A process for preparing a hollow fiber includes the steps of providing a dope solution including polyamide imide (PAI), providing an aqueous bore solution including polyethylene imine (PEI), extruding the dope solution in an cross-sectional annular shape and ejecting the bore solution in the center of the annular shape, allowing the PAI and the PEI to react, thereby forming an internal surface layer including the cross-linked reaction product, and forming a polyamide Thin Film Composite (TFC) layer by interfacial reaction of aqueous di- or triamine compound and organic di- or triacylhalide compound on the internal surface layer including the cross-linked reaction product.

A process for preparing a hollow fiber includes the steps of providing a dope solution including polyamide imide (PAI), providing an aqueous bore solution including polyethylene imine (PEI), extruding the dope solution in an cross-sectional annular shape and ejecting the bore solution in the center of the annular shape, allowing the PAI and the PEI to react, thereby forming an internal surface layer including the cross-linked reaction product, and forming a polyamide Thin Film Composite (TFC) layer by interfacial reaction of aqueous di- or triamine compound and organic di- or triacylhalide compound on the internal surface layer including the cross-linked reaction product.

A battery and a method of fabricating a porous membrane are disclosed. The battery includes an anode, a cathode, and a battery separator. The battery separator is positioned between the anode and the cathode and includes a macroporous substrate and a mesoporous silica thin film (MSTF) with perpendicular mesopore channels. The MSTF is positioned on the macroporous substrate. The method includes the following steps. A polymer film is formed on a macroporous substrate. A MSTF with perpendicular mesopore channels is grown on the polymer film. The polymer film is removed to form the porous membrane.

A battery and a method of fabricating a porous membrane are disclosed. The battery includes an anode, a cathode, and a battery separator. The battery separator is positioned between the anode and the cathode and includes a macroporous substrate and a mesoporous silica thin film (MSTF) with perpendicular mesopore channels. The MSTF is positioned on the macroporous substrate. The method includes the following steps. A polymer film is formed on a macroporous substrate. A MSTF with perpendicular mesopore channels is grown on the polymer film. The polymer film is removed to form the porous membrane.

An ionically conductive thin film composite (TFC) membrane is described. The low cost, high performance TFC membrane comprises a micropous support membrane, and a hydrophilic ionomeric polymer coating layer on a surface of the microporous support membrane. The hydrophilic ionomeric polymer coating layer is ionically conductive. The ionomeric polymer can also be present in the micropores of the support membrane. Methods of making the membrane and redox flow battery system incorporating the TFC membrane are also described.

A method for manufacturing a porous film includes: a first step of preparing droplets (D) which are formed from a first liquid into spheres with a predetermined diameter of 10 μm or more and 2000 μm or less and a second liquid (L2) which includes a curing agent which cures by imparting energy or a curing agent which cures due to change in pH and includes droplets dispersed therein; a second step of injecting the droplets and the second liquid into a gap between a pair of substrates (31 and 32); a third step of curing the second liquid to form an external phase; and the fourth step of removing the droplets in the external phase to form hole sections.

A method for manufacturing a porous film includes: a first step of preparing droplets (D) which are formed from a first liquid into spheres with a predetermined diameter of 10 μm or more and 2000 μm or less and a second liquid (L2) which includes a curing agent which cures by imparting energy or a curing agent which cures due to change in pH and includes droplets dispersed therein; a second step of injecting the droplets and the second liquid into a gap between a pair of substrates (31 and 32); a third step of curing the second liquid to form an external phase; and the fourth step of removing the droplets in the external phase to form hole sections.

A crosslinkable copolymer is provided. The crosslinkable copolymer has pendant cationic nitrogen-containing groups with some, but not all, of these pendant groups further including a (meth)acryloyl group. The (meth)acryloyl groups can react to form a crosslinked copolymer that is ionically conductive. The crosslinked copolymer can be used to provide an anion exchange membrane that can be used in electrochemical cells such as fuel cells, electrolyzers, batteries, and electrodialysis cells.

A novel fibrous membrane comprises at least one substrate layer comprising at least 80% by weight of microfibers that carry positively charged and/or negatively charged functional groups, and at least one layer of filtration material attached to the substrate layer, wherein the layer of filtration material comprises at least 80% by weight of nanofibers that carry negatively charged and/or positively charged functional groups. The fibrous membrane is able to remove or reduce the concentration of bacteria, viruses and heavy metals while maintaining relatively high water flow. A filter comprising the fibrous membrane and a method for manufacturing the fibrous membrane are also provided.

A novel fibrous membrane comprises at least one substrate layer comprising at least 80% by weight of microfibers that carry positively charged and/or negatively charged functional groups, and at least one layer of filtration material attached to the substrate layer, wherein the layer of filtration material comprises at least 80% by weight of nanofibers that carry negatively charged and/or positively charged functional groups. The fibrous membrane is able to remove or reduce the concentration of bacteria, viruses and heavy metals while maintaining relatively high water flow. A filter comprising the fibrous membrane and a method for manufacturing the fibrous membrane are also provided.