An object of the present invention is to provide a porous hollow-fiber membrane satisfying both high strength and high pure-water permeation performance and at the same time, having high bending resistance. The present invention relates to a porous hollow-fiber membrane including a fluororesin-based polymer, in which the porous hollow-fiber membrane has a columnar texture oriented in a longitudinal direction of the porous hollow-fiber membrane and when a photograph of a cross-section parallel to the longitudinal direction of the porous hollow-fiber membrane is binarized into a structure portion and a void portion, the following 1) and 2) are satisfied: 1) a proportion of an area of the void portion is from 20 to 50%, and 2) a value obtained by dividing a total of peripheral lengths of the void portions by a total of areas of the void portions is 2.0 m.sup.1 or less.

The invention relates to carbon supported crack- and tear-free graphene membranes of large area useful for selective gas separation, method of preparation and uses thereof. In particular, the invention relates to carbon supported crack- and tear-free graphene membranes having good gas separation performance, in particular high H.sub.2 permeance and H.sub.2/CH.sub.4 selectivities.

A manufacturing method for an acidic gas separation membrane sheet includes: a step of preparing a hydrophilic resin composition liquid for forming a hydrophilic resin composition layer; a step of removing bubbles contained in the hydrophilic resin composition liquid; a step of applying the hydrophilic resin composition liquid onto a first porous layer to form an applied layer on the first porous layer; and a step of laminating a second porous layer on the applied layer to form a laminated body. The step of removing bubbles includes: a step of applying a shear to the hydrophilic resin composition liquid; and a step of leaving the hydrophilic resin composition liquid.

A polyvinylidene fluoride (PVDF) casting membrane solution is shaped as a flat sheet membrane by thermally induced phase separation (TIPS), the PVDF membrane is defluorinated with an alkaline potassium permanganate solution, and then the carbon chain is extended with glycidyl methacrylate (GMA) as the graft monomer, and finally the nucleophilic substitution is carried out between melamine and GMA to produce a chelating microfiltration membrane for capturing and enriching heavy metals with high flux and high capacity.

A preparation method of separation membrane is provided. First, a polyimide composition including a dissolvable polyimide, a crosslinking agent, and a solvent is provided. The dissolvable polyimide is represented by formula 1:

##STR00001## wherein B is a tetravalent organic group derived from a tetracarboxylic dianhydride containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group and carboxylic acid group, and 0.1X0.9. The crosslinking agent is an aziridine crosslinking agent, an isocyanate crosslinking agent, an epoxy crosslinking agent, a diamine crosslinking agent, or a triamine crosslinking agent. A crosslinking process is performed on the polyimide composition. The polyimide composition which has been subjected to the crosslinking process is coated on a substrate to form a polyimide membrane. A dry phase inversion process is performed on the polyimide membrane.

A preparation method of separation membrane is provided. First, a polyimide composition including a dissolvable polyimide, a crosslinking agent, and a solvent is provided. The dissolvable polyimide is represented by formula 1: ##STR00001## wherein B is a tetravalent organic group derived from a tetracarboxylic dianhydride containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group and carboxylic acid group, and 0.1X0.9. The crosslinking agent is an aziridine crosslinking agent, an isocyanate crosslinking agent, an epoxy crosslinking agent, a diamine crosslinking agent, or a triamine crosslinking agent. A crosslinking process is performed on the polyimide composition. The polyimide composition which has been subjected to the crosslinking process is coated on a substrate to form a polyimide membrane. A dry phase inversion process is performed on the polyimide membrane.

A preparation method of separation membrane is provided. First, a polyimide composition including a dissolvable polyimide, a crosslinking agent and a solvent is provided. The dissolvable polyimide is represented by formula 1:

##STR00001##

wherein B is a tetravalent organic group derived from a tetracarboxylic dianhydride containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group and carboxylic acid group, and 0.1X0.9. The crosslinking agent is an aziridine crosslinking agent, an isocyanate crosslinking agent, an epoxy crosslinking agent, a diamine crosslinking agent, or a triamine crosslinking agent. A crosslinking process is performed on the polyimide composition. The polyimide composition which has been subjected to the crosslinking process is coated on a substrate to form a polyimide membrane. A wet phase inversion process is performed on the polyimide membrane.

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.

Multi-block isoporous structures for non-aqueous and/or harsh chemical media having at least one of high separation specificity, chemical resistance, and antifouling properties, methods of manufacturing and use, for replacements or alternatives to existing separation membrane technologies.

A preparation method of separation membrane is provided. First, a polyimide composition including a dissolvable polyimide, a crosslinking agent and a solvent is provided. The dissolvable polyimide is represented by formula 1: ##STR00001## wherein B is a tetravalent organic group derived from a tetracarboxylic dianhydride containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group and carboxylic acid group, and 0.1X0.9. The crosslinking agent is an aziridine crosslinking agent, an isocyanate crosslinking agent, an epoxy crosslinking agent, a diamine crosslinking agent, or a triamine crosslinking agent. A crosslinking process is performed on the polyimide composition. The polyimide composition which has been subjected to the crosslinking process is coated on a substrate to form a polyimide membrane. A wet phase inversion process is performed on the polyimide membrane.