An object of the present invention is to provide a porous hollow-fiber membrane having high strength while maintaining high pure-water permeation performance. A porous hollow-fiber membrane of the present invention is 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 a molecular chain of the fluororesin-based polymer is oriented in the longitudinal direction of the porous hollow-fiber membrane.

A pervaporation membrane may be an acid-resistant polybenzidimazole (PBI) membrane. The acid-resistant PBI membrane may be a PBI membrane chemically modified by a process selected from the group consisting of sulfonation, phosphonation, cross-linking, N-substitution, and/or combinations thereof. The membrane may be thermally stabilized. A method for the dehydration of an acid material may include the steps of: contacting an acidic aqueous solution with a membrane of an acid-resistant polybenzidimazole; taking away a permeate stream rich in water; and taking away a concentrate steam rich in the acid material. The acidic aqueous solution may be acetic acid.

Disclosed are a copolymer, porous membranes made from the copolymer, and a method of treating fluids to remove metal ions using the porous membranes, for example, from fluids originating in the microelectronics industry, wherein the copolymer includes monomeric units I and II, wherein monomeric unit I is of the formula A-XCH.sub.2B, wherein A is Rf(CH.sub.2)n, Rf is a perfluoro alkyl group of the formula CF.sub.3(CF.sub.2).sub.x, wherein x is 3-12, n is 1-6, X is O or S, and B is vinylphenyl, and monomeric unit II is vinylpyridine.

The present invention addresses the problem of providing: a method for purifying a liquid using a porous polyimide and/or polyamideimide membrane having excellent impurities (e.g., metals) removal performance which is preferably compatible with a flow rate, and also having an excellent stress, an excellent breaking elongation and the like; a method for producing a chemical solution or a cleaning solution employing the purification method; a filter medium comprising the porous membrane; and a filter device equipped with the porous membrane. A method for purifying a liquid, comprising causing a portion or the whole of the liquid to pass through a porous polyimide and/or polyamideimide membrane having communicated pores from one side of the membrane to the other side of the membrane by the action of a differential pressure between the two sides.

An apparatus and method for enhancing the yield and purity of hydrogen when reforming hydrocarbons is disclosed in one embodiment of the invention as including receiving a hydrocarbon feedstock fuel (e.g., methane, vaporized methanol, natural gas, vaporized diesel, etc.) and steam at a reaction zone and reacting the hydrocarbon feedstock fuel and steam in the presence of a catalyst to produce hydrogen gas. The hydrogen gas is selectively removed from the reaction zone while the reaction is occurring by selectively diffusing the hydrogen gas through a porous ceramic membrane. The selective removal of hydrogen changes the equilibrium of the reaction and increases the amount of hydrogen that is extracted from the hydrocarbon feedstock fuel.

A silica membrane filter 10 includes a porous substrate 13 and a silica membrane 18 formed on the porous substrate 13, the silica membrane 18 having an aryl group. The silica membrane 18 has an atomic ratio Si/C, as determined, by elemental analysis using energy-dispersive X-ray spectrometry (EDX), in the range of 0.2 to 15. The silica membrane 18 preferably has a thickness in the range of 30 nm to 300 nm and an X/Y, a ratio of an absorption intensity X of a SiOSi bond to an absorption intensity Y based on the aryl group in a Fourier transform infrared absorption spectrum (FT-IR), in the range of 5.0 to 200.

An apparatus includes a porous substrate and a multi-layer membrane. The porous substrate has a pore structure configured to allow diffusion of hydrogen molecules through the porous substrate. The multi-layer membrane is configured to, in response to contacting a hydrogen molecule present in the gas stream, split the hydrogen molecule into at least one of hydrogen atoms or protons. The multi-layer membrane is configured to allow passage of the hydrogen atoms or protons through the multi-layer membrane while blocking passage of compounds that may be present in the gas stream that are larger than hydrogen molecules. The hydrogen atoms or protons, after passing through the multi-layer membrane, combine to reform the hydrogen molecule. The multi-layer membrane includes a first metallic layer, an intermediate layer, and a second metallic layer.

Water-wettable filtration membranes comprising a microporous sheet of a polyolefin, such as poly(ethylene), grafted with one or more preformed polymers are described. Examples where the preformed polymer is poly(4-ethenylbenzene sulfonic acid) or the poloxamer supplied under the trade name PLURONIC P-123 are provided. The membranes can be used in the recovery or removal of water from aqueous feed streams or the manufacture of composite membranes where a film of hydrophilic poly(ethenol) (polyvinyl alcohol; PVA) is adhered to the microporous sheet. The membranes provide the advantage of being tolerant to the cleaning agents used in clean-in-place protocols and can be used to remove particulates and solutes from these aqueous feed streams. The composite membranes are particularly suitable for use in the recovery or removal of water from feed streams in the beverage and food industries, including dairy.

A method for preparing a nanofiltration membrane and a nanofiltration membrane prepared therefrom, the method comprising the following steps: dissolving a polymer in a solvent to prepare a polymer solution, and curing the polymer solution on a support material to form a base membrane; sequentially applying a first liquid-phase solution and a second liquid-phase solution on the base membrane to form a nascent membrane; densifying the nascent membrane by using a solution that contains an alkaline substance; processing the densified nascent membrane by using a solution that contains an acidic substance; and obtaining the nanofiltration membrane after post-processing and drying.

The present invention relates to a porous ABPBI (phosphoric acid doped poly (2, 5-benzimidazole)) membrane and process of preparing the same. A stable porous ABPBI (Phosphoric Acid Doped Poly (2, 5-benzimidazole)) membrane stable to acids, bases, solvents and autoclaving is disclosed. The membrane finds use for separation of solutes in solution in acids, bases and solvents.