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.

The invention relates to methods for the synthesis of a thin-film composite membrane, comprising the following steps: a) providing an ultrafiltration porous support membrane, coated at the outer surface with a thin film, synthesized through interfacial polymerisation or interfacial initiation of polymerisation, b) contacting the membrane with a first solution comprising a first monomer, and allowing the solution to impregnate inside the thin film of the membrane, c) discarding the first solution comprising the first monomer, d) contacting the membrane with a second solution comprising a second monomer, and allowing the solution to impregnate inside the thin film of membrane, whereby the second monomer reacts with the first monomer and optionally with reactive groups of the thin film, e) discarding the second solution comprising the second monomer.

The present disclosure relates to a water-treatment separation membrane including: a porous support and a polyamide layer formed on the porous support, wherein the polyamide layer contains an antioxidant having a solubility parameter value of 9 (J/cm.sup.3).sup.1/2 to 22 (J/cm.sup.3).sup.1/2, and a method of manufacturing the same.

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.

The separations membrane system includes a substrate, a microporous layer, and a selective layer. The microporous layer may be disposed over the substrate. The selective layer may be disposed over the microporous layer, thereby sandwiching the microporous layer between the selective layer and the substrate. The microporous layer includes a thermoplastic material. The selective layer includes a polyamide structure of 2,2-Dimethyl-1,3-propanediamine and/or 1,3,5-Benzenetricarbonyl chloride.

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.

Mesoporous membranes have shown promising separation performance with a potential to lower the energy consumption, leading to a dramatic cost reduction. Recently, an extensive effort has been made on the design of membranes which brought a significant progress toward the synthesis of well-defined porous morphologies, most of which synthesized by surfactant-template methodology. Currently, the most well-designed state-of-the-art membranes using this technique are made from metals, polymers, carbon, silica, etc. In the present invention, we demonstrate mesoporous calcium-silicate particles having superior separation capacity and optimal permeability, thereby leading to reduced energy consumption for selective separation of gases/liquids and/or the combination thereof. We explore various methods to improve the calcium-silicate membranes properties by tuning pore density during the synthesis/aging process, while favoring the formation of uniformly distributed nanopores. Lowering particle density by controlling calcium to silicon ratio along with optimizing the surface area are essential in achieving our objective.

Porous filters having uniform pore size and close packing density are described, along with methods and apparatus for making the porous filters based on nanopatterning. One method includes applying a polymeric liquid to a mold consisting of an array of posts having a desired pore size and distribution. Solidification of polymeric membrane followed by separation from the mold produces a polymer membrane with a predetermined spaced array of pores. A pre-filter film can also be bonded with the membrane during formation to provide increased mechanical support and filtration of larger particles on the input side of the filter. Other process variants are described, including methods for incorporating additional functionalities to the filter.

A porous membrane material comprising a porous membrane substrate coated with a thin, uniform coating of a metal or metal alloy. The membrane material can have high electrical conductivity. The membrane material can exhibit a very high ratio of electrical conductivity to thermal conductivity. The porous membrane substrate may be removed to form the membrane.

The present invention generally relates to polymeric membrane materials formed, at least in part, from monomeric material selected from 2,3,3,3-tetrafluoropropene (CF.sub.3CF═CH.sub.2, HFO-1234yf) or trans-1,3,3,3-tetrafluoropropene (CF.sub.3CH═CFH, HFO-1234ze), and to membrane preparations and uses thereof in water desalination, filtration, membrane distillation, pervaporation, and selective gas separation.