A membrane having permselectivity for perchlorate ion is prepared using certain types of quaternary ammonium salts contained in a polymeric matrix material, which may be plasticized. Such membranes are useful in electrodialysis processes, whereby perchlorate-contaminated aqueous compositions are purified.

The present disclosure provides a polymer protecting layer, a lithium metal negative electrode, a lithium secondary battery. In the lithium secondary battery of the present disclosure, a polymer protecting layer comprising a polymer ionic liquid is coated on a surface of a lithium metal sheet, which can effectively slow down or even inhibit the growth of the lithium dendrite, improve the first charge-discharge cycle coulombic efficiency of the lithium secondary battery, and significantly improve the cycle performance and the safety performance of the lithium secondary battery.

An ion exchange membrane obtained by using an ionic monomer having at least two or more polymerizable functional groups, in which a hydrophobicity index H obtained by an expression below from a monomer for forming an ion exchange resin and a material fixed to the resin in the ion exchange membrane is 1.6 or greater, and a manufacturing method therefor. Hydrophobicity index H=Σ{(log P of each component)×(molar ratio of each material in resin)}.

The invention provides: imidazole and imidazolium compounds of formulas (I) and (II): ##STR00001##
polymers containing a plurality of imidazolium-containing repeating units of formula (III′): ##STR00002##
and membranes and devices comprising the polymers. Also provided are methods of making the inventive compounds and polymers.

The present invention relates to the preparation of novel anion exchange membranes from bicomponent or tricomponent copolymers containing both quaternizable and cross-linkable moieties. The bicomponent copolymers consisted with polyacrylonitrile and poly(2-dimethylaminoethyl) methacrylate and the tricomponent copolymers consisted with polyacryloniterle and poly2-dimethylaminoethyl) methacrylate and polyn-butyl acrylate. Quaternization of dimethyl amino groups of copolymer by methyl iodide followed by cross-linking of acrylonitrile groups of copolymer by hydrazine hydrate resulted anion exchange membrane with desired properties such as high ion exchange capacity (1.30-1.50 meqg.sup.−1), high transport number (0.92-0.93) for direct use in electrodyalysis unit. The tricomponent anion exchange membrane containing 32 wt % PDMA, 17 wt % PnBA, and 51 wt % PAN exhibited improved performance mainly in terms of low power consumption and high current efficiency during desalination of water.

Ion exchange membranes may comprise a polymeric microporous substrate and a cross-linked ion transferring polymeric layer on the substrate. The cross-linked ion transferring polymeric layer may comprise a polymerization product of at least a functional monomer and a low value r.sub.2/r.sub.s monomer. The ion exchange membranes may have an apparent permselectivity of at least about 95% and a resistivity of less than about 1.5 Ohm-cm.sup.2.

An electrochemical compressor utilizes an anion conducting layer disposed between an anode and a cathode for transporting a working fluid. The working fluid may include carbon dioxide that is dissolved in water and is partially converted to carbonic acid that is equilibrium with bicarbonate anion. An electrical potential across the anode and cathode creates a pH gradient that drives the bicarbonate anion across the anion conducting layer to the cathode, wherein it is reformed into carbon dioxide. Therefore, carbon dioxide is pumped across the anion conducting layer. The compressor may be part of a refrigeration system that pumps the working fluid in a closed loop through a condenser and an evaporator.

This specification describes an ion exchange membrane and a method of making it. The membrane may be used, for example, in an electrodialysis module or electrochemical cell. The membrane comprises an ion exchange polymer and inorganic particles preferably linked to the ion exchange polymer. To make a membrane, inorganic particles are mixed into an ion exchange membrane pre-cursor. A polymerization initiator or catalyst is then added and the resulting mixture is placed in a form and cured. The inorganic particles may comprise, for example, an oxidized form of graphite such as graphite oxide. The ion exchange polymer may comprise an ionic monomer, containing a quaternary ammonium group for anion exchange or a sulfonate group for cation exchange, along with a crosslinking co-monomer containing polymerizable diacrylic functionalities. The membrane is self-supporting and can be made without a supporting fabric.

A composite containing a fabric and a polyampholyte hydrogel is provided. In the composite, the polyampholyte hydrogel is a hydrogel of a polymer containing randomly dispersed cationic and anionic repeat groups and at least a part of the fabric is coated with the polyampholyte hydrogel. A method of preparation of the composite involves steps (a) to (c): (a) providing a monomer mixture for preparation of a polyampholyte hydrogel; (b) immersing a fabric in the monomer mixture solution; and (c) polymerizing monomers in the monomer mixture solution to obtain a precursor of the composite.

Membranes having an average pore size of 5 nm to 5,000 nm and a porosity of 15% or more, said membrane being obtainable by a process comprising curing a composition comprising: 5 to 64 wt % of (i) a cross-linking agent comprising at least one cationic group; and 36 to 95 wt % of (ii) inert solvent(s).

The membranes are useful for detecting, filtering and/or purifying biomolecules.