A forward osmosis membrane for seawater desalination and a method for preparing the same. The forward osmosis membrane has a composite membrane structure including a nonwoven fabric layer; a hydrophilic polymer layer; and a polyamide layer. The hydrophilic polymer layer formed on the nonwoven fabric layer facilitates an inflow of water from the feed water to the draw solution to enhance flux and realize high water permeability in the direction of osmosis. The polyamide layer not only secures contamination resistance and chemical resistance but also minimizes the back diffusion of salts of the draw solution in the direction of reverse osmosis. Hence, the forward osmosis membrane of the present invention is greatly useful for desalination of high-concentration seawater.

The present invention provides a porous hollow fiber filtration membrane comprising a polysulfone-based polymer and hydrophilic polymer, the porous hollow fiber filtration membrane including a gradient asymmetric structure in which the average pore diameter of fine pores increases from the outer surface toward the inner surface, a content of the hydrophilic polymer in the membrane is 6.0 to 12.0% by mass, and a ratio of the content of the hydrophilic polymer in the outer surface to the content of the hydrophilic polymer in the membrane is 1.20 to 1.60.

A chromatography device having a housing having an inlet and an outlet. At least two layers of media disposed between the inlet and the outlet inside of the housing forming a media stack, with at least one of the layers comprising a functionalized layer. An optional spacer ring disposed between the two layers of media forming an air gap between them. A non-functionalized sealing layer disposed between the inlet and the outlet inside of the housing as the last layer of media in the media stack within the housing as a fluid passes from the inlet to the outlet through the media stack. A margin of the sealing layer in contact with the housing; the margin being compressed by the housing forming a compressive seal to prevent fluid from leaking to the outlet past the compressive seal.

Disclosed is the preparation of composite membranes formed by a tailored selective chemical modification of an ultra-thin nanoporous surface layer of a semi-crystalline mesoporous poly (aryl ether ketone) membrane with graded density pore structure. The composite separation layer is synthesized in situ on the poly (aryl ether ketone) substrate surface and is covalently linked to the surface of the semi-crystalline mesoporous poly (aryl ether ketone) membrane. Hollow fiber configuration is the preferred embodiment of forming the functionalized the poly (aryl ether ketone) membranes. Composite poly (aryl ether ketone) membranes of the present invention are particularly useful for a broad range of fluid separation applications, including organic solvent ultrafiltration and nanofiltration to separate and recover active pharmaceutical ingredients.

A gas separation membrane has a gas separation layer containing a crosslinked cellulose resin. The crosslinked cellulose resin has a particular linking structure in a crosslinked structure. The gas separation layer contains an organic solvent in a particular amount.

A gas separation asymmetric membrane includes a porous layer having gas permeability; and a compact layer having gas separation capability which is formed on the porous layer in which the gas separation asymmetric membrane is formed using a polyimide compound which has a structural unit represented by Formula (I) and at least one structural unit selected from a structural unit represented by Formula (II) or a structural unit represented by Formula (III) and in which the viscosity, at 25° C., of a solution obtained by dissolving the polyimide compound in N-methylpyrrolidone at a concentration of 5% by mass is in a range of 2.2 to 22.0 mPa.Math.sec,

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in the formula, X.sup.1 represents a group having a structure represented by Formula (I-a) or (I-b).

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The invention is an improved method of making an improved carbon molecular sieve (CMS) membrane in which a precursor polymer (e.g., polyimide) is pyrolyzed at a pyrolysis temperature to form a CMS membrane that is cooled to ambient temperature (about 40° C. or 30° C. to about 20° C.). The CMS membrane is then reheated to a reheating temperature of at least 250° C. to 400° C. to form the improved CMS membrane. The CMS have a novel microstructure as determined by Raman spectroscopy. The improved CMS membranes have shown an improved combination of selectivity and permeance as well as stability for separating light hydrocarbon gas molecules such as C.sub.1 to C.sub.6 hydrocarbon gases (e.g., methane, ethane, propane, ethylene, propylene, butane, butylene).

The present invention provides a semipermeable membrane which has resistance to oxidizing agents even in the presence of heavy metals and which, despite this, can have salt-removing performance equal to that of semipermeable membranes having poor resistance to oxidizing agents. A coated semipermeable membrane of the invention includes a semipermeable layer and a polymer layer formed on the semipermeable layer, and the polymer layer includes a polymerization product formed by both condensation of hydrolyzable groups possessed by the following compound (A) and polymerization of the compound (A) with the following compound (B): (A) a silicon compound having a silicon atom, a reactive group including an ethylenically unsaturated group directly bonded to the silicon atom, and a hydrolyzable group directly bonded to the silicon atom; and (B) a compound other than the compound (A), which has both a hydrophilic group and an ethylenically unsaturated group.

Improved methods for the manufacture of pharmaceutical compositions comprising at least one surfactant, involving prefiltration of the surfactant prior to formulation into final products.

A hollow-fiber membrane according to an aspect of the present disclosure includes a porous, tubular filtration layer containing polytetrafluoroethylene as a main component and having a fibrous skeleton. A mean pore diameter in an outer peripheral surface of the filtration layer is smaller than a mean pore diameter in an inner peripheral surface of the filtration layer. A ratio of the mean pore diameter in the inner peripheral surface to the mean pore diameter in the outer peripheral surface is 2.0 or more and 5.0 or less.