Methods of producing an ion exchange membrane support are disclosed. The methods include saturating a polymeric microporous substrate with a charged monomer solution comprising at least one functional monomer, a cross-linking agent, and an effective amount of at least one photopolymerization initiator and polymerizing the at least one functional monomer by exposing the saturated polymeric microporous substrate to ultraviolet light under conditions effective to cross-link the at least one functional monomer and produce the ion exchange membrane support. Methods of producing a monovalent selective ion exchange membrane are also disclosed. The methods include functionalizing an exterior surface of the ion exchange membrane support with a charged compound layer, drying the ion exchange membrane support and soaking the ion exchange membrane support in a solution comprising an acid or a base for an amount of time effective to produce the monovalent selective ion exchange membrane.

Cationic polymers are provided that comprise monomeric units of Formula (V). (V) Each asterisk (*) indicates an attachment position to another monomeric unit; R is hydrogen or methyl; each R.sup.2 is each independently an alkyl, aryl, or a combination thereof; L is a linking group comprising an alkylene group; and +R.sup.3 is a cationic nitrogen-containing group free of any N—H bonds. Membranes formed from said cationic polymers, devices including such membranes, and methods of making such cationic polymers are also provided.

A single piece-type bipolar film roll with a mesh cloth support and a manufacturing method therefor. The single piece-type bipolar film roll is supported by a high-strength ultra-high molecular weight polyethylene mesh cloth, one side of the single piece-type bipolar film roll is a cation exchange layer containing a benzenesulfonic acid group, the other side of the single piece-type bipolar roll is an anion exchange layer containing a benzyl dimethyl butyl ammonium quaternary amino group, and the middle is a water dissociation catalyst layer containing a benzyl methyl butyl amine tertiary amino group, and the three layers form the single piece-type bipolar film roll. By providing a wider protective film and a narrower spacing film, a dipping and absorbing film roll is polymerized to prepare a composite base film roll which is then subjected to continuous sulfonation to prepare a single-sided sulfonated composite positive film roll, and then the unreacted blank side is sequentially subjected to three-step chemical reactions such as complete chloromethylation, complete tertiary amination and incomplete methylation, so as to prepare a single piece-type bipolar film roll having a compact structure, a clear middle interface, a high mechanical strength and a stable quaternary amino group, and the product qualification rate is high; and the single piece-type bipolar film roll is suitable for a bipolar film electrodialysis engineering application of an organic material-containing system.

The present disclosure describes membrane compositions and methods for preparing membrane compositions. In particular, the methods employ a layer-by-layer approach to membrane preparation. The membrane compositions provide significantly enhanced membrane performance over existing commercial membranes, particularly in terms of permeability and selectivity.

The objective of the present invention is to provide a precision filter which is suitable for filtering a circuit board production process liquid, which is extremely excellent in the resistance to both a strongly acidic cleaning liquid and a strongly alkaline cleaning liquid and which is extremely excellent in the capability of removing an extremely fine foreign substance. Also, the objective of the present invention is to provide a precision filter cartridge which is used for a circuit board production process liquid and which includes the precision filter. Further, the objective of the present invention is to provide a method for producing a circuit board using the process liquid filtered by the precision filter for a circuit board production process liquid or the precision filter cartridge for a circuit board production process liquid. The precision filter to filtrate a process liquid for producing a circuit board according to the present invention is characterized in comprising a tetrafluoroethylene copolymer (I) having an amino group in a side chain.

A method of making a filter, the resulting filter, and a method of using the filter to filter proteins from solution are described. The method includes contacting a porous, polymeric substrate with a transfer liquid comprising a solvent(s) and a charged polymeric solute. The transfer liquid and the polymeric substrate have a Hansen Solubility Parameter (“HSP”) distance of from about 10 to about 35. Contacting the polymeric substrate with the transfer solution causes the polymeric substrate to accept the charged polymeric solute by diffusion transfer, thereby yielding a functionalized filter medium. Removal of the transfer liquid from the polymeric substrate traps the charged polymeric solute on the surface of the polymeric substrate.

The invention relates to porous polymeric cellulose prepared via cellulose crosslinking. The porous polymeric cellulose can be incorporated into membranes and/or hydrogels. In preferred embodiments, the membranes and/or hydrogels can provide high dynamic binding capacity at high flow rates. Membranes and/or hydrogels comprising the porous polymeric cellulose are particularly suitable for filtration, separation, and/or functionalization media.

A composite membrane comprising a supporting membrane that includes polyphenylene oxide and a separation layer that is disposed on one main surface of the supporting membrane, wherein the poiyphenylene oxide is sulfonated on the one main surface of the supporting membrane and the separation layer includes polyvinyl alcohol having an ionic functional group.

There is provided an apparatus for removing fine particles having membranes for removing fine particles in a liquid, wherein a microfiltration membrane or ultrafiltration membrane having a positive charge and a microfiltration membrane or ultrafiltration membrane having a negative charge are arranged in series. There is also provided a method for removing fine particles using the apparatus. Liquids may be passed through the membrane having a negative charge and the membrane having a positive charge in order; thereby, extrafine particles having a particle size of 50 nm or smaller, especially of 10 nm or smaller, in the liquids can be removed highly. The liquid passing may be carried out in the order reverse thereto.

The present disclosure relates to a microporous hollow fiber filter membrane having a large inner diameter and a thin wall. The fiber can be used for sterile filtration of liquids or removal of particles from liquids. The disclosure further relates to a method for producing the membrane and a filter device comprising the membrane.