The anion exchange membranes exhibit enhanced chemical stability and ion conductivity when compared with traditional styrene-based alkaline anion exchange membranes. A copolymer backbone is polymerized from a reaction medium that includes a diphenylalkylene and an alkadiene. The copolymer includes a plurality of pendant phenyl groups. The diphenyl groups on the polymer backbone are functionalized with one or more haloalkylated precursor substrates. The terminal halide from the precursor substrate can then be substituted with a desired ionic group. The diphenylethylene-based alkaline anion exchange membranes lack the α-hydrogens sharing tertiary carbons with phenyl groups from polystyrene or styrene-based precursor polymers, resulting in higher chemical stability. The ionic groups are also apart from each other by about 3 to 6 carbons in the polymer backbone, enhancing ion conductivity. These membrane are advantageous for use in fuel cells, electrolyzers employing hydrogen, ion separations, etc.

A highly permeable sorbent platform based on polysulfone and polystyrene-b-poly(acrylic acid) composite membranes. The membranes possess a fully interconnected network of poly(acrylic acid)-lined pores, which enables the surface chemistry to be tailored through sequential attachment of polyethyleneimine moieties and metal-binding terpyridine ligands. The polyethyleneimine moieties increase the saturation capacity, while the addition of terpyridine enables high-affinity binding to a diversity of transition metal ions. This membrane platform removes such metal contaminants from solution. The metal capture performance of the functionalized membranes persists even in high concentrations of competitive ions. Also, fluorescence quenching of the terpyridine moiety upon metal ion complexation offers an in-situ probe to monitor the extent of sorbent saturation. The permeability, capacity, and affinity of these membranes, with high-density display of a metal-binding ligand, offer a chemically tailored platform to address the challenges that arise in ensuring clean water.

The anion exchange membranes exhibit enhanced chemical stability and ion conductivity when compared with traditional styrene-based alkaline anion exchange membranes. A copolymer backbone is polymerized from a reaction medium that includes a diphenylalkylene and an alkadiene. The copolymer includes a plurality of pendant phenyl groups. The diphenyl groups on the polymer backbone are functionalized with one or more haloalkylated precursor substrates. The terminal halide from the precursor substrate can then be substituted with a desired ionic group. The diphenylethylene-based alkaline anion exchange membranes lack the α-hydrogens sharing tertiary carbons with phenyl groups from polystyrene or styrene-based precursor polymers, resulting in higher chemical stability. The ionic groups are also apart from each other by about 3 to 6 carbons in the polymer backbone, enhancing ion conductivity. These membrane are advantageous for use in fuel cells, electrolyzers employing hydrogen, ion separations, etc.

An anion exchange membrane is provided by converting carbon-carbon double bonds in the backbone of polystyrene-block-polybutadiene-block-polystyrene (SBS) into epoxide groups. Unmodified SBS is first partially hydrogenated to remove about 65% to about 90% of carbon-carbon double bonds. The remaining double bonds are then converted to epoxide groups to form an epoxidized SBS. UV-initiated ring opening reactions between the epoxidized SBS and haloalkyloxiranes are then employed to simultaneously functionalize and crosslink the epoxidized SBS. The halide groups in the crosslinked polymer network can be replaced via nucleophilic substitution to offer anion conductivity, e.g., via reaction with trimethylamine. Further ion exchange reactions can then be performed to make the membrane hydroxide conductive. The crosslinked membranes described herein exhibit a mechanical strength improvement of 200% compared to unmodified SBS, while maintaining high hydroxide conductivity. This synthetic platform is advantageous to provide mechanically robust anion exchange membranes for fuel cell applications.

Provided is a collection of resin beads,

wherein the resin beads comprise one or more vinyl polymers having quaternary ammonium groups;

wherein cation exchange resin, if present in the collection of resin beads, is present in an amount of 0 to 0.5% by weight based on the weight of the collection of resin beads;

wherein 90 mole % or more of the quaternary ammonium groups are each associated with a hydroxide anion;

wherein sodium, if present, is present in an amount of 0-100 ppb by weight, based on the weight of the collection of resin beads.

In one exemplary embodiment of the present invention, there are provided a method of hydrophilizing a porous membrane which includes treating a porous membrane with plasma in the presence of a mixed gas containing sulfur dioxide (SO.sub.2) and oxygen (O.sub.2), and a method of preparing an ion-exchange membrane using the same.

A polymerizable composition for forming an ion-exchange resin precursor, the polymerizable composition containing a monomer component and polyethylene particles in an amount of 50 to 120 parts by mass per 100 parts by mass of the monomer component, wherein the monomer component contains an aromatic monomer for introducing ion-exchange groups and a nitrogen-containing aliphatic monomer, the nitrogen-containing aliphatic monomer being present in an amount of 10 to 35% by mass in said monomer component. An ion-exchange membrane is produced by applying the polymerizable composition onto a polyolefin type filament base material and polymerizing the polymerizable composition to form an ion-exchange resin precursor and, thereafter, introducing ion-exchange groups into the precursor.

A polymerizable composition for forming an ion-exchange resin precursor, the polymerizable composition containing a monomer component and polyethylene particles in an amount of 50 to 120 parts by mass per 100 parts by mass of the monomer component, wherein the monomer component contains an aromatic monomer for introducing ion-exchange groups and a nitrogen-containing aliphatic monomer, the nitrogen-containing aliphatic monomer being present in an amount of 10 to 35% by mass in said monomer component. An ion-exchange membrane is produced by applying the polymerizable composition onto a polyolefin type filament base material and polymerizing the polymerizable composition to form an ion-exchange resin precursor and, thereafter, introducing ion-exchange groups into the precursor.

A major challenge in the development of anion exchange membranes for fuel cells is the design and synthesis of highly stable (chemically and mechanically) and conducting membranes. Membranes that can endure highly alkaline environments while rapidly transporting hydroxides are desired. A design for using cross-linked polymer membranes is disclosed to produce ionic highways along charge delocalized pyrazolium and homoconjugated triptycenes. The ionic highway membranes show improved performance in key parameters. Specifically, a conductivity of 111.6 mS cm.sup.1 at 80 C. was obtained with a low 7.9% water uptake and 0.91 mmol g.sup.1 ion exchange capacity. In contrast to existing materials, these systems have higher conductivities at reduced hydration and ionic exchange capacities, emphasizing the role of the highway. The membranes retain more than 75% of initial conductivity after 30 days of alkaline stability test. This effective water management through ionic highways is confirmed by density functional theory and Monte Carlo studies. A single cell with platinum group metal catalysts at 80 C. showed a high peak density of 0.73 W cm.sup.2 (0.45 W cm.sup.2 from silver-based cathode) and stable performance during 400 h tests.

A method of manufacturing an anion exchange membrane comprises the following steps: grafting side chains onto a TPE; purifying the grafted TPE; casting the purified grafted TPE; and functionalising the grafted TPE to obtain a cationic moiety. The anion exchange membrane may be used in electrochemical devices including electrolysers, fuel cells or compressors, and is particularly suited to anion exchange membrane electrolysers operating with a dry-cathode.