A conductive nanoporous membrane system has a first ion exchange membrane formed from a nanoporous substrate that is coated with a metal or carbon or conductive polymers to form a conductive membrane, a second ion exchange membrane that is also formed from a nanoporous substrate coated with a metal to form a conductive membrane is positioned in spaced relation to the first conductive membrane and coupled to a voltage source; the negatively potential membrane acts as a cation exchange membrane in the presence of an electrolyte, and the positively connected electrode behave as anodic exchange membrane in the presence of an electrolyte due to the formation of electrical double layers at the interface between metal and liquid electrolyte.

An ion exchange membrane (52) for a fuel cell comprises a polymer having an acid functional group normally including protons, and having alkali metal ions partially ion-exchanged with the protons of the acid functional group of the membrane. The partial ion exchange of alkali metal ions into the membrane relates either to patterning of the exchanged ion make-up of the membrane, with some being ion exchanged and some not, or to the extent or concentration of the ion exchange in any particular location, or to both.

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.

A polysulfone membrane is modified so that monomers are wafted onto the surface of the membrane. The polysulfone membranes can be grafted by contacting the membrane with a grafting solution and exposing the membrane to electromagnetic radiation, typically within the ultraviolet portion of the spectrum. The monomers that are grafted are typically anionic or cationic. The grafted membranes can be used for filtering impurities, such as positively and negatively charged particles, from a liquid. Anionic membranes provide improved filtration of negatively charged impurities, while cationic membranes provide improved filtration of positively charged impurities.

The electrochemical energy conversion system of the present disclosure includes an anode, a cathode, and an ion exchange membrane including a polymer having an aromatic polymer chain and an alkylated substrate including an alkyl chain, and at least one ionic group. The alkylated substrate is bound to at least one aromatic group in the polymer chain via Friedel-Crafts alkylation of the at least one aromatic group. The alkylation reaction utilizes a haloalkylated tertiary alcohol or a haloalkylated alkene as a precursor. In the presence of an acid catalyst, a carbocation is generated in the precursor which reacts with the aromatic rings of the polymer chain. The at least one ionic group is then replaced with a desired cationic or anionic group using a substitution reaction. The membranes exhibit advantageous stability achieved through a simplified and scalable reaction scheme.

The present invention relates generally to regeneration of weak base anion exchange resins and more particularly to regeneration using low concentrations of sodium hydroxide and/or sodium carbonate to remove ionic contaminants from the resins.

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.

Dye-sensitized ion-pumping membranes and methods of preparing said membranes are described herein. A regenerative and reversible photoactive dye is covalently-bonded to membrane or separator for ion-pumping. The photoactive dye-functionalized membranes can be arranged with other ion-exchange membranes, which serve as selective contacts to afford photovoltaic action and therefore form a power-producing membrane that pumps ions for use in driving an ion-exchange or ion-transport process, such as desalination and electrodialysis.

A cation exchange chromatographic matrix comprising a base material, and a copolymer with one monomer unit having at least a sulfonic acid group, the copolymer being immobilized on the base material, wherein: the copolymer forms substantially no cross-linked structure, and the copolymer comprises neither acrylamide nor an acrylamide derivative as a monomer unit, or comprises acrylamide or an acrylamide derivative as a monomer unit in a range which has no substantial influence; the ratio of the mass of the copolymer to the mass of the base material is 5% or more and 200% or less; and the density of the sulfonic acid group is higher than 30 mmol/L and 200 mmol/L or lower.

Described herein are crosslinked alkylated poly(benzimidazole) and poly(imidazole) polymer materials and devices (e.g., fuel cells, water electrolyzers) including these polymer materials. The polymer materials can be prepared in a convenient manner, allowing for applications such as anion exchange membranes (AEMs). The membranes provide high anion conductivities over a wider range of operating conditions when compared to the analogous membranes that are not cross-linked. The crosslinked polymer materials have improved alkaline stability, when compared to the analogous non-crosslinked polymer materials.