The present invention provides a separation membrane that is usable at a high temperature and a high pressure. The solvent-resistant separation membrane of the present invention has an average pore diameter of the separation membrane surface of 0.005 to 1 ?m and includes a portion where a degree of cyclization (I.sub.1600/I.sub.2240) as measured by the total reflection infrared absorption spectroscopy is 0.5 to 50.

A substrate for a liquid filter that contains a polyolefin microporous membrane, in which a mean flow pore size d.sub.pp in a pore size distribution of the polyolefin microporous membrane measured by a half dry method according to gas-liquid phase substitution is from 1 nm to 20 nm, a mean flow pore size d.sub.LLP in a pore size distribution of the polyolefin microporous membrane measured by a half dry method according to liquid-liquid phase substitution is from 1 nm to 15 nm, a difference (d.sub.pp-d.sub.LLP) between the mean flow pore size d.sub.pp and the mean flow pore size d.sub.LLP is 12 nm or less, and a thickness of the polyolefin microporous membrane is from 4 to 25 ?m.

The present invention relates to a method of preparing a perm-selective porous membrane and a method of separating gases using the prepared porous membrane. According to the present invention, a membrane is synthesized using a hierarchically structured alumina porous support by a counter diffusion method. During this synthesis, the diffusion rate of metal ions loaded on the porous support is controlled by controlling the pore size of the porous support, and the position at which the membrane is synthesized is controlled by synthesizing the membrane inside the support. This can increase the physical stability of the membrane and make the membrane thicker so as to ensure higher H.sub.2/CO.sub.2 separation factors.

In a general aspect, a composite contact composite membrane for direct removal of carbon dioxide from oceanwater is presented. In some cases, a composite membrane includes a supporting layer having a first surface and a second, opposite surface; and a carbon dioxide selective layer disposed on the first surface. The carbon dioxide selective layer is configured to contact an aqueous solution including dissolved carbon dioxide and to selectively transport the dissolved carbon dioxide from the aqueous solution through the supporting layer to the second opposite surface.

The present inventive concept relates to a chemically modified anion exchange membrane and a method of preparing the same and, more particularly, an anion exchange membrane in which sulfonic acid groups in a perfluorinated sulfonic acid electrolyte membrane are substituted with anion conductive groups such as an ammonium group, a phosphonium group, an imidazolium group, a pyridinium group and a sulfonium group, and a method of preparing an anion exchange membrane by chemically modifying sulfonic acid groups in a perfluorinated sulfonic acid electrolyte membrane.

An apparatus for enriching a target gas from a gas mixture. The apparatus includes a cascading series of parallel arrangements of a plurality of gas separator cells. The gas separator cells of a second stage receive the output of gas separator cells of a prior stage as input. A gas separator cell includes an input portion, and a depleted gas outlet that is fed to an input of another gas separator cell or fed back to upstream stages. The outlet of a current stage connects to an input inlet of a subsequent stage. The input and output portions of the gas separator cell connect to form a chamber formed by connection of the input portion and the output portion and which includes a gas permeable membrane, selective to a target gas. The gas separator cell includes a gas permeable material supporting the gas permeable membrane.

The purpose of the present invention is to provide a composite semipermeable membrane having achieved both strength and water-permeable properties. This composite semipermeable membrane is provided with a substrate, a porous support body disposed on the substrate, and a separation function layer provided on the porous support body. The substrate has a structure provided with a crimped portion and a non-crimped portion. The porous support body is impregnated inside a crimped portion and inside a non-crimped portion of the substrate.

Systems and methods for treating a membrane are described. The method includes causing a nanomaterial to contact at least a portion of a wall of at least on channel extending through a membrane, and causing the nanomaterial to adhere to the portion of the wall of the at least one channel. A fluid filtration system is also described. The filtration system includes a housing and a filter membrane. The housing may have a reservoir and a filter compartment. The filter membrane may have a channel extending therethrough. The channel may have a plurality of micropores along a wall thereof. The filter compartment may be configured to receive the filter membrane therein, the filter membrane configured to guide fluid thereacross to remove substances from the fluid or to modify substances in the fluid.

The present specification provides a composition for interfacial polymerization of polyamide including at least one of an amine compound and an acyl halide compound; a surfactant; and a compound represented by Chemical Formula 1, and a method for preparing a reverse osmosis membrane using the same.

Systems and methods are provided for recovering helium from a feed comprising helium, carbon dioxide, and at least one of nitrogen and methane. The feed is separated in a first separator to form helium-enriched stream and a CO.sub.2-enriched stream. The helium-enriched stream is separated in a pressure swing adsorption unit to form a helium-rich product stream and a helium-lean stream. At least a portion of the helium-lean stream is recycled to the first separator with the feed. In some embodiments, a membrane separation unit is used to enhance helium recovery.