The present disclosure provides composite ion exchange membranes and methods of making the same. The composite ion exchange membranes of the present disclosure include a first layer comprising a first ion-conducting membrane; a second layer comprising a gas-blocking membrane; and a third layer comprising a second ion-conducting membrane.

The present disclosure provides composite ion exchange membranes and methods of making the same. The composite ion exchange membranes of the present disclosure include a first layer comprising a first ion-conducting membrane; a second layer comprising a gas-blocking membrane; and a third layer comprising a second ion-conducting membrane.

Disclosed are polyimide blends and methods of making and using same. The disclosed polyimide blends are prepared by first blending an ionic polymer and a poly(amic acid) to form a poly(amic acid) precursor, followed by cyclization. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

A polymer ion exchange membrane including an ion exchange resin (A) having a basic site density DA and an ion exchange resin (B) having a basic site density DB, wherein a difference (DADB) between the basic site density DA and the basic site density DB is 0.3 mmol/cm.sup.3 or more.

Ion exchange membranes materials according to the present disclosure exhibit improved conductivity at low and intermediate relative humidity without sacrificing mechanical strength. Polymers are provided that include a backbone with one or more aryl groups, a halocarbyl group, and a halocarbyl side chain attached to the backbone, wherein the halocarbyl side chain includes a halide separated from the backbone by a hydrocarbyl chain, a hydrocarbyl ring, or combinations thereof. The halide is substituted with a tertiary amine and halide anions are then exchanged with hydroxide anions. The polymers are then contacted with phosphoric acid, which is deprotonated by the hydroxide ions, forming anions which enhance interactions with adjacent quaternary ammonium groups and induce excess phosphoric acid molecules to cluster around those quaternary ammonium groups. The membranes exhibit negligible dopant leaching even at high relative humidity.

The ion exchange membrane according to the present invention comprises a layer A comprising a fluorine-containing polymer having a sulfonic acid group and a layer B comprising a fluorine-containing polymer having a carboxylic acid group, wherein a ratio of an ion cluster diameter of the layer B after electrolysis under the following electrolysis conditions to the ion cluster diameter of the layer B before the electrolysis [(the ion cluster diameter of the layer B after the electrolysis)/(the ion cluster diameter of the layer B before the electrolysis)] is 0.83 to 0.95: (Electrolysis Conditions) in a zero-gap base electrolytic cell where the ion exchange membrane is disposed between an anode chamber to which a 3.5 N aqueous sodium chloride solution is supplied and a cathode chamber to which a 10.8 N aqueous sodium hydroxide solution is supplied, electrolysis is performed for 7 days under conditions having a temperature of 85 C. and a current density of 6 kA/m.sup.2.

An ion exchange membrane includes a layer S including a fluorine-containing polymer having a sulfonic acid group, a layer C including a fluorine-containing polymer having a carboxylic acid group, and a plurality of strengthening materials arranged inside the layer S and functioning as at least one of reinforcement yarn and sacrifice yarn. A and B satisfy following formulas:

B240 m(1)

2.0B/A5.0(2) wherein, when the ion exchange membrane is viewed from the top surface, A represents an average cross-sectional thickness of the membrane measured in pure water for a region, in which the strengthening materials do not exist, and B represents an average cross-sectional thickness of the membrane measured in pure water for a region, in which strands of the reinforcement yarn overlap with each other, and in a region, in which the reinforcement yarn overlaps with the sacrifice yarn.

A method for producing a laminated complex according to one embodiment of the present invention is a method for producing a laminated complex that includes a sheet-shaped or tube-shaped porous support and a semipermeable membrane layer stacked on an outer surface of the support, the method including a coating step of coating an outer surface of the support with a semipermeable membrane layer-forming composition in which a fluororesin is dispersed in a solvent; an immersing step of immersing the coated surface of the support in water after the coating step; and a heating step of heating water in which the support is immersed.

In order to provide a membrane (100) for a membrane-electrode assembly (MEA) of a fuel cell, comprising two partial membranes (200, 300), which allows for a simpler water circuit compared to the prior art, it is proposed that the partial membranes (200, 300) have different ion exchange capacities (IECs) and/or one partial membrane (200) consists of a perfluorosulfonic acid polymer (PFSA) and the other partial membrane (300) consists of a sulfonated hydrocarbon polymer (HC). Optionally, the membrane can contain a porous carrier film (600). Moreover disclosed are a method for producing the membrane (100) as well as a membrane-electrode assembly and a fuel cell.

The present inventive concept relates to a chemically modified anion exchange membrane and a method of preparing the same and, more particularly, an anion exchange membrane in which sulfonic acid groups in a perfluorinated sulfonic acid electrolyte membrane are substituted with anion conductive groups such as an ammonium group, a phosphonium group, an imidazolium group, a pyridinium group and a sulfonium group, and a method of preparing an anion exchange membrane by chemically modifying sulfonic acid groups in a perfluorinated sulfonic acid electrolyte membrane.