise.

[0093] As used herein, the term “random copolymer” is a copolymer having an irregular mixture of two or more monomeric units. The distribution of the monomeric units throughout the polymer can be a statistical distribution, or approach a statistical distribution, of the repeat units. In some embodiments, the distribution of one or more of the monomeric units is favored. A purely random configuration can, for example, be: x x y z x y y z y z z z... or y z x y z y z x x.... An alternating random configuration can be: x y x z y x y z y x z…, and a regular alternating configuration can be: x y z x y z x y z….

[0094] As used herein, the term “statistical copolymer” is a copolymer having a composition of monomeric units as determined by the mole percent of monomeric units used to generate the polymer. For example, in a statistical copolymer comprising 90% ionomeric monomer and 10% uncharged monomer, the resulting polymer is expected to consist of 90% ionomeric monomer units and 10% uncharged monomer units. A statistical polymer comprises an average composition ratio of x and y monomer units.

[0095] A regular block configuration (i.e., a block copolymer) has the following example configuration when comprising 3 different monomeric units (x, y, and z) for the block: …x x x y y y z z z x x x…, while a random block configuration has the following general example configuration of, for example: …x x x z z z x x x y y y y z z z x x x z z z z …., or for example, …x-x-x-y-y-y-y-x-x-x-y-y-y-x-x-x-x-y-y-y… A block copolymer comprises blocks of 3 or more of the same monomeric unit.

[0096] As used herein, the term “cationic” refers to a moiety that is positively charged, or ionizable to a positively charged moiety under chemical or acidic conditions 2296-P9WO -16-relative to the pKa of an atom. Examples of cationic moieties include, for example, ammonium, iminium, imidazolium, oxazolium, thiazolium groups, etc.

[0097] As used in the description of the invention and the appended claims, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0098] In the detailed description herein, references to “one embodiment”, “an embodiment”, “an example embodiment”, “one or more embodiments”, “some embodiments”, various embodiments”, etc., indicate that the embodiment or embodiments described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment or embodiments. In addition, when a particular feature, structure, or characteristic is described in connection with an embodiment or embodiments, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments. Thus, it will be appreciated that embodiments of the present disclosure may employ any combination of features described herein. All such combinations or sub-combinations of features are within the scope of the present disclosure.

[0099] As used herein, the term “about” can be understood to include values within 10% of the stated value. For example, a temperature of “about 40°C” means the temperature is 40 ± 4 °C. Otherwise stated, the temperature is 36°C – 44°C.

[0100] It is further intended that the compounds of the disclosure are stable. As used herein, “stable” refers to a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture.

[0101] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the present application and relevant art, and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 2296-P9WO -17-Membrane Ionomeric Polymers

[0102] In one aspect, the present disclosure provides a reinforced ionomeric polymer membrane comprising an ionomeric polymer and a porous scaffold reinforcement, wherein the ionomeric polymer comprises a repeat unit (x) of Formula (I).

[0103] In some embodiments, the present disclosure provides a reinforced ionomeric polymer membrane comprising an ionomeric polymer and a porous scaffold reinforcement, wherein the ionomeric polymer further comprises a repeat unit (y) of Formula (II).

[0104] In some embodiments, the present disclosure provides a reinforced ionomeric polymer membrane comprising an ionomeric copolymer and a porous scaffold reinforcement, wherein the ionomeric copolymer comprises a first repeat unit (x) of Formula (I) and a second repeat unit (y) of Formula (II).

[0105] In some embodiments disclosed herein, the repeat unit (x) of Formula (I) has the structure: R1ER1D1Hwherein: R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO-X+; R1Gand R1Hare independently H, aryl, or heteroaryl, wherein said aryl and heteroaryl are each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO- X+; A1is arylene, heteroarylene, aralkylene, or heteroaralkylene, each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; 2296-P9WO -18-A2is absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; L1is an unsubstituted or substituted linking heteroatom, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; L2and L3are independently absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1- 6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and X+is H+, a cation, an alkali metal ion, or [N(RA)(RB)(RC)(RD)]+wherein RA, RB, RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

[0106] In some embodiments disclosed herein, the repeat unit (x) of Formula (I) has the structure: R1ER1D1Hwherein: R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO-X+, and provided that at least two of R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl substituted with 1, 2, 3, 4, or 5 substituents independently selected from SO3-X+, PO32-2X+, and COO- X+; R1Gand R1Hare independently H, aryl, or heteroaryl, wherein said aryl and heteroaryl are each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO- X+; 2296-P9WO -19-A1is arylene, heteroarylene, aralkylene, or heteroaralkylene, each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; A2is absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; L1is an unsubstituted or substituted linking heteroatom, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; L2and L3are independently absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1- 6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and X+is H+, a cation, an alkali metal ion, or [N(RA)(RB)(RC)(RD)]+wherein RA, RB, RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

[0107] In some embodiments, the repeat unit (x) of Formula (I) is a repeat unit of Formula (I-A): R1ER1Dwherein:R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-X+2, and COO-X+; R3A, R3B, R3C, and R3Dare independently selected from H, halo, nitro, cyano, aryl, and heteroaryl; L1is an optionally substituted linking heteroatom, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and 2296-P9WO -20-heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; L2is absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted orwith 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and L2and L3are independently absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1- 6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and X+is H+, a cation, an alkali metal ion, or [N(RA)(RB)(RC)(RD)]+wherein RA, RB, RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

[0108] In some embodiments of Formula (I-A), R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-X+2, and COO-X+, and provided that at two of R1A, R1B, R1C, R1D, R1E, and R1Fareindependently aryl or heteroaryl substituted with 1, 2, 3, 4, or 5 substituents independently selected from SO3-X+, PO32-X+2, and COO-X+.

[0109] In some embodiments disclosed herein, the ionomeric polymer of the reinforced ionomeric polymer membrane further comprises a repeat unit (y) of Formula (II), wherein Formula (II) has the structure: R2E1Hwherein: R2A, R2B, R2C, R2D, R2E, and R2Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, and cyano; R1Gand R1Hare independently H, aryl, or heteroaryl, wherein said aryl and heteroaryl are each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents 2296-P9WO -21-independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO- X+; B1is arylene, heteroarylene, aralkylene, or heteroaralkylene, each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; B2is absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; L1is an unsubstituted or substituted linking heteroatom, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; L2and L3are independently absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and X+is H+, a cation, an alkali metal ion, or [N(RA)(RB)(RC)(RD)]+wherein RA, RB, RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

[0110] In some embodiments, the repeat unit (y) of Formula (II) is a repeat unit of Formula (II-A): R2ER wherein:R2A, R2B, R2C, R2D, R2E, and R2Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, and cyano; R4A, R4B, R4C, and R4Dare independently selected from H, halo, nitro, cyano, aryl, and heteroaryl; 2296-P9WO -22-L1is an optionally substituted linking heteroatom, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; L2is absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and L2and L3are independently absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1- 6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and X+is H+, a cation, an alkali metal ion, or [N(RA)(RB)(RC)(RD)]+wherein RA, RB, RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

[0111] In some embodiments, the ionomeric polymer has a structure of Formula (III): R1ER2BR1DR2Aywherein: R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO-X+; R2A, R2B, R2C, R2D, R2E, and R2Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, and cyano; R1Gand R1Hare independently H, aryl, or heteroaryl, wherein said aryl and heteroaryl are each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO- X+; 2296-P9WO -23-A1and B1are independently arylene, heteroarylene, aralkylene, or heteroaralkylene, each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; A2and B2are independently absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; L1is an unsubstituted or substituted linking heteroatom, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; L2and L3are independently absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1- 6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and X+is H+, a cation, an alkali metal ion, or [N(RA)(RB)(RC)(RD)]+wherein RA, RB, RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

[0112] In some embodiments of Formula (III), R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-X+2, and COO-X+, and provided that at least two of R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl substituted with 1, 2, 3, 4, or 5 substituents independently selected from SO3-X+, PO32-X+2, and COO-X+.

[0113] In some embodiments, the ionomeric polymer has a structure of Formula (IV): R3R42296-P9WO -24-(IV), wherein: R3, R4, R5, and R6are independently selected from H, SO3-X+, PO32-2X+, and COO-X+; R7, R8, R9, and R10are independently selected from H, C1-6alkyl, halo, nitro, and cyano; A1and B1are independently arylene, heteroarylene, aralkylene, or heteroaralkylene, each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; A2and B2are independently absent, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, or heteroaralkylene, are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; L1is independently an unsubstituted or substituted linking heteroatom, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; L2and L3are independently absent, arylene, heteroarylene, aralkylene, and heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and X+is H+, a cation, an alkali metal ion, or [N(RA)(RB)(RC)(RD)]+wherein RA, RB, RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

[0114] In some embodiments of Formula (IV), R3, R4, R5, and R6are independently selected from H and SO3-X+. In some embodiments of Formula (IV), R3, R4, R5, and R6are SO3-X+.

[0115] In some embodiments of Formula (IV), R7, R8, R9, and R10are H.

[0116] In some embodiments, A1is arylene and A2is absent. In some embodiments A1is phenylene and A2is absent.

[0117] In some embodiments, B1is arylene and B2is absent. In some embodiments B1is phenylene and B2is absent. 2296-P9WO -25-

[0118] In some embodiments, R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, and SO3-X+.

[0119] In some embodiments, R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, and provided that at least two of R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl substituted with 1, 2, 3, 4, or 5 SO3-X+.

[0120] In some embodiments, R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 SO3-X+.

[0121] In some embodiments, R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 SO3-X+, and provided that at least two of R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl substituted with 1, 2, 3, 4, or 5 SO3-X+.

[0122] In some embodiments, R1A, R1B, R1C, R1D, R1E, and R1Fare aryl, each independently unsubstituted or substituted with 1, 2, 3, 4, or 5 SO3-X+.

[0123] In some embodiments, R1A, R1B, R1C, R1D, R1E, and R1Fare aryl, each independently unsubstituted or substituted with 1, 2, 3, 4, or 5 SO3-X+, and provided that at least two of R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl substituted with 1, 2, 3, 4, or 5 SO3-X+.

[0124] In some embodiments, R1A, R1B, R1C, R1D, R1E, and R1Fare phenyl, each independently unsubstituted or substituted with 1, 2, 3, 4, or 5 SO3-X+.

[0125] In some embodiments, R1A, R1B, R1C, R1D, R1E, and R1Fare phenyl, each independently unsubstituted or substituted with 1, 2, 3, 4, or 5 SO3-X+, and provided that at least two of R1A, R1B, R1C, R1D, R1E, and R1Fare independently phenyl substituted with 1, 2, 3, 4, or 5 SO3-X+.

[0126] In some embodiments, R1A, R1B, R1C, R1D, R1E, and R1Fare phenyl, each are phenyl, eachthat at least two of R1A, R1B, R1C, R1D, R1E, and R1Fare independently phenyl substituted with 1 SO3-X+.

[0128] In some embodiments, R2A, R2B, R2C, R2D, R2E, and R2Fare independently aryl. In some embodiments, R2A, R2B, R2C, R2D, R2E, and R2Fare independently phenyl. 2296-P9WO -26-

[0129] In some embodiments, R3A, R3B, R3C, and R3Dare H.

[0130] In some embodiments, R4A, R4B, R4C, and R4Dare H.

[0131] In some embodiments, the repeat unit (x) of Formulae (I), (I-A), (III), and (IV) is selected from: SO+ + 3XSO3X , .(IV) is selected from: 2296-P9WO -27-SO+ 3XSO3X+ + , .(IV) is selected from: ,2296-P9WO -28-. -A), (III), and (IV) is selected from: m .(IV) is not: 2296-P9WO -29-SO X+ 3 .

[0136] In some phenylene, or C1-6alkyl-substituted phenylene, and L2and L3are independently absent or phenylene, wherein when present, each phenylene is unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl and halo.

[0137] In some embodiments, each L3, L2, and L1of –L3–L2–L1–, and each L3and L2, of –L3–L2–M1–, when present, are independently selected from: , , , ,2296-P9WO -30-, and

[0139] In some embodiments, L1is phenylene, and L2and L3are independently absent or phenylene.

[0140] In some embodiments, the L1of repeat unit (x) is the same or different from the L1of repeat unit (y). In some embodiments, the L2of repeat unit (x) is the same or different from the L2of repeat unit (y). In some embodiments, the L3of repeat unit (x) is the same or different from the L3of repeat unit (y).

[0141] In some embodiments, the ionomeric polymer further comprises a branching comonomer M1, wherein M1is selected from an unsubstituted or substituted linking atom, an arylene, heteroarylene, aralkylene, heteroaralkylene, and combinations thereof, wherein the linking atom, arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, or 3 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl.

[0142] In some embodiments, M1is bound through a covalent bond to at least 3 sulfonated polyphenylene repeat units, hydrophobic polyphenylene repeat units, or a 2296-P9WO -31-combination thereof. For example, for an M1bound to 3 repeat units, the combination can be M1bound through a covalent bond to 1 sulfonated polyphenylene repeat unit (x) of Formulae (I) or (I-A) and 2 polyphenylene repeat units (y) of Formulae (II) or (II-A), or the combination can be M1bound through a covalent bond to 2 sulfonated polyphenylene repeat units (x) of Formulae (I) or (I-A) and 1 polyphenylene repeat unit (y) of Formulae(II) or (II-A).

[0143] In some embodiments, M1is selected from the group consisting of: . of: R1ER1Dwherein P1and P2are independently selected from a repeat unit (x) of Formulae (I) and (I-A), and a repeat unit (y) of Formulae (II) and (II-A).

[0145] In some embodiments, the structure of Formula (V) further comprises a biphenyl.

[0146] In some embodiments, M1is phenyl, L2is p-phenyl, and L3is absent, to form a repeat unit (z) having Formula (VI): 2296-P9WO -32-

[0147] In some embodiments, the branched ionomeric polymer has a structure of Formula (VII): SO3H SO3HP1

[0148] The monomeric components of Formula (VII) are indicated below as “A,” “B,” and “C,” and result in the branched ionomeric polymer structure shown. The mole ratio of the components A, B, and C is about 100 mole percent A to B to Or, alternatively stated, the mole ratio of A to B to C is . 2296-P9WO -33-SO3H SO3HP1

[0149] In some embodiments of Formulae (V) and (VII), the mole ratio of z / (x+P1+P2) is less than 0.2.

[0150] In some embodiments, X+is H+, a cation, an alkali metal ion, or [N(RA)(RB)(RC)(RD)]+, wherein RA, RB, RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

[0151] In some embodiments, X+is H+, Na+, K+, HNEt3+, or Ce3+. In some embodiments, X+is H+. In some embodiments, X+is HNEt3+. In some embodiments, the ionomeric polymer comprises more than one different counterion X+.

[0152] In some embodiments, the mole percent of x is about 59% to about 99%, and the mole percent of y is about 41% to about 1%. In some embodiments, the mole percent of x is about 80% to about 99%, and the mole percent of y is about 20% to about 1%. In some embodiments, the mole percent of x is about 90%, and the mole percent of y is about 10%. 2296-P9WO -34-

[0153] In some embodiments, the ionomeric polymer is a random copolymer comprising a random distribution of x and y.

[0154] In some embodiments, the ionomeric polymer is a statistical copolymer comprising an average composition ratio of x and y.

[0155] In some embodiments, the ionomeric polymer is a block copolymer, wherein: x is an integer from 3 to 100, y is an integer from 3 to 100; and wherein a mole ratio of the first block to the second block ranges from 1:99 to 99:1. Membrane Porous Scaffold

[0156] In some embodiments, disclosed herein is a porous scaffold or porous scaffold layer. The porous scaffold layer of the membrane may be made from a wide range of components.

[0157] In some embodiments, the porous scaffold is a reinforcement comprising one or more stretched materials. In some embodiments, the one or more stretched materials are selected from expanded PE, expanded PTFE, expanded PP, expanded PMP, expanded polystyrene, expanded PVC, or a combination thereof. For example, a fluorine-containing polymer for the porous scaffold layer includes polytetrafluoroethylene (“PTFE”) or a copolymer of tetrafluoroethylene. U.S. Pat. No. 3,664,915 discloses uniaxially stretched film having at least 40% voids, herein incorporated by reference in its entirety. U.S. Pat. No. 3,953,566, 3,962,153 and 4,187,390 disclose porous PTFE films having at least 70% voids, herein incorporated by reference in their entirety. Pore size in the above films is typically at least for TEFLON® sheeting, including TEFLON® PFA and TEFLON® FEP, provided the molecular weight is sufficient to form a film. An “expanded” polymer as described herein is a polymer that has been heated or otherwise stretched to a larger area or volume of the polymer.

[0158] In some embodiments, the porous scaffold layer of the present invention can made from a hydrocarbon, such as a polyolefin, preferably having a melting point of about 220° C. The polyolefins particularly useful in making membranes for fuel cells include polyethylene, polypropylene, polybutylene, copolymers of those materials, and the like. The porous scaffold layer can be CELGARD®, MILLIPORE® or TYVEK®. Polyethylene can be used, and can be high, medium, or low density. 2296-P9WO -35-

[0159] In some embodiments, the porous scaffold of the present invention is a porous mat of nanofibres, wherein the nanofibres are composed of a non-ionically conducting heterocyclic-based polymer, the heterocyclic-based polymer comprising basic functional groups and being soluble in organic solvent. Heterocyclic polymers, preferably basic heterocyclic polymers, include polybenzimidazoles, poly(pyridine), poly(pyrimidine), polybenzthiazoles, polyoxadiazoles, polyquinolines, polyquinoxalines, polythiadiazoles, polytriazoles, polyoxazoles and polythiazoles and derivatives thereof. Suitably, the polymer is a functionalized polyazole or a zwitterionic polyazole, such as a polybenzimidazole, polytriazole, polythiazole, polydithiazole, and their derivatives. In some embodiments, the nanofibres are composed of polybenzimidazole. In some embodiments, the porous scaffold reinforcement comprises a plurality of nanofibers, wherein the plurality of nanofibers is from about 1 μm to about 50 μm in length.

[0160] In some embodiments, the plurality of nanofibers comprises a non-ionically conducting heterocyclic-based polymer, wherein the heterocyclic-based polymer is soluble in one or more organic solvent. In such embodiments, the organic solvent is selected from DMF, DMAc, NMP, THF, DCM, and combinations thereof. In some embodiments, the organic solvent is selected from DMF, DMAc, NMP, and combinations thereof.

[0161] In some embodiments, the plurality of nanofibers comprises a non-ionically conducting heterocyclic-based polymer.

[0162] In some embodiments, the plurality of nanofibers comprises a non-ionically conducting aryl-based polymer, heteroaryl-based polymer, or combinations thereof, and wherein the aryl-based polymer, heteroaryl-based polymer, or combinations thereof are independently unsubstituted or substituted with alkyl groups, heteroatomic groups, or combinations thereof.

[0163] In some embodiments, the plurality of nanofibers comprises one or more polymer building blocks selected from the group consisting of: polysulfone (PSU), polyimide (PI), polyphenylene oxide (PPO), polyphenylene sulfoxide (PPSO), polyphenylene sulfide (PPS), polyphenylene sulfide sulfone (PPS / SO), polyparaphenylene (PPP), polyphenylduinoxaline (PPQ), polyarylketone (PK) polyethersulfone (PES), polyetherethersulfone (PEES), polyarylsulfone, polyarylethersulfone (PAS), polyphenylene sulfone (PPSU), polyphenylenesulfone (PPSO), polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketone-ketone (PEKK), polyetheretherketone- ketone (PEEKK) polyetherketoneetherketone-ketone (PEKEKK) polymers, 2296-P9WO -36-polyphenylene sulfide (PPS), polyarylate, liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polypropylene (PP), polyethylene (PE), polyester, polyamide, polystyrene, polyvinyl chloride (PVC), polybenzoxazole (PBO), polybenzothiazole (PBT), polybenzimidazole (PBI), polyamide (PA), polyimide (PI), glass fiber, cellulose, aramid, polypara-phenylene terephthalamide (PPTA), and combinations thereof.

[0164] In some embodiments, the plurality of nanofibers are woven, stretched, drawn, made by electrospinning, wet-laid, or dry-laid, into a scaffold, sheet, or mat.

[0165] In some embodiments, the porous scaffold of the invention is a porous membrane made from poly(aryl ether ketone) (PAEK). Poly(aryl ether ketone)s represent a class of semi-crystalline engineering thermal plastics with outstanding thermal properties and chemical resistance. One representative polymer in this class is poly(ether ether ketone), PEEK, which has a continuous service temperature of approximately 250° C. Porous PEEK membranes are prepared from PEEK / polyimide blends by selective chemical decomposition and subsequent removal of the polyimide phase.

[0166] In some embodiments, the porous scaffold reinforcement is a porous membrane made from polyolefin (polyethylene, polypropylene, polybutylene, polymethylpentene), polystyrene, poly(tetrafluoroethylene), liquid crystal polymer (LCP), polysulfone, polyphenylene sulfone, polyphenylene sulfide, PEEK, PBI, PI, poly(aryl ether ketone) (PAEK), or polyacrylonitrile (PAN).

[0167] In some embodiments, the porous scaffold reinforcement comprises one or more electrospun materials. In some embodiments, the one or more electrospun materials are selected from electrospun PBI, electrospun PI, electrospun PEEK, electrospun PPS, electrospun PPSU, electrospun polyamide, or a combination thereof.

[0168] In some embodiments, the porous scaffold reinforcement comprises one or more woven materials. The porous support can be made from fibers of the polymers woven using various weaves such as the plain weave, basket weave, leno weave, or other weaves. In some embodiments, the one or more woven materials are selected from woven PEEK, woven PAEK, woven PPS, woven polyarylate or liquid crystal polymer (LCP), woven PTFE, woven PP, woven PE, woven polyester, woven polyamide, or a combination thereof.

[0169] In some embodiments, the porous scaffold reinforcement is a fabric which is woven or non-woven and: (a) provides mechanical / chemical anchoring sites whereby the s-PP ion exchange polymer can be firmly bonded / adhered; (b) provides a support 2296-P9WO -37-preventing the ion exchange membrane from being ruptured or damaged; and (c) by virtue of its thinness and high porosity, does not greatly reduce the effective cross section of the membrane for ionic conduction.

[0170] In this way, the reinforcement can be used to inexpensively reinforce thin s-PP membranes without negatively impacting the ionic conductivity of the membranes. The reinforcement can be a continuous sheet or may be a fabric, woven using various weaves, such as a plain weave, basket weave, leno weave, or others. Relatively open weaves are preferred because the electric resistance is lower. The fibers used in the scaffold fabrics may be monofilaments or multifilament yarns. They may be of ordinary round cross sections or may have specialized cross sections. Oblong or rectangular cross sections, if suitably oriented to the membrane, provide additional reinforcement with a thinner overall membrane.

[0171] , a porosity of from about 50 to 95%, and a thickness of from about , to obtain low fuel crossover, low membrane resistance, and high mechanical strength. Particularly preferred is about 70 to 90%, and a thickness of about relative to the entire volume of the porous material, and it is usually measured by a density method.

[0172] The porous reinforcement may be a non-continuous or a continuous sheet, or may be a fabric, woven using various weaves, such as the plain weave, basket weave, leno weave, or others. Non-continuous layers or relatively open weaves are preferred because the electric resistance is lower.

[0173] In some embodiments, the porous scaffold reinforcement comprises one or more non-woven materials. In some embodiments, the non-woven materials may be wet- laid or dry-laid materials. In some embodiments, the one or more wet laid materials are selected from wet-laid polyphenylene sulfide (PPS), wet-laid polybenzimidazole (PBI), wet-laid polyimide, wet-laid polyester, wet-laid glass fiber, wet-laid cellulose, or a combination thereof. In some embodiments, the one or more dry-laid materials are selected from dry-laid aramid, dry-laid polyethylene, dry-laid polypropylene, dry-laid polyester, or a combination thereof.

[0174] In some embodiments, the porous scaffold reinforcement has a pore diameter ranging from about 0.05 to about 10 . 2296-P9WO -38-

[0175] In some embodiments, the porous scaffold reinforcement has a porosity range from about 40% to about 90%.

[0176] In some embodiments, the porous scaffold reinforcement has a thickness of less than about 100 μm.

[0177] In some embodiments, the reinforced ionomeric polymer membrane has a thickness of about 10 μm to about 200 μm.

[0178] In some embodiments, the reinforced ionomeric polymer membrane has a thickness of less than about 100 μm.

[0179] In some embodiments, the reinforced ionomeric polymer membrane has a thickness of less than about 50 μm.

[0180] In some embodiments, the reinforced ionomeric polymer membrane has a thickness of less than about 20 μm.

[0181] In some embodiments, the reinforced ionomeric polymer membrane has a thickness, and the porous scaffold reinforcement comprises at least about 20% of the thickness of the reinforced ionomeric polymer membrane.

[0182] In some embodiments, the ionomeric polymer membrane has a thickness, and the porous scaffold reinforcement is distributed through at least about 50% of the thickness of the ionomeric polymer membrane.

[0183] In some embodiments, the ionomeric polymer membrane has a thickness, and the porous scaffold reinforcement is distributed through at least about 70% of the thickness of the ionomeric polymer membrane.

[0184] In some embodiments, the weight ratio of the ionomeric polymer to the porous scaffold reinforcement is greater than about 70:30.

[0185] In some embodiments, the weight ratio of the ionomeric polymer to the porous scaffold reinforcement is greater than about 90:10.

[0186] In some embodiments, an in-plane (x, y direction) swelling upon hydration is less than about 10%.

[0187] In some embodiments of the present disclosure, the porous scaffold substrate reinforcement material comprises a lyotropic liquid crystalline polymer, such as a polybenzazole (PBZ) or polyaramid (PAR or Kevlar R) polymer. Preferred polybenzazole polymers include polybenzoxazole (PBO), polybenzothiazole (PBT), and polybenzimidazole (PBI) polymers. 2296-P9WO -39-

[0188] Preferred polyaramid polymers include polypara-phenylene terephthalamide (PPTA) polymers. In other preferred embodiments, the polymer substrate of the PEM comprises a thermoplastic or thermoset aromatic polymer. Preferred aromatic polymers include: polysulfone (PSU), polyimide (PI), polyphenylene oxide (PPO), polyphenylene sulfoxide (PPSO), polyphenylene sulfide (PPS), polyphenylene sulfide sulfone (PPS / SO), polyparaphenylene (PPP), polyphenylduinoxaline (PPQ), polyarylketone (PK) and polyetherketone (PEK) polymers.

[0189] Preferred polysulfone polymers include polyethersulfone (PES), polyetherethersulfone (PEES), polyarylsulfone, polyarylethersulfone (PAS), polyphenylene sulfone (PPSU) and polyphenylenesulfone (PPSO) polymers. Preferred polyimide polymers include the polyetherimide polymers as well as fluorinated polyimides. Preferred polyetherketone polymers include polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketone-ketone (PEKK), polyetheretherketone-ketone (PEEKK) and polyetherketoneetherketone-ketone (PEKEKK) polymers

[0190] Preferred porous scaffold reinforcements possess exceptional mechanical properties (e.g., much greater than about 2500 psi tensile strength, much less than about 100% elongation to break), dimensional stability, barrier properties (to methanol, water vapor, oxygen, and hydrogen) even at elevated temperatures and pressures, and exceptional gauge uniformity (+ / - 0.2 mils preferable).

[0191] In some embodiments, the porous scaffold reinforcement has a pore size range of 10 Å to 2000 Å, or preferably 500 Å to 1000 Å. In some embodiments, the porous scaffold reinforcement has a porosity range of from about 40% to about 90%.

[0192] Preferred porous scaffold reinforcements are easily synthesized from commercially-available, low-cost starting materials, into thin, substantially defect free polymeric films which have high strength even at low thickness (preferably less than about1 mm), outstanding crease / crack resistance, and high tear strength. Preferred polymer substrates are substantially chemically resistant to acids, free radicals, and solvents (i.e., methanol), and are thermally and hydrolytically stable from temperatures of about 50° C to about 300° C. Preferred polymer substrates possess exceptional mechanical properties (much greater than about 2500 psi tensile, much less than about 100% elongation to break), dimensional stability, barrier properties (to methanol, water vapor, oxygen and hydrogen) even at elevated temperatures and pressures, and exceptional gauge uniformity (+ / -0.2 mm 2296-P9WO -40-preferable). In preferred embodiments, the polymer substrates are thermally and hydrolytically stable to temperatures of at least about 100° C.

[0193] Preferred polymer substrates have a pore size range of about 10 Å to about 20,000 Å more preferably about 10 Å to about 2000 Å, or between about 500 Å A to about 1000 Å, and have a porosity range from about 40% to 90%. Surface Treatment of Porous Scaffold Reinforcement

[0194] The surface energy of the porous scaffold may be appropriately varied to facilitate adhesion / lamination with the s-PP ion exchange layer. Various methods may be employed to vary the surface energy of the porous scaffold. For instance, an inorganic hydrophilic nature-imparting agent is incorporated during the formation of the porous scaffold material to impart a hydrophilic nature to the porous scaffold reinforcement. Examples of such inorganic hydrophilic nature-imparting agents include oxides, hydroxides, nitrides and carbides of e.g. titanium, zirconium, niobium, tantalum, vanadium, manganese, molybdenum and tin, as well as silicon carbide, barium titanate and barium sulfate. In another embodiment, the porous scaffold reinforcement could be plasma treated to alter surface energy, thereby altering the interaction of the porous scaffold reinforcement with the polymer in which it is embedded to form the composite membrane. In some embodiments, the porous scaffold reinforcement is plasma treated prior to incorporation into the reinforced ionomeric polymer membrane.

[0195] In some embodiments, the porous scaffold reinforcement comprises one layer in the reinforced ionomeric polymer membrane. In some embodiments, the porous scaffold reinforcement comprises two layers in the reinforced ionomeric polymer membrane. In some embodiments, the porous scaffold reinforcement comprises more than two layers in the reinforced ionomeric polymer membrane.

[0196] In some embodiments, the ionomeric polymer comprises one layer in the reinforced ionomeric polymer membrane. In some embodiments, the ionomeric polymer comprises two layers in the reinforced ionomeric polymer membrane. In some embodiments, the ionomeric polymer comprises more than two layers in the reinforced ionomeric polymer membrane.

[0197] In some embodiments, the porous scaffold reinforcement is impregnated with the ionomeric polymer. In some embodiments, the porous scaffold reinforcement includes a first face and a second face (such as Layer 2 of FIGS. 13A, 13B, and 13D), wherein the first face of the porous scaffold reinforcement is impregnated with a first liquid 2296-P9WO -41-ionomeric polymer solution of the ionomeric polymer (resulting in Layer 1 in FIGS.13A, 13B, and 13D), and where the second face of the porous scaffold reinforcement is impregnated with a second liquid ionomeric polymer solution of the ionomeric polymer (resulting in Layer 3 in FIGS. 13A, 13B, and 13D), and where the first liquid ionomeric polymer solution of the ionomeric polymer is the same or different from the second liquid ionomeric polymer solution of the ionomeric polymer.

[0198] In some embodiments, the porous scaffold reinforcement is heat treated, pressure treated, or a combination thereof, prior to incorporation into the reinforced ionomeric polymer membrane. Placement of Porous Scaffold Reinforcement

[0199] The porous scaffold reinforcement can be fully or partially embedded within the membrane, specifically fully or partially embedded within the ionomeric polymer. The placement of the reinforcement layer within the reinforced membrane is versatile, allowing for positioning anywhere within the thickness of the polymer. This includes the reinforcement being situated relatively in the middle (as shown, for example, in FIGS.13A and 13D); the reinforcement being situated closer to one face (as shown in FIG. 13B), which can be either the top face or the bottom face, and wherein the reinforcement is situated either slightly toward one face, or significantly toward one face; or the reinforcement partially or fully extending beyond one face (either the top or bottom face) (as shown in FIG. 13C) of the ionomeric polymer. A preferred embodiment involves placement of the reinforcement scaffold strategically positioned in the central region of the membrane, as in FIGS.13A and 13D. However, depending on the manufacturing technique and desired outcome, the reinforcement may preferentially be biased toward one face of the polymer as in FIG. 13B. During operation, in instances where the porous scaffold is partially embedded in the membrane or situated closed to one face of the membrane, the porous scaffold layer preferably faces the electrode which subjects the membrane to a higher mechanical, chemical, and / or thermal stress (e.g., the cathode of a hydrogen fuel cell). Methods of Making Porous Scaffold Reinforcement

[0200] In another aspect, disclosed herein is a method for preparing the reinforced ionomeric polymer membrane as described herein, the method including impregnating the porous scaffold reinforcement with a liquid ionomeric polymer solution comprising the 2296-P9WO -42-ionomeric polymer, and forming a composite membrane of the porous scaffold reinforcement and the ionomeric polymer.

[0201] In some embodiments, the liquid solution comprising the ionomeric polymer further comprises a plurality of particulates or nanofibers, wherein the particulates or nanofibers have a length of about 1 μm to about 50 μm.

[0202] In some embodiments, the liquid ionomeric polymer solution is a first liquid solution comprising a first ionomeric polymer, and the method further includes impregnating the porous scaffold reinforcement with a second liquid solution comprising a second ionomeric polymer, and where the first liquid solution and second liquid solution are the same or are different.

[0203] In some embodiments, the liquid ionomeric polymer solution comprises the ionomeric polymer of Formulae (I), (I-A), (II), (II-A), (III), or (IV), and one or more solvent, wherein the one or more solvent is selected from water, an organic alcohol, and mixtures thereof. Examples of organic alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, and the like. For example, the one or more solvent of the liquid ionomeric polymer solution is 9:1 isopropanol:water.

[0204] In some embodiments, the porous scaffold reinforcement includes a first face and a second face, and impregnating the porous scaffold reinforcement includes impregnating the first face of the porous scaffold reinforcement with a first liquid polymer solution of the ionomeric polymer, and impregnating the second face of the porous scaffold reinforcement with a second liquid polymer solution of the ionomeric polymer, where the first liquid polymer solution is the same or different from the second liquid polymer solution.

[0205] In some embodiments, the method further includes forming the porous scaffold reinforcement from a plurality of nanofibers.

[0206] In some embodiments, forming the porous scaffold reinforcement comprises drawing, stretching, electrospinning, wet-laying, dry-laying, or weaving the plurality of nanofibers into a scaffold, sheet, or mat.

[0207] In some embodiments, the method further includes forming the porous scaffold reinforcement from a woven material. The porous support could be made from fibers of the polymers woven using various weaves such as the plain weave, basket weave, leno weave, or others. In some embodiments, the one or more woven materials are selected from woven PEEK, woven PAEK, woven PPS, woven polyarylate or liquid crystal polymer 2296-P9WO -43-(LCP), woven PTFE, woven PP, woven PE, woven polyester, woven polyamide, or a combination thereof.

[0208] In some embodiments, the method further includes forming the porous scaffold reinforcement from one or more stretched material. In some embodiments, the one or more stretched materials are selected from expanded PE, expanded PTFE, expanded PP, expanded PMP, expanded polystyrene, expanded PVC, or a combination thereof.

[0209] In some embodiments, the method further includes forming the porous scaffold reinforcement from one or more electrospun materials. In some embodiments, the one or more electrospun materials are selected from electrospun PBI, electrospun PI, electrospun PEEK, electrospun PPS, electrospun PPSU, electrospun polyamide, or a combination thereof.

[0210] In some embodiments, the method further includes forming the porous scaffold reinforcement from one or more wet-laid materials. In some embodiments, the one or more wet laid materials are selected from wet-laid polyphenylene sulfide (PPS), wet- laid polybenzimidazole (PBI), wet-laid polyimide, wet-laid polyester, wet-laid glass fiber, wet-laid cellulose, or a combination thereof.

[0211] In some embodiments, the method further includes forming the porous scaffold reinforcement from one or more dry laid materials. In some embodiments, the one or more dry-laid materials are selected from dry-laid aramid, dry-laid polyethylene, dry- laid polypropylene, dry-laid polyester, or a combination thereof.

[0212] In some embodiments, the method further includes heat treating the porous scaffold reinforcement before impregnation; pressure treating the porous scaffold reinforcement before impregnation; or a combination thereof.

[0213] In some embodiments, the method further includes plasma treating the porous scaffold reinforcement before impregnation.

[0214] The porous scaffold / mat may be impregnated with the ionomeric polymer by the following process: A layer of ionomeric polymer (in solution / dispersion) is deposited or cast onto a carrier material. While the layer of ionomeric polymer is still wet and / or liquid, the porous scaffold / mat is laid into the liquid layer and the ionomeric polymer impregnates one face of the porous mat. Ionomeric polymer is further applied to a second face of the porous mat, impregnating the porous mat from the second face. All (about 100%), substantially all (about 98 to about 99%), most (more than about 85%), or some (more than about 50%) of 2296-P9WO -44-the porous scaffold reinforcement is impregnated with the ionomeric polymer solution. The impregnated porous mat is dried and suitably annealed to form the reinforced ionomeric polymer membrane. Alternatively, an ionomeric polymer solution is deposited or cast onto a carrier material or substrate. While the ionomeric polymer solution is still wet and / or liquid, the porous scaffold / mat is laid into the ionomeric polymer and the ionomeric polymer impregnates the entirety (all or substantially all) of the porous mat and may further exit the second face.

[0215] The solution / dispersion of ionomeric polymer may comprise additional components, for example short nanofibers, e.g., from 1 to 50 μm.

[0216] Alternative methods for impregnating the porous mat with ionomeric polymer will be known to those skilled in the art.

[0217] In the final reinforced ionomeric polymer membrane, the weight ratio of ionomeric polymer:scaffold is greater than 70:30, and preferably greater than 90:10. In some embodiments, the ionomeric polymer:scaffold ratio is less than 98:2.

[0218] The thickness of the porous scaffold in the reinforced ionomeric polymer membrane is suitably distributed across at least 50%, at least 60%, and most suitably at least 70%, of the thickness of the total reinforced ionomeric polymer membrane. The porous mat extends across the thickness of the membrane, such that the thickness of the reinforced ionomeric polymer membrane and the thickness of the porous mat are essentially equal; however, practically, the thickness of the reinforced ionomeric polymer membrane is slightly thicker than that of the porous mat, such that the thickness of the porous mat is at most 99%, or is about 95% of the thickness of the reinforced ionomeric polymer membrane.

[0219] Having the porous scaffold distributed across at least 80% of the thickness of the reinforced ionomeric polymer membrane enhances the stabilization of the final reinforced ionomeric polymer membrane.

[0220] A reinforced ionomeric polymer membrane of the disclosure may comprise more than one porous scaffold, e.g., two porous scaffolds together distributed across at least 50% of the thickness of the reinforced ionomeric polymer membrane.

[0221] The structure of the reinforced ionomeric polymer membrane comprising a porous scaffold and ionomeric polymer may contain sufficient molecular free volume to afford disproportionate water uptake of the reinforced ionomeric polymer membrane in comparison to its volumetric swelling, wherein the latter is restricted. 2296-P9WO -45-Applications of Porous Scaffold Reinforcement

[0222] In yet another aspect, disclosed herein is a fuel cell membrane-electrode assembly, including a) a hydrogen electrode to which hydrogen gas is supplied, b) an oxygen electrode to which an oxidizer gas is supplied, and c) a reinforced ionomeric polymer membrane located between the hydrogen and oxygen electrodes, the reinforced ionomeric polymer membrane being as described herein.

[0223] In yet another aspect, disclosed herein is an electrolyzer membrane- electrode assembly, including a) a hydrogen evolution electrode configured for the evolution of hydrogen gas, b) an oxygen evolution electrode configured for the evolution of oxygen gas, and c) a reinforced ionomeric polymer membrane located between the hydrogen and oxygen evolution electrodes, the reinforced ionomeric polymer membrane being as disclosed herein.

[0224] In another aspect, disclosed herein is a hydrogen pump or thermoelectrochemical hydrogen pump membrane-electrode assembly, including a) a hydrogen electrode configured to receive and split hydrogen gas, b) a secondary hydrogen electrode to which protons are transmitted and the hydrogen is reformed, and c) a reinforced ionomeric polymer membrane located between the hydrogen electrode and the secondary hydrogen electrode, the reinforced ionomeric polymer membrane being as disclosed herein.

[0225] In some embodiments is provided a method of using the reinforced ionomeric polymer membrane as described herein in an electrochemical device such as a fuel cell, electrolyzer, hydrogen pump, thermoelectrochemical hydrogen pump, electrochemical hydrogen compressor, or redox flow battery.

[0226] In some embodiments, the reinforced ionomeric polymer membrane as described herein is provided for use in an electrochemical device selected such as a fuel cell, electrolyzer, hydrogen pump, thermoelectrochemical hydrogen pump, electrochemical hydrogen compressor, redox flow battery, or other electrochemical device.

[0227] In some embodiments, an electrochemical device comprising the reinforced ionomeric polymer membrane as described herein is provided, wherein the electrochemical device is a fuel cell, electrolyzer, hydrogen pump, thermoelectrochemical hydrogen pump, electrochemical hydrogen compressor, redox flow battery, or other electrochemical device. 2296-P9WO -46-EXAMPLES Example 1 General Reinforcement Polymer Preparation

[0228] A layer of ionomeric polymer (in solution / dispersion) was deposited or cast onto a carrier material / substrate. While the layer of ionomeric polymer was still wet, the porous scaffold / mat was laid into the wet polymer layer, and the ionomeric polymer impregnated the porous mat through one face of the porous mat. A further layer of ionomeric polymer was applied to a second face of the porous mat and impregnated the porous mat through the second face. The polymer comprising the impregnated porous mat was dried and suitably annealed to form the reinforced ionomeric polymer membrane. Alternatively, a layer of ionomeric polymer (in solution / dispersion) was deposited or cast onto a carrier material / substrate. While the layer of ionomeric polymer was still wet, the porous scaffold / mat was laid into the wet layer, and the ionomeric polymer impregnated the entirety of the porous mat through to the second face.

[0229] The solution / dispersion of ionomeric polymer may comprise additional components, for example short nanofibers, e.g., from 1 to 50 μm.

[0230] In the final reinforced ionomeric polymer membrane of the disclosure, the weight ratio of ionomeric polymer to scaffold is suitably greater than 70:30 and preferably greater than 90:10. Suitably, the ionomeric polymer to scaffold ratio is less than 98:2.

[0231] The thickness of the porous scaffold in the reinforced ionomeric polymer membrane is suitably distributed through at least about 40%, at least about 50%, at least about 60%, or at least about 70%, of the thickness of the final reinforced ionomeric polymer membrane. The porous mat extends through the thickness of the membrane, such that the thickness of the reinforced ionomeric polymer membrane and the thickness of the porous mat are essentially equal; however, practically, the thickness of the reinforced ionomeric polymer membrane may be slightly thicker than that of the porous mat, such that the thickness of the porous mat is at most 99%, such as 95% of the thickness of the reinforced ionomeric polymer membrane.

[0232] Having the porous scaffold reinforcement distributed through at least about 60% of the thickness of the reinforced ionomeric polymer membrane enhances the stabilization of the final reinforced ionomeric polymer membrane. 2296-P9WO -47-

[0233] A reinforced ionomeric polymer membrane of this disclosure may comprise more than one porous scaffold reinforcement, e.g., two porous scaffolds distributed through at least about 40% of the thickness of the reinforced ionomeric polymer membrane.

[0234] The composite structure of the reinforced ionomeric polymer membrane comprising a porous scaffold and ionomeric polymer may contain sufficient molecular free volume to afford disproportionate water uptake of the reinforced ionomeric polymer membrane in comparison to its volumetric swelling, wherein the latter is restricted. Example 2 Methods for Evaluating Membrane Properties

[0235] A series of 90% functionalized sulfonated polyphenylene-co-non- sulfonated polyphenylene copolymers (“90%-sPP”) were formed into membranes with or without an expanded polytetrafluoroethylene (ePTFE) porous reinforcement by a solvent casting process, yielding reinforced or unreinforced ionomeric membranes, respectively. properties: mechanical properties (tensile strength, tensile strain, elastic modulus, toughness), water sorption and dimensional stability, and / or in-plane and through-plane proton conductivity. Due to potential differences in the planar properties of reinforcements (anisotropy), and hence reinforced membranes produced therefrom, mechanical properties data are presented in both machine direction (MD) and transverse direction (TD). For accurate comparison to reinforced membrane properties, data for unreinforced membranes are provided in duplicate. Therefore, the mechanical properties measured, such as tensile strength, tensile strain, elastic modulus, and toughness of unreinforced membranes, are listed for both MD and TD, with both directions having the same values (i.e., MD = TD for these properties).

[0236] Membrane properties were measured at room temperature (22 ± 1 °C) and in a hot state (80 °C) under dry (dried at 80 °C for at least 2 h), ambient (equilibrated under ambient laboratory conditions for at least 2 h), and / or wet (immersed in DI water for at least 30 min) conditions, as indicated. Water uptake samples were cut to specific dimensions (MD 5 cm x TD 4 cm), using a die cutter. The testing procedure followed ASTM standard D570. Water uptake is represented by percentage increase in weight during immersion, calculated to the nearest 0.01%, per Equation 1:2296-P9WO -48-where Ww is the weight of hydrated membrane and Wd is the weight of dry membrane.

[0237] Dimensional change with respect to the dry state is given by Equation 2,where Sx,y,z is the dimensional change in the machine direction (MD), transverse direction(TD), and membrane thickness (z-direction). Dw is the specific dimension after immersion(typically in cm for the MD and TD, and in μm for the thickness), and Ddis the specific dimension in the dry state.

[0238] Masses least 0.1mg. Thicknesses (defined as z- were a with a resolution of ± 1 μm, while the width and length (x and y dimensions) were measured using a ruler with 0.5 mm precision, or alternatively using a digital flatbed scanner and image analysis software (ImageJ or equivalent).

[0239] The ionic resistance of membranes in the in-plane direction was measuredwith a two-point probe by applying an AC potential sweep over a range of 107-104Hz using an impedance / gain-phase analyzer (Solartron SI 1260 or equivalent) on fully hydrated membranes immersed in liquid water, or at a specified temperature and relative humidity as controlled using an appropriate apparatus (typically an environmental chamber). The analyzer records electrochemical impedance, which can be inputted into a simplified Randles equivalent circuit. The ionic conductivity is calculated using Equation 3, where -1 -1), l is the distance between the probes (in cm), A is thecross-sectional area of the membrane (in cm2), and R is the membrane resistance asdetermined by a fitting to a standard Randle’s circuit model.

[0240] The ionic resistance of membranes in the through-plane direction wasmeasured with a two-probe configuration utilizing a frequency range of 10 MHz to 100 Hz with an amplitude of 100 mV. The electrode area was 5x5 mm. Membrane resistance wasobtained via fitting electrochemical impedance into a suitable simplified equivalent circuit(FIG. 1).conductivity of the membrane, l is the thickness of the test membranes, R is the resistanceof the membrane measured, A is the active area. 2296-P9WO -49-

[0241] Mechanical properties were measured via tensile stress-strain pull tests utilizing samples of material which were cut by a roller die. Tensile stress is defined as the ratio between the load applied (extension in this case) to a given cross-sectional area. The uation 4) is the load applied (in Newtons) divided by the original cross- o) and it is typically presented as percentage of elongation. Mechanical properties of materials are characterized by plotting a curve of tensile stress versus strain. The slope of elastic region of the stress-strain curve is the elastic (or Young’s) modulus and is calculated per equation 6. Toughness (T) of a sample quantifies the total amount of energy a material can absorb before fracturing, and is calculated from the total area under the entire stress-strain curve until sample fracture per Equation 7. (7)

[0242] The effects of reinforcement addition on the membrane mechanical properties of 90%-sPP ionomeric copolymers are demonstrated in FIGS. 2-6 for Unreinforced 1-5 and Reinforced 1-5, prepared as indicated in Table 1 below. The effects of reinforcement thickness is demonstrated in FIGS. 7A and 7B for Unreinforced 6 and 7 and Reinforced 6 and 7, also prepared as indicated in Table 1 below. Table 1 – Preparation of Unreinforced 1-7 and Reinforced 1-7 Membrane Type Ionomeric copolymer Reinforcement Reinforcement )2296-P9WO -50-Reinforced 2 90%-sPP ionomeric ePTFE 4 co ol mersnt type or manufacturing method applied, significant increases in membrane toughness were observed, from 151 to 473% (2.5 to 5.7x of original values) in the MD, and from 197 to 419% (3.0 to 5.2x of original values) in the TD. This was due to increases to both membrane tensile strength and tensile strain. For instance, Reinforced 1 membranes exhibited 22.0 and 24.3% greater tensile strength in the MD and TD, respectively, and 117.4% and 146.2% greater tensile strain in the MD and TD, respectively, versus Unreinforced 1 membranes (FIGS.2A and 2B, respectively). This resulted in 160.8 and 197.4% greater toughness the MD and TD, respectively, for Reinforced 1 membranes (FIG. 2D). Similar, but more pronounced effects were observed when a thicker reinforcement was applied (FIG. 6), 2296-P9WO -51-wherein Reinforced 5 membranes exhibited 100.7 and 95.4% greater tensile stress, 213.4 and 189.1% greater tensile strain, and hence 472.7 and 419.5% greater toughness, in the MD and TD, respectively (FIGS.6A, 6B, and 6D, respectively).

[0244] The changes to elastic modulus were less pronounced and without significant trend, due to the high modulus values of the base 90%-sPP ionomeric copolymers. Elastic modulus after reinforcement integration was either moderately decreased (e.g., -14.9% MD & -16.6% TD per FIG. 2C), statistically unaffected (e.g., per FIG.3C and FIG.5C), or moderately increased (e.g., +36.9% MD & +25.4% TD per FIG. 5C, and +27.0% MD & +24.0% TD per FIG.6C).

[0245] In addition to improving mechanical properties, reinforced membranes prepared with ePTFE reinforcement did not exhibit significant reductions in ex-situ in- plane and through-plane conductivity versus their unreinforced analogues (FIGS. 7A and 7B). For example, incorporation of a thinner (2-5 μm thick) ePTFE reinforcement (FIG. 7A) yielded Unreinforced 6 and Reinforced 6 membrane samples with similar in-plane conductivity values which were within experimental error (137.9 ± 18.7 mS / cm and 125.5 ± 8.8 mS / cm, respectively). Through-plane conductivity measured 112.0 ± 2.2 mS / cm and 121.1 ± 6.0 mS / cm for Unreinforced 6 and Reinforced 6 membrane samples, respectively, indicating no measurable interference from the composite reinforcement on the membrane’s proton conductivity. Incorporation of a thicker (5-8 μm thick) ePTFE reinforcement (FIG. 7B) yielded Unreinforced 7 and Reinforced 7 membrane samples wherein proton conductivity in both the in-plane and through-plane directions were marginally reduced in the reinforced samples, from 141.5 ± 2.07 to 120.0 ± 9.4 mS / cm in- plane, respectively, and 126.1 ± 0.85 to 113.0 ± 2.5 mS / cm through-plane, respectively. Example 3 Sulfonated Reinforced Membrane Polymer Mechanical Property Characterization

[0246] A series of 100% functionalized sulfonated polyphenylene polymers (“100%-sPP”) were formed into membranes without any reinforcement (unreinforced), or with an expanded polyethylene (ePE) porous reinforcement, or with an expanded polytetrafluoroethylene (ePTFE) porous reinforcement by solvent casting process, yielding unreinforced, e-PE reinforced (A), or ePTFE-reinforced (B) ionomeric membranes, respectively, denoted Unreinforced 8, Reinforced 8A, or Reinforced 8B, respectively. Unreinforced 8 and Reinforced 8A and 8B are prepared as indicated in Table 2 below. Table 2 – Preparation of Unreinforced 8 and Reinforced 8A and 8B 2296-P9WO -52-Membrane Type Ionomeric copolymer Reinforcement Reinforcement T e thickness ( m)properties, and / or water sorption and dimensional stability, and / or in-plane and through- plane proton conductivity using methods described in Example 2. Data are reported in FIGS.8A-8E.

[0248] Significant increases in mechanical properties were observed as a result of reinforcement with ePE when comparing Unreinforced 8 vs. Reinforced 8A membrane samples. For instance, tensile strength increased 31.5% in the MD and 141.5% in the TD (FIG.8A), and tensile strain increased 269.5% in the MD and 182.0% in the TD (FIG.8B). While elastic modulus values exhibited modest decreases of 33.1 and 16.3% in the MD and TD, respectively (FIG.8C), calculated membrane toughness was 387.4 and 645.8% higher in the MD and TD, respectively (FIG.8D) for Reinforced 8A membrane samples.

[0249] Significant increases in mechanical properties were also observed as a result of reinforcement with ePTFE when comparing Unreinforced 8 vs. Reinforced 8B membrane samples. For example, tensile strength and strain increases of 22.3% and 263.9% (MD), respectively, and 15.6% and 301.0% (TD), respectively, were observed. Elastic modulus values again exhibited modest decreases of 30.7 and 40.3% in the MD and TD, respectively (FIG. 8C). Calculated membrane toughness increased by 347.3 and 333.6% in the MD and TD, respectively (FIG.8D).

[0250] Membrane in-plane proton conductivity was not statistically different between Unreinforced 8, Reinforced 8A, and Reinforced 8B membrane samples (126.9 ± 18.1 vs.124.5 ± 4.0 vs.127.2 ± 6.9 mS / cm in-plane, respectively). Samples of Reinforced 8A exhibited a 59.4% reduction in through-plane conductivity (50.0 ± 5.6 mS / cm) vs. samples of Unreinforced 8 (123.2 ± 0.9 mS / cm). In contrast, Reinforced 8B membrane samples exhibited only minor (14.5%) reductions in through-plane conductivity (105.4 ± 2296-P9WO -53-6.8 mS / cm) vs. samples of Unreinforced 8 (123.2 ± 0.9 mS / cm). Data are reported in FIG. 8E. Example 4 Sulfonated Polymer Membrane Water Sorption and Dimensional Stability Characterization

[0251] A series of 100% functionalized sulfonated polyphenylene polymers (“100%-sPP”) were formed into membranes without any reinforcement (unreinforced), or with an expanded polyethylene (ePE) porous reinforcement, or with an expanded polytetrafluoroethylene (ePTFE) porous reinforcement, or with an electrospun poly(benzimidazole) (e-spun PBI) porous reinforcement, by solvent casting process, yielding unreinforced, ePE-reinforced (A), ePTFE-reinforced (B), or e-spun PBI- reinforced (C) ionomeric membranes, respectively, denoted Unreinforced 9 and Reinforced 9A, 9B, or 9C, respectively. Unreinforced 9 and Reinforced 9A, 9B, and 9C are prepared as indicated in Table 3 below. Table 3 – Preparation of Unreinforced 9 and Reinforced 9A, 9B, and 9C Membrane Type Ionomeric copolymer Reinforcement Reinforcement )and dimensional stability properties using methods described in Example 2. Volumetric swelling (Sxyz) was calculated via Equation 8, where Sx, Sy, and Sz are the dimensional change in the machine direction (MD), transverse direction (TD), and membrane thickness (z-direction), respectively, in percentage. Data are presented in FIG.9. 2296-P9WO -54-(%) = 1 + × 1 + × 1 + 1 × 100 (8)to membrane waterwater uptake values which were lower by a factor of 2.6-3.1x at RT and 2.9-3.4x at 80 °C versus that of Unreinforced 9 membranes (FIG.9A). Water uptake was lowest in Reinforced 9C samples (119.6 ± 4.48 wt% and 191.0 ± 6.07 wt% at RT and 80 °C, respectively) potentially due to the anticipated chemical interactions between the aromatic, acidic sulfonate moieties on 100%-sPP and the aromatic, basic benzimidazole moieties on the PBI reinforcement. All membrane swelling parameters (Sx, Sy, Sz) were reduced as a result of reinforcement integration. For example, samples of Unreinforced 9 exhibited thickness, MD, and TD swelling values of 328.0 ± 8.2, 32.4 ± 0.8, and 34.8 ± 0.87%, respectively, at 80 °C, whereas samples of Reinforced A exhibited values of 203.0 ± 7.3, 5.2 ± 0.8, and 8.7 ± 2.7%, respectively, under the same conditions (FIGS.9B, 9C, 9D). This is further exemplified by the calculated volumetric swelling of each membrane type (FIG.9E): 438.3, 168.0, 176.5, and 155.6 vol%, respectively, at RT, and 663.9, 246.5, 266.0, and 241.5 vol%, respectively, at 80 °C, for Unreinforced 9, Reinforced 9A, or Reinforced 9B, and Reinforced 9C membranes. Example 5 Copolymer e-spun PBI Reinforcement Membrane Water Sorption and Dimensional Stability Property Characterization

[0254] A series of 90% functionalized sulfonated polyphenylene-co-non- sulfonated polyphenylene copolymers (“90%-sPP”) were formed into membranes without any reinforcement (Unreinforced 10), or with an electrospun poly(benzimidazole) (e-spun PBI) porous reinforcement, by solvent casting process, yielding unreinforced or e-spun PBI-reinforced (Reinforced 10A) membranes, respectively. Unreinforced 9, Reinforced 9A, Reinforced 9B, and Reinforced 9C are prepared as indicated in Table 4 below. Table 4 – Preparation of Unreinforced 10 and Reinforced 10A Membrane Type Ionomeric copolymer Reinforcement Reinforcement )2296-P9WO -55-Reinforced 10A 90%-sPP ionomeric e-spun PBI 15 co ol mers r sorptiony p p g p . olumetric swelling (Sxyz) was calculated via Equation 8 in Example 4. Data are presented in FIGS. 10A-10F.

[0256] When compared to Unreinforced 10 membranes, the e-spun PBI-containing Reinforced 10A membranes exhibited generally reduced water uptake (FIG. 10A), thickness swelling, (FIG.10B), MD planar swelling (FIG.10C), TD planar swelling (FIG. 10D), and volumetric swelling (FIG. 10E). Water uptake, thickness swelling, MD planar swelling, TD planar swelling, and volumetric swelling were measured at 80 °C, and reductions of 50%, 49%, 50%, 49%, and 56%, respectively, were observed. Furthermore, in-plane and through-plane conductivity were not adversely affected as a result of e-spun PBI reinforcement introduction. Namely, the in-plane conductivity of Unreinforced 10 membranes and Reinforced 10A membranes were 106.5 ± 12.3 mS / cm and 110.4 ± 7.1 mS / cm, respectively, whereas through-plane conductivity values were 107.5 ± 5.0 mS / cm and 142.5 ± 24.5 mS / cm, respectively. Example 6 Fuel Cell Performance of Membrane Electrode Assemblies for Reinforced Copolymer Membranes

[0257] A series of 90% functionalized sulfonated polyphenylene-co-non- sulfonated polyphenylene copolymers (“90%-sPP”) were formed into membranes with an expanded polytetrafluoroethylene (ePTFE) porous reinforcement, or with an electrospun poly(benzimidazole) (e-spun PBI) porous reinforcement, or with an expanded polyethylene (ePE) porous reinforcement, by solvent casting process, yielding ePTFE-reinforced (Reinforced 11A, 15.1 ± 0.8 μm), e-spun PBI-reinforced (Reinforced 11B, 23.5 ± 1.5 μm), or ePE-reinforced (Reinforced 11C, 12.2 ± 0.3 μm) membranes, respectively. Samples from each membrane type were evaluated for use in hydrogen fuel cells to determine in- situ performance, as described below, and compared against two 15 μm thickness reinforced PFSA reference materials (PFSA 1 and PFSA 2). Data are presented in FIGS. 11A-11F. Reinforced 11A, 11B, and 11C, and PFSA 1 and PFSA 2, are prepared as indicated in Table 5A below. Physical properties of PFSA 1 and 2 are presented in Tables 5B and 5C. 2296-P9WO -56-Table 5A – Preparation of Reinforced 11A, 11B, and 11C, and PFSA 1, and PFSA 2 Membrane Type Ionomeric copolymer Reinforcement Reinforcement T thi k m) RHS S151 ± 11 14 ± 14PFSA 1 PFSA 2 9st powder (TKK TEC-10e40e, comprising 36.9 wt% Pt on graphitized carbon) in 2:1 IPA:H2O solvent, to which was added ionomer solution (Nafion®D520) dropwise under rapid stirring. The final catalyst ink mixture contained 1 wt% solids (0.70 wt% Pt / C catalyst powder and 0.30 wt% ionomer) in 2:1 IPA:H2O. Catalyst coated membranes (5 cm2electrode area) were prepared by ultrasonic spray coating (Sono-Tek ExactaCoat SC) of the aforementioned catalyst inks 2296-P9WO -57-onto specific membranes. Both cathode and anode Pt loadings were 0.4 mg cm-2each. The CCMs were assembled in fuel cell hardware for testing using commercial gas diffusion layers with microporous layers (Freudenberg H14C15) and Kapton®total gasketing). The testing was performed on TP5eV2 produced from Tandem Technologies. The test hardware utilizes a bladder pressure system for compression. The compression of the cell hardware was optimized for 160 psi. Optimization of the compression was achieved when no further reduction in the specific area resistance was measured. In-situ fuel cell characterization was performed on a Teledyne®Medusa RD, Model 890CL fuel cell test station.

[0259] Upon assembly, the cell temperature and humidifiers were set to 80 C. Anitrogen purge was conducted for 5 minutes before switching to H2 / Air at 0.25 / 0.5 SLPM. Both gases were then pressurized to 150 kPagauge. Once OCV stabilized, current was slowly ramped by 5 mA / s increments until 0.65 V potential was achieved. This was designed towet the catalyst layer and prevent auto-ignition. A fast break-in protocol consisting of 30cycles of 0.6V, 0.3V, and 0.05A, was then conducted with each step held for 1 minute, for a total of 1.5 hours.

[0260] To obtain polarization data, cells were held at 80 °C under pure H2 / Air (0.25 / 0.5 slpm) at 150 kPag backpressure and anode / cathode relative humidities (RH) of 100% / 100%, 100% / 30%, or 30% / 30%. The cells were ramped from 0 A to 15 A, at a rate of 3 minutes per point, and at increments of 1 point per step. The average current over the three minutes was taken.

[0261] In preparation for electrochemical measurements, the cell and humidifierswere held at 80 C (100% RH) with each of the gases, H2 / N2 being run at 0.5 / 0.5 SLPM,and 150 / 150 kPag, respectively. Once the cell potential was stable (below at most 0.150 V), linear sweep voltammetry was measured. The cell was swept from 0.1 to 0.6 V at a scan rate of 0.005 V / s. This was run to ensure there was no short in the cell. Upon completion of each experiment, no short was found. Subsequently, chronoamperometry measurements were performed to measure hydrogen crossover current. The cell was ramped from 0.1 to 0.6 V with the cell being held for 60 s at each step, except for an extended 120 s hold at 0.5 V. To ensure stabilization, the average current of the last minute of the 0.5 V hold was used as the crossover metric. A resulting current density was derived by taking this average current value and dividing it by the active area, resulting in a unit of mA / cm2. Both measurements utilized a VersaStat®Potentiostat. 2296-P9WO -58-

[0262] Under fully humidified conditions (100 / 100% RH anode / cathode), MEAs comprising Reinforced 11A, 11B, and 11C membranes exhibited high performance and low area-specific resistance (ASR) which compared favorably to MEAs comprising the PFSA reference materials. For example, under 100 / 100% RH at 1.6 A / cm2, the voltage exhibited by MEAs comprising Reinforced 11A, 11B, 11C, PFSA 1, and PFSA 2 were 0.660, 0.653, 0.648, 0.654, and 0.641 V, respectively, with ASR values of 37.2, 37.6, 39.1, 35.8, and 39.9 mOhm·cm2, respectively. Similar trends were measured under partially humidified conditions (100 / 30% RH anode / cathode). However, the ASR of Reinforced 11C increased disproportionately vs. Reinforced 11A, Reinforced 11B, PFSA 1, and PFSA 2. For example, under 100 / 30% RH at 1.6 A / cm2, the voltage exhibited by MEAs comprising Reinforced 11A, 11B, 11C, PFSA 1, and PFSA 2 were 0.655, 0.653, 0.624, 0.640, and 0.619 V, respectively, with ASR values of 43.6, 47.8, 57.2, 43.7, and 50.0 mOhm·cm2, respectively.

[0263] Under dry conditions (30 / 30% RH anode / cathode), MEAs comprising Reinforced 11C exhibited disproportionately higher ASR, as well as poorer performance. However, MEAs comprising both Reinforced 11A and 11B membranes continued to exhibit comparable performance and ASR versus MEAs comprising the PFSA reference materials. For example, under 30 / 30% RH at 1.6 A / cm2, the voltage exhibited by MEAs comprising Reinforced 11A, 11B, 11C, PFSA 1, and PFSA 2 was 0.592, 0.584, 0.457, 0.561, and 0.511 V, respectively, with ASR values of 64.8, 67.4, 109.0, 64.9, and 79.6 mOhm·cm2, respectively. Hydrogen crossover current values, measured via chronoamperometry under 100 / 100% RH, were 2.7, 2.0, 3.4, 10.3, and 8.1 mA / cm² for MEAs comprising Reinforced 11A, 11B, 11C, PFSA 1, and PFSA 2, respectively. Example 7 Reinforced Copolymer Characterization of Water Sorption and Dimensional Stability

[0264] A series of 90% functionalized sulfonated polyphenylene-co-non- sulfonated polyphenylene copolymers (“90%-sPP”) was formed into membranes without any reinforcement (unreinforced), with a non-woven polyphenylene sulfide (PPS) porous reinforcement by solvent casting process, or with an expanded polyethylene (ePE) porous reinforcement, yielding unreinforced (Unreinforced 12) membranes, PPS-reinforced (Reinforced 12A) membranes, or ePE-reinforced (Reinforced 12B) membranes, respectively. Unreinforced 12 and Reinforced 12A and 12B are prepared as indicated in 2296-P9WO -59-Table 6A below. Physical properties of Reinforced 12A and 12B are presented in Tables 6B and 6C. Table 6A – Preparation of Unreinforced 12 and Reinforced 12A and 12B Membrane Type Ionomeric copolymer Reinforcement Reinforcement m) RHReinforced 12A Reinforced 12B58.5 ± 3.5 15 ± 1Reinforced 12A Reinforced 12Band dimensional stability properties using methods described in Example 2. Volumetric swelling (Sxyz) was calculated via Equation 8 in Example 4. The water uptake to volumetric swelling ratio was calculated by dividing the former by the latter under a given set of conditions, as shown in Equation 9 below. Data are presented in FIGS.12A-12F. =(%)(9)2296-P9WO -60-

[0266] Unreinforced 12 membranes exhibited increased water uptake and dimensional swelling properties in all conditions when compared to either Reinforced 12A or Reinforced 12B membranes. For example, after immersion in liquid water at 80 °C, the water uptake value measured for Unreinforced 12 membranes was 268.6 ± 7.3 wt%, whereas for membranes reinforced with PPS (Reinforced 12A) or with ePE (Reinforced 12B), this value was, 165.1 ± 3.2 wt% and 144.3 ± 8.2 wt%, respectively. Addition of either reinforcement greatly reduced in-plane swelling (MD and TD dimensions, FIGS.12C and 12D), however, this effect was far more pronounced with the PPS reinforcement (Reinforced 12A). For example, the MD and TD dimensional swelling of Unreinforced 12 membranes after immersion in liquid water at 80 °C was 20.1 ± 0.4 and 20.0 ± 0.6%, respectively, whereas for Reinforced 12A membranes, these values were 0.1 ± 0.1 and 0.1 ± 0.1%, respectively, and for Reinforced 12B membranes, these values were 4.2 ± 0.1 and 5.3 ± 0.1%, respectively (FIG.12D). A similar trend was noted in the case of thickness (Z- direction) swelling at both room temperature and 80 °C. For example, the thickness swelling of Unreinforced 12 membranes (189.5 ± 15.4%) was notably greater than that of Reinforced 12A (81.5 ± 3.3%) or Reinforced 12B (126.7 ± 0.5%) membranes at 80 °C, with a similar trend at room temperature (FIG.12B).

[0267] The reduction in swelling observed in the case of the reinforced membrane samples, in particular Reinforced 12A, yielded significantly reduced hygrothermal volumetric swelling parameters (FIG.12E). For instance, at 80 °C, the volumetric swelling of Unreinforced 12 samples (317.3 vol%) was nearly 4x that of Reinforced 12A samples (81.9 vol%) and more than 2x that of Reinforced 12B samples (148.7%). When compared to the water uptake values measured under these conditions, the water uptake to volumetric swelling ratios for the membranes was in the order of Reinforced 12A > Reinforced 12B > Unreinforced 12. The ratio was significantly higher in the case of Reinforced 12A membranes, indicating that samples were capable of absorbing significantly more water per volumetric area of membrane than Unreinforced 12 membranes without experiencing detrimental deformation in the form of both planar (X and Y, or MD and TD, respectively) and thickness (Z) swelling. 2296-P9WO -61-Example 8

[0268] PFAS-Free Reinforcement Properties and Composite Membrane Mechanical, Water Sorption and Dimensional Stability Property Characterization

[0269] Inventive samples containing mechanical reinforcements shown in Table 7B, 7C, and 7D were prepared and characterized as described in Examples 1, 2, 3, and 4, with Reinforced 13, 13A, 13B, 13C, and 13D prepared as indicated in Table 7A below. Table 7A – Preparation of Reinforced 13, 13A, 13B, 13C, and 13D Membrane Type Ionomeric copolymer Reinforcement Reinforcement ) make upReinforced 13 (ePTFE) are compared to PFAS-free alternative Reinforced 13A (electrospun PBI), Reinforced 13B (electrospun PESU), Reinforced 13C (wet laid liquid crystal polymer [melt polymerized 4-hydroxybenzoic acid {HBA} and 6- hydroxynaphthalene-2-carboxylic acid {HNA}], and Reinforced 13D (wet laid PPS) PEMs. As shown in Table 7B, these reinforcement materials comprise a range of thicknesses, weights, porosities, force-displacement and air permeation values. Table 7B – Physical properties of reinforcement layers Force- . 2-2296-P9WO -62-Reinforced 13A 15 3 85 0.13 0.13 5 R i f 1 B 11 7 14 Mswere prepare as escr e n xamp e an e r mec an ca proper es were eva uated as described in Examples 2 and 3. As shown in Table 7C, composite reinforced PEMs were obtained of similar thicknesses to ePTFE baselines (Reinforced 13A), using alternative PFAS-free reinforcements (Reinforced 13A, 13B, 13C, and 13D), which yield tensile stress, tensile strain, elastic modulus, and toughness properties of similar magnitude to baseline Reinforced 13 PEM, which are all generally uniform in the MD and TD, indicating these materials are suitable for operation in a fuel cell device. Compared to Reinforced 13, Reinforced 13A, B, C, and D all exhibit slightly lower tensile strain and toughness values, indicative of more brittle PEMs, which may be caused by incorporation of non-elastomeric reinforcements. Elastic modulus of the reinforced PEMs is correlated to force-displacement properties of the reinforcement layers, themselves, as indicated in Table 7B. Table 7C – Mechanical properties of composite reinforced PEMs under ambient conditions Tensile Tensile strain Elastic modulus Toughness S m l Thi kn ± 5 ± 4 ± ±2296-P9WO -63-

[0272] The conductivity, water uptake and dimensional change properties of composite PEMs upon exposure to 80 °C liquid water are shown in Table 7D, which are of the same magnitude between the baseline Reinforced 13 and PFAS-free Reinforced 13A, 13B, 13C, and 13D. Water uptake is higher in the electrospun PBI and PESU reinforced PEMs (Reinforced 13A and 13B), which may be attributed to the incorporation of high- surface area, hygroscopic nanofibers, however the resulting through plane proton conductivity is . Water uptake of Reinforced 13D is lower than Reinforced 13, 13A, 13B, and 13C, which corresponds to a reduced through plane proton conductivity. Dimensional change upon hydration is similar between Reinforced 13, 13A, 13B, 13C, and 13D in the thickness direction. There are minor variations in the MD and TD in plane swelling values, however they are all of the same magnitude, implying suitability in long term fuel cell testing. The nature of anisotropic in plane swelling, particularly in Reinforced 13C, may be related to anisotropic strain-displacement of the reinforcement layer, as indicated in Table 7B. Table 7D – Conductivity and dimensional change properties reinforced membranes in 80C Through- In plane (XY) Water 5 5 5 12296-P9WO -64-

[0273] While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. 2296-P9WO -65-

Claims

CLAIMS The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A reinforced ionomeric polymer membrane comprising an ionomeric polymer and a porous scaffold reinforcement, wherein the ionomeric polymer comprises a repeat unit (x) of Formula (I), wherein Formula (I) has the structure: R1ER1D1Hwherein: R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO-X+; R1Gand R1Hare independently H, aryl, or heteroaryl, wherein said aryl and heteroaryl are each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituentsindependently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO-X+; A1is arylene, heteroarylene, aralkylene, or heteroaralkylene, each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; A2is absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; L1is an unsubstituted or substituted linking heteroatom, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; 2296-P9WO -66-L2and L3are independently absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1- 6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and X+is H+, a cation, an alkali metal ion, or [N(RA)(RB)(RC)(RD)]+wherein RA, RB, RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

2. The reinforced ionomeric polymer membrane of Claim 1, wherein the ionomeric polymer further comprises a repeat unit (y) of Formula (II), wherein Formula (II) has the structure: R2ER2D1Hwherein: R2A, R2B, R2C, R2D, R2E, and R2Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, and cyano; R1Gand R1Hare independently H, aryl, or heteroaryl, wherein said aryl and heteroaryl are each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO- X+; B1is arylene, heteroarylene, aralkylene, or heteroaralkylene, each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; B2is absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; L1is an unsubstituted or substituted linking heteroatom, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; 2296-P9WO -67-L2and L3are independently absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and X+is H+, a cation, an alkali metal ion, or [N(RA)(RB)(RC)(RD)]+wherein RA, RB, RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

3. The reinforced ionomeric polymer membrane of any one of Claims 1 or 2, having a structure of Formula (III): R1ER2BR1DR2Aywherein: R1A, R1B, R1C, R1D, R1E, and R1Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO-X+, and provided that at least R1Fare independently aryl or heteroaryl substitutedselected from SO3-X+, PO32-2X+, and COO- X+; R2A, R2B, R2C, R2D, R2E, and R2Fare independently aryl or heteroaryl, each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, and cyano; R1Gand R1Hare independently H, aryl, or heteroaryl, wherein said aryl and heteroaryl are each unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents independently selected from C1-6alkyl, halo, nitro, cyano, SO3-X+, PO32-2X+, and COO- X+; A1and B1are independently arylene, heteroarylene, aralkylene, or heteroaralkylene, each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; 2296-P9WO -68-A2and B2are independently absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; L1is an unsubstituted or substituted linking heteroatom, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; L2and L3are independently absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1- 6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and X+is H+, a cation, an alkali metal ion, or [N(RA)(RB)(RC)(RD)]+wherein RA, RB, RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

4. The reinforced ionomeric polymer membrane of any one of Claims 1-3, having a structure of Formula (IV): R3R4wherein: R3, R4, R5, and R6are independently selected from H, SO3-X+, PO32-2X+, and COO-X+; R7, R8, R9, and R10are independently selected from H, C1-6alkyl, halo, nitro, and cyano; A1and B1are independently arylene, heteroarylene, aralkylene, or heteroaralkylene, each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; 2296-P9WO -69-A2and B2are independently absent, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, or heteroaralkylene, are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; L1is independently an unsubstituted or substituted linking heteroatom, arylene, heteroarylene, aralkylene, or heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; L2and L3are independently absent, arylene, heteroarylene, aralkylene, and heteroaralkylene, wherein said arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl; and X+is H+, a cation, an alkali metal ion, or [N(RA)(RB)(RC)(RD)]+wherein RA, RB, RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

5. The reinforced ionomeric polymer membrane of any one of Claims 2-4, wherein A1, B1, or both A1and B1are independently arylene, unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; and A2, B2, or both A2and B2are absent. 6 The reinforced ionomeric polymer membrane of any one of Claims 2-5, wherein L1is naphthalenylene, phenylene, or C1-6alkyl-substituted phenylene, and L2and L3are independently absent or phenylene, wherein when present, each phenylene is unsubstituted or substituted with 1, 2, 3, or 4 substituents independently selected from C1-6alkyl and halo, and wherein L1of Formula (I) is the same or different from L1of Formula (II), L2of Formula (I) is the same or different from L2of Formula (II), and L3of Formula (I) is the same or different from L3of Formula (II).

7. The reinforced ionomeric polymer membrane of any one of Claims 1-6, wherein the repeat unit (x) of Formula (I) is selected from: 2296-P9WO -70-+ 3 S3X+ SO X O X+ - , RA,8. The reinforced ionomeric polymer membrane of any one of Claims 1-7, wherein the repeat unit (x) of Formula (I) is selected from: 2296-P9WO -71-SO+ 3XSO3X+ , ,RC, and RDare independently H, C1-6alkyl, aryl, or heteroaryl.

9. The reinforcedpolymer membrane of any one of Claims 2-8, wherein the repeat unit (y) of Formula (II) is selected from: 2296-P9WO -72-. f Claims 2-9, wherein the repeat unit (y) of Formula (II) is selected from: m ,2296-P9WO -73-m .

11. The reinforced ionomeric polymer membrane of any one of Claims 1-10, wherein the ionomeric polymer further comprises a branching comonomer M1, wherein M1is selected from an unsubstituted or substituted linking atom, arylene, heteroarylene, aralkylene, heteroaralkylene, and combinations thereof, wherein the linking atom, arylene, heteroarylene, aralkylene, and heteroaralkylene are each unsubstituted or substituted with 1, 2, or 3 substituents independently selected from C1-6alkyl, halo, nitro, cyano, aryl, and heteroaryl.

12. The reinforced ionomeric polymer membrane of any one of Claims 1-11, wherein each L3, L2, and L1of –L3–L2–L1–, and each L3and L2, of –L3–L2–M1–, when present, are independently selected from: , , ,2296-P9WO -74-, , and 1 is bound through a covalent bond to at least 3 sulfonated polyphenylene repeat units, hydrophobic polyphenylene repeat units, or a combination thereof, and wherein M1is selected from the group consisting of: .wherein the ionomeric polymer has a branched structure of Formula (V): 2296-P9WO -75-R1ER1Dwherein P1and Formula (I) and a repeat unit (y) of Formula (II).

15. The reinforced ionomeric polymer membrane of any one of Claims 12-14, wherein the ratio of z / (x+P1+P2) is less than 0.

2.

16. The reinforced ionomeric polymer membrane of any one of Claims 2-15, wherein the mole percent of x is about 59% to about 99%, and the mole percent of y is about 41% to about 1%.

17. The reinforced ionomeric polymer membrane of any one of Claims 2-16, wherein the mole percent of x is about 90%, and the mole percent of y is about 10%.

18. The reinforced ionomeric polymer membrane of any one of Claims 2-17, wherein the ionomeric polymer is a random copolymer comprising a random distribution of x and y.

19. The reinforced ionomeric polymer membrane of any one of Claims 2-18, wherein the ionomeric polymer is a statistical copolymer comprising an average composition ratio of x and y.

20. The reinforced ionomeric polymer membrane of any one of Claims 2-19, wherein the ionomeric polymer is a block copolymer, wherein: x is an integer from 3 to 100, y is an integer from 3 to 100; and wherein a mole ratio of the first block to the second block ranges from 1:99 to 99:

1.

21. The reinforced ionomeric polymer membrane of any one of Claims 1-20, wherein the porous scaffold reinforcement comprises a plurality of nanofibers, wherein the plurality of nanofibers are from about 1 μm to about 50 μm in length. 2296-P9WO -76-22. The reinforced ionomeric polymer membrane of Claim 21, wherein the plurality of nanofibers comprises a non-ionically conducting heterocyclic-based polymer.

23. The reinforced ionomeric polymer membrane of Claim 21, wherein the plurality of nanofibers comprises a non-ionically conducting aryl-based polymer, heteroaryl-based polymer, or combinations thereof, and wherein the aryl-based polymer, heteroaryl-based polymer, or combinations thereof are independently unsubstituted or substituted with alkyl groups, heteroatomic groups, or combinations thereof.

24. The reinforced ionomeric polymer membrane of any one of Claims 21-23, wherein the plurality of nanofibers comprises one or more polymer building blocks selected from the group consisting of: polysulfone (PSU), polyimide (PI), polyphenylene oxide (PPO), polyphenylene sulfoxide (PPSO), polyphenylene sulfide (PPS), polyphenylene sulfide sulfone (PPS / SO), polyparaphenylene (PPP), polyphenylduinoxaline (PPQ), polyarylketone (PK) polyethersulfone (PES), polyetherethersulfone (PEES), polyarylsulfone, polyarylethersulfone (PAS), polyphenylene sulfone (PPSU), polyphenylenesulfone (PPSO), polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketone-ketone (PEKK), polyetheretherketone-ketone (PEEKK) polyetherketoneetherketone-ketone (PEKEKK) polymers, polyphenylene sulfide (PPS), polyarylate, liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polypropylene (PP), polyethylene (PE), polyester, polyamide, polystyrene, polyvinyl chloride (PVC), polybenzoxazole (PBO), polybenzothiazole (PBT), polybenzimidazole (PBI), polyamide (PA), polyimide (PI), glass fiber, cellulose, aramid, polypara-phenylene terephthalamide (PPTA), and a combination thereof.

25. The reinforced ionomeric polymer membrane of any one of Claims 21-24, wherein the plurality of nanofibers is woven, stretched, drawn, made by electrospinning, wet-laid, or dry-laid, into a scaffold, sheet, or mat.

26. The reinforced ionomeric polymer membrane of any one of Claims 1-20, wherein the porous scaffold reinforcement comprises one or more woven materials.

27. The reinforced ionomeric polymer membrane of Claim 26, wherein the one or more woven materials are selected from woven PEEK, woven PAEK, woven PPS, woven polyarylate or liquid crystal polymer (LCP), woven PTFE, woven PP, woven PE, woven polyester, woven polyamide, or a combination thereof.

28. The reinforced ionomeric polymer membrane of any one of Claims 1-20, wherein the porous scaffold reinforcement comprises one or more stretched materials. 2296-P9WO -77-29. The reinforced ionomeric polymer membrane of Claim 28, wherein the one or more stretched materials are selected from expanded PE, expanded PTFE, expanded PP, expanded PMP, expanded polystyrene, expanded PVC, or a combination thereof.

30. The reinforced ionomeric polymer membrane of any one of Claims 1-20, wherein the porous scaffold reinforcement comprises one or more electrospun materials.

31. The reinforced ionomeric polymer membrane of Claim 30, wherein the one or more electrospun materials are selected from electrospun PBI, electrospun PI, electrospun PEEK, electrospun PPS, electrospun PPSU, electrospun polyamide, or a combination thereof.

32. The reinforced ionomeric polymer membrane of any one of Claims 1-20, wherein the porous scaffold reinforcement comprises one or more non-woven materials.

33. The reinforced ionomeric polymer membrane of Claim 32, wherein the one or more non-woven materials are selected from wet-laid polyphenylene sulfide (PPS), wet- laid polybenzimidazole (PBI), wet-laid polyimide, wet-laid polyester, wet-laid glass fiber, wet-laid cellulose, dry-laid aramid, dry-laid polyethylene, dry-laid polypropylene, dry-laid polyester, or a combination thereof.

34. The reinforced ionomeric polymer membrane of any one of Claims 1-33, wherein the porous scaffold reinforcement is impregnated with the ionomeric polymer.

35. The reinforced ionomeric polymer membrane of any one of Claims 1-34, wherein the porous scaffold reinforcement comprises a first face and a second face, wherein the first face of the porous scaffold reinforcement is impregnated with a first liquid ionomeric polymer solution, and wherein the second face of the porous scaffold reinforcement is impregnated with a second liquid ionomeric polymer solution, and wherein the first liquid ionomeric polymer solution is the same or different from the second liquid ionomeric polymer solution.

36. The reinforced ionomeric polymer membrane of any one of Claims 1-35, wherein the porous scaffold reinforcement has a pore diameter ranging from about 0.05 to about 10 .

37. The reinforced ionomeric polymer membrane of any one of Claims 1-36, wherein the porous scaffold reinforcement has a porosity range from about 40% to about 95%.

38. The reinforced ionomeric polymer membrane of any one of Claims 1-37, wherein the porous scaffold reinforcement is heat treated, pressure treated, or a 2296-P9WO -78-combination thereof, prior to incorporation into the reinforced ionomeric polymer membrane.

39. The reinforced ionomeric polymer membrane of any one of Claims 1-38, wherein the porous scaffold reinforcement is plasma treated prior to incorporation into the reinforced ionomeric polymer membrane.

40. The reinforced ionomeric polymer membrane of any one of Claims 1-39, wherein the porous scaffold reinforcement has a thickness of less than about 100 μm.

41. The reinforced ionomeric polymer membrane of any one of Claims 1-40, wherein the reinforced ionomeric polymer membrane has a thickness of about 10 μm to about 200 μm.

42. The reinforced ionomeric polymer membrane of any one of Claims 1-41, wherein the reinforced ionomeric polymer membrane has a thickness of less than about 100 μm.

43. The reinforced ionomeric polymer membrane of any one of Claims 1-42, wherein the reinforced ionomeric polymer membrane has a thickness of less than about 50 μm.

44. The reinforced ionomeric polymer membrane of any one of Claims 1-43, wherein the reinforced ionomeric polymer membrane has a thickness of less than about 20 μm.

45. The reinforced ionomeric polymer membrane of any one of Claims 1-44, wherein the reinforced ionomeric polymer membrane has a thickness, and the porous scaffold reinforcement comprises at least about 20% of the thickness of the reinforced ionomeric polymer membrane.

46. The reinforced ionomeric polymer membrane of any one of Claims 1-45, wherein the ionomeric polymer membrane has a thickness, and the porous scaffold reinforcement is distributed through at least about 50% of the thickness of the ionomeric polymer membrane.

47. The reinforced ionomeric polymer membrane of any one of Claims 1-46, wherein the ionomeric polymer membrane has a thickness, and the porous scaffold reinforcement is distributed through at least about 70% of the thickness of the ionomeric polymer membrane. 2296-P9WO -79-48. The reinforced ionomeric polymer membrane of any one of Claims 1-47, wherein the weight ratio of the ionomeric polymer to the porous scaffold reinforcement is greater than about 70:

30.

49. The reinforced ionomeric polymer membrane of any one of Claims 1-48, wherein the weight ratio of the ionomeric polymer to the porous scaffold reinforcement is greater than about 90:

10.

50. The reinforced ionomeric polymer membrane of any one of Claims 1-49, wherein an in-plane (x, y direction) swelling upon hydration is less than about 10%.

51. A method for preparing the reinforced ionomeric polymer membrane according to any one of Claims 1-50, the method comprising: impregnating the porous scaffold reinforcement with a liquid ionomeric polymer solution comprising the ionomeric polymer; and forming a composite of the porous scaffold reinforcement and the ionomeric polymer.

52. The method of Claim 51, wherein the liquid ionomeric polymer solution comprising the ionomeric polymer further comprises a plurality of particulates or nanofibers, wherein the particulates or nanofibers have a length of about 1 μm to about 50 μm.

53. The method of Claim 51 or 52, wherein the liquid ionomeric polymer solution is a first liquid ionomeric polymer solution, and wherein the method further comprises impregnating the porous scaffold reinforcement with a second liquid ionomeric polymer solution, and wherein the first ionomeric polymer solution and second ionomeric polymer solution are the same or are different.

54. The method of any one of Claims 51-53, wherein the porous scaffold reinforcement comprises a first face and a second face, and wherein impregnating the porous scaffold reinforcement comprises: impregnating the first face of the porous scaffold reinforcement with a first liquid ionomeric polymer solution; and impregnating the second face of the porous scaffold reinforcement with a second liquid ionomeric polymer solution, wherein the first liquid ionomeric polymer solution is the same or different from the second liquid ionomeric polymer solution. 2296-P9WO -80-55. The method of any one of Claims 51-54, wherein the method further comprises: forming the porous scaffold reinforcement from a plurality of nanofibers.

56. The method of Claim 55, wherein forming the porous scaffold reinforcement comprises drawing, stretching, electrospinning, wet-laying, dry-laying, or weaving the plurality of nanofibers into a scaffold, sheet, or mat.

57. The method of any one of Claims 51-56, wherein the method further comprises forming the porous scaffold reinforcement from one or more woven materials.

58. The method of any one of Claims 51-57, wherein the method further comprises forming the porous scaffold reinforcement from one or more stretched materials.

59. The method of any one of Claims 51-58, wherein the method further comprises forming the porous scaffold reinforcement from one or more electrospun materials.

60. The method of any one of Claims 51-59, wherein the method further comprises forming the porous scaffold reinforcement from one or more wet-laid materials.

61. The method of any one of Claims 51-60, wherein the method further comprises forming the porous scaffold reinforcement from one or more dry laid materials.

62. The method of any one of Claims 51-61, further comprising: heat treating the porous scaffold reinforcement before impregnation; pressure treating the porous scaffold reinforcement before impregnation; or a combination thereof.

63. The method of any one of Claims 51-62, further comprising: plasma treating the porous scaffold reinforcement before impregnation.

64. A fuel cell membrane-electrode assembly, comprising: a) a hydrogen electrode to which hydrogen gas is supplied; b) an oxygen electrode to which an oxidizer gas is supplied; and c) a reinforced ionomeric polymer membrane located between the hydrogen and oxygen electrodes, the reinforced ionomeric polymer membrane being as defined in any one of Claims 1-50.

65. An electrolyzer membrane-electrode assembly, comprising: a) a hydrogen evolution electrode configured for the evolution of hydrogen gas; b) an oxygen evolution electrode configured for the evolution of oxygen gas; and 2296-P9WO -81-c) a reinforced ionomeric polymer membrane located between the hydrogen and oxygen evolution electrodes, the reinforced ionomeric polymer membrane being as defined in any one of Claims 1-50.

66. A hydrogen pump or thermoelectrochemical hydrogen pump membrane- electrode assembly, comprising: a) a hydrogen electrode configured to receive and split hydrogen gas; b) a secondary hydrogen electrode to which protons are transmitted and the hydrogen is reformed; and c) a reinforced ionomeric polymer membrane located between the hydrogen electrode and the secondary hydrogen electrode, the reinforced ionomeric polymer membrane being as defined in any one of Claims 1-50.

67. A method of using the reinforced ionomeric polymer membrane of any one of Claims 1-50 in an electrochemical device such as a fuel cell, electrolyzer, hydrogen pump, thermoelectrochemical hydrogen pump, electrochemical hydrogen compressor, or redox flow battery.

68. The reinforced ionomeric polymer membrane of any one of Claims 1-50, for use in an electrochemical device selected from a fuel cell, electrolyzer, hydrogen pump, thermoelectrochemical hydrogen pump, electrochemical hydrogen compressor, redox flow battery, or other electrochemical device.

69. An electrochemical device comprising the reinforced ionomeric polymer membrane of any one of Claims 1-50, wherein the electrochemical device is a fuel cell, electrolyzer, hydrogen pump, thermoelectrochemical hydrogen pump, electrochemical hydrogen compressor, redox flow battery, or other electrochemical device. 2296-P9WO -82-

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