In one embodiment, a separation membrane includes: a porous support structure; and at least one alkali metal hydroxide disposed within pores of the porous support structure. In another embodiment, a method for separating acidic gases from a gas mixture includes exposing the gas mixture to a separation membrane at an elevated temperature, where the separation membrane includes a porous support and at least one molten alkali metal hydroxide disposed within pores of the porous support.

[Problem] To provide a membrane for the forward osmosis method, which keeps a high porosity, reduces concentration polarization by appropriately controlling the pore distribution, achieves both high water permeability and a self-supporting property, and has high chemical durability such that the membrane is applicable to various draw solutions. [Solution] A separation membrane having a structure inclined from an outer surface side to an inner surface side, a ratio between a thickness of a dense layer having a dense polymer density and a thickness of a coarse layer having a coarse polymer density being in a range of 0.25≦(the thickness of the coarse layer)/[(the thickness of the dense layer)+(the thickness of the coarse layer)]≦0.6, when measuring polymer density distribution in a thickness direction of the separation membrane by Raman spectroscopy.

Some embodiments comprise membranes comprising a first layer comprising a porous graphene-based material; a second layer comprising a porous graphene-based material; a channel positioned between the first layer and the second layer, wherein the channel has a tunable channel diameter; and at least one spacer substance positioned in the channel, wherein the spacer substance is responsive to the environmental stimulus. In some cases, the membranes have more than two layers of porous graphene-based material. Permeability of a membrane can be altered by exposing the membrane to an environmental stimulus. Membranes can be used in methods of water filtration, immune-isolation, timed drug release (e.g., sustained or delayed release), hemodialysis, or hemofiltration.

The present disclosure relates to semipermeable membranes which are suitable for blood purification, e.g. by hemodialysis, which have an increased ability to remove larger molecules while at the same time effectively retaining albumin. The membranes are characterized by a molecular retention onset (MWRO) of between 9.0 kD and 14.5 kD and a molecular weight cut-off (MWCO) of between 55 kD and 130 kD as determined by dextran sieving curves and can be prepared by industrially feasible processes excluding a treatment with salt before drying. The invention therefore also relates to a process for the production of the membranes and to their use in medical applications.

A composite oxygen ion transport membrane having a dense layer, a porous support layer, an optional intermediate porous layer located between the porous support layer and the dense layer and an optional surface exchange layer, overlying the dense layer. The dense layer has electronic and ionic phases. The ionic phase is composed of scandia doped, yttrium or cerium stabilized zirconia. The electronic phase is composed of a metallic oxide containing lanthanum, strontium, chromium, iron and cobalt. The porous support layer is composed of zirconia partially stabilized with yttrium, scandium, aluminum or cerium or mixtures thereof. The intermediate porous layer, if used, contains the same ionic and electronic phases as the dense layer. The surface exchange layer is formed of an electronic phase of a metallic oxide of lanthanum and strontium that also contains chromium, iron and cobalt and an ionic phase of scandia doped zirconia stabilized with yttrium or cerium.

In order to provide a hydrogen purification device in which a source gas is supplied, from which a purified gas flows out, that is easily manufacturable, and in which the pressure resistance of an hydrogen permeable membrane is high, the hydrogen purification device is configured to include a hydrogen permeable membrane allowing hydrogen to selectively permeate therethrough, two porous supports that sandwich and support the hydrogen permeable membrane from both surfaces thereof, and a casing having a space formed therein configured to accommodate reaction of the source gas and the hydrogen permeable membrane. The porous supports are contained inside the casing, an outermost edge of the hydrogen permeable membrane extends outward from the outer edges of the porous supports in at least one location, and a peripheral portion of the hydrogen permeable membrane in a vicinity of the outermost edge and the casing are airtightly sealed to each other.

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 0.1≦X≦0.9. 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 0.1≦X≦0.9. 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.

A thin film composite membrane (TFC) includes an active layer on a support. The active layer includes at least 8 barrier layers of star-polymers each having at least three linear polymers attached at a central core. Each of the barrier layers has a thickness between 5 and 50 nm, and the barrier layers have alternating charge.

The purpose of the present invention is to provide: a thin composite semipermeable membrane having a practical salt rejection and permeation flux; a method for producing said membrane; and a spiral wound separation membrane element that has a practical salt rejection and provides excellent water treatment efficiency. The method for producing the composite semipermeable membrane includes a step in while, while feeding out a porous support having a porous polymer layer on one surface of a nonwoven fabric layer from a supply roll, an amine solution containing a multifunctional amine component is brought into contact with the porous support, and an organic solution containing a multifunctional acid halide component is brought into contact with the amine solution on the porous support to cause interfacial polymerization, thus forming a skin layer containing a polyamide resin on the surface of the porous support.