A substrate for a composite membrane includes a microporous polyolefin membrane for carrying a hydrophilic resin compound within the pores of the microporous membrane wherein: the average pore diameter is 1 nm to 50 nm; the porosity is 50% to 78%; the membrane thickness is 1 μm to 12 μm; and, when a mixed solution of ethanol and water (volume ratio ½) is dripped onto a surface of the microporous polyolefin membrane which has not undergone hydrophilization treatment, the contact angle θ1 between the droplet and the surface is 0 to 90 degrees 1 second after the dripping, and the contact angle θ2 between the droplet and the surface is 0 to 70 degrees 10 minutes after the dripping, and the rate of change of the contact angle ((θ1−θ2)/θ1×100) is 10 to 50%.

In one exemplary embodiment of the present invention, there are provided a method of hydrophilizing a porous membrane which includes treating a porous membrane with plasma in the presence of a mixed gas containing sulfur dioxide (SO.sub.2) and oxygen (O.sub.2), and a method of preparing an ion-exchange membrane using the same.

The present disclosure is related to a polymeric membrane having a first surface and a second surface and a wall extending between the first and second surface, the membrane comprising pores on the first and second surfaces and throughout the wall, the membrane comprising a modified surface, the modified surface comprising acrylate and/or methacrylate polymers and/or copolymers, wherein the modified surface extends at least over the first and/or the second surface, and over the pores of at least 50% of the thickness of the wall. Furthermore, the present disclosure provides a method for producing such a membrane as well as a use of the membranes as disclosed herein for purification of aqueous media such as in biopharmaceutical applications.

A method is disclosed for forming a microporous membrane that incorporates an additive having low water solubility at the membrane's active surface from a precipitation fluid. The incorporated additive at the membrane's active surface can improve one or more of the membrane's hydrophilicity, wettability, anti-fouling behavior, blood compatibility, and stability over long periods of use or repetitive use. The microporous membrane with this modified active surface can be a hollow fiber, flat sheet, or other self-supporting shape. The microporous membranes can be used for membrane filtering or a solute and/or solvent exchange process, which involve contacting aqueous-based fluid or blood with the microporous membrane, such processes for dialysis, blood oxygenation, or blood separation filtering, or other processes.

The present invention relates to a thin film composite membrane and a manufacturing method therefor. The thin film composite membrane according to the present invention has superior water flux and excellent salt (NaCl) rejection and/or boron rejection.

The present invention relates to an acid-resistant nanomembrane with an improved flow rate and a method of producing the acid-resistant nanomembrane, and more particularly, to an acid-resistant nanomembrane with an improved flow rate, which can also be used under strong-acid and high-temperature conditions for the recovery of rare metals, valuable metals, and the like generated in a smelting process and which exhibits both excellent flow rate and excellent acid resistance, and a method of producing the acid-resistant nanomembrane.

A water-permeable device. The device has a supporting layer and a water-permeable membrane. The water-permeable membrane includes graphene layers that are aligned to form interlayer hydrophobic channels between the graphene layers. The interlayer hydrophobic channels are positioned to be aligned with the direction of water permeation. Also disclosed are systems and methods for water treatment.

A porous membrane containing a hydrophobic polymer and a water-insoluble hydrophilic polymer, the porous membrane having a dense layer in the downstream portion of filtration in the membrane, having a gradient asymmetric structure in which the average pore diameter of fine pores increases from the downstream portion of filtration toward the upstream portion of filtration, and having a gradient index of the average pore diameter from the dense layer to the coarse layer of 0.5 to 12.0.

The present invention relates to an ultrathin-film composite membrane based on a thermally rearranged poly(benzoxazole-imide) copolymer and a production method therefor and to a technique for forming a porous support by means of a thermally rearranged poly(benzoxazole-imide)copolymer and then producing, on the porous support, an ultrathin-film composite membrane comprising a thin-film active layer. The ultrathin-film composite membrane produced according to the present invention has excellent thermal/chemical stability and mechanical physical properties, thus is not only capable of withstanding high operating pressure, but also capable of minimizing internal concentration polarization and thereby obtaining high water permeance and, as a result, high power density, and thus can be applied to a pressure-retarded osmosis or forward osmosis process. Further, said ultrathin-film composite membrane has excellent chemical/thermal stability against organic solvents, has superior organic solvent nano-filtration performance, particularly maintains nano-filtration performance stably even under a high-temperature organic solvent condition, and thus can be applied as an organic solvent nano-filtration membrane.

A porous membrane comprising a membrane-forming polymer (A) and a polymer (B) containing a methyl methacrylate unit and a hydroxyl group-containing (meth)acrylate (b1) unit. A flux of pure water to permeate the porous membrane is preferably 10 (m.sup.3/m.sup.2/MPa/h) or more and less than 200 (m.sup.3/m.sup.2/MPa/h). The contact angle of the bulk of the membrane-forming polymer (A) is preferably 60° or more. The membrane-forming polymer (A) is preferably a fluorine-containing polymer. The polymer (B) is preferably a random copolymer.