The present invention deals with a method for obtaining membranes in the form of hollow fibers with application in the field of carbon dioxide removal from natural gas. The aforementioned membranes are obtained by means of heat treatment of polymeric membranes. In this method, polymeric membranes are obtained by a phase-inversion technique by immersion-precipitation and are subsequently subjected to a heat treatment, that is, that the membranes effectively become precursor membranes of the heat treatment. The heat treatment process involves the optimization of the heating rate, temperature, and stabilization time variables, aiming at the improvement of the transport properties of the polymeric membranes. After the heat treatment, it becomes possible to use the membranes in separation processes of gases which operate at pressures greater than 30 bar, with selectivity for carbon dioxide (CO.sub.2).

This invention provides a polymeric separation membrane that has excellent durable antibacterial effect and stain resistance, and a preparation method thereof. The polymeric separation membrane can be widely applied for water treatment, which belongs to the field of water treatment and membrane separation science and technology. The polymeric separation membrane containing quaternary ammonium salt is prepared by the immersion precipitation phase inversion method, using quaternary ammonium salt mixed with polymer and additives. This modification method effectively improves the antibacterial and antifouling ability of the polymeric separation membrane prolongs the service life of membranes and significantly inhibits the reproduction of bacterial and microbial. The preparation method has the advantages of simple process, easy operation, easy for promotion, and also avoids expensive equipment. The polymeric separation membrane has great antibacterial ability and stain resistance, therefore, it has potential application in the field of water treatment.

A separation membrane for blood processing, wherein the separation membrane for blood processing includes: a separation membrane containing polysulfone-based polymer and polyvinylpyrrolidone; and a coating film provided on at least a part of the surface of the separation membrane and containing a polymer material having a structure represented by the following general formula (1):

##STR00001##

wherein R.sup.1 is a hydrogen atom or a methyl group; R.sup.2 is a methyl group or an ethyl group; n is 2 to 6 and m is 1 to 3; P denotes the number of repetition; and a plurality of each of R.sup.1, R.sup.2, n, and m present in one molecule may be the same or different.

One aspect of the present invention concerns a porous hollow fiber membrane containing a vinylidene fluoride-based resin. The hollow fiber membrane has a gradient structure in which a pore diameter of pores in the hollow fiber membrane gradually becomes smaller at least toward one of inner and outer peripheral surface sides and is hydrophilized by containing a crosslinked body of a polyvinylpyrrolidone-based resin.

The purpose of the present invention is to provide a porous membrane that has both high water permeability and excellent protein fractionation performance. Provided is a method for producing a porous membrane, said method comprising a step for discharging a membrane-forming dope that contains a hydrophilic polymer from a slit formed in a mouthpiece, and a step for, after the passage of the discharged membrane-forming dope through a dry part, solidifying the membrane-forming dope in a coagulation bath to give a porous membrane, wherein the cross-section area of the slit is 3-30 times inclusive as large as the cross-section area of the solidified porous membrane.

The present invention provides a separation membrane for blood processing, comprising a polysulfone polymer, a hydrophilic polymer and a polymer having a hydroxy group in a side chain and having a solubility of 0.5 g or less in water (100 g) at 20? C., in which the content of the polymer falls within a specific range, and a blood processing apparatus having the membrane installed therein.

Disclosed herein is a membrane composition. The membrane composition includes: about 8 wt % to less than about 20 wt % of a vinylidene fluoride polymer resin; more than 60 wt % to about 90 wt % of a solvent; about 0.1 wt % to about 5 wt % of an acetylated methyl cellulose; and about 1 wt % to about 15 wt % of a hydrophilic additive.

A membrane, in which the membrane is an ultrapure water membrane; a food and/or beverage processing membrane; a municipal water membrane; a peel oil recovery membrane; a (bio) refinery dewatering membrane; an oily wastewater (pre-)treatment membrane; a metal extraction membrane; a desalination membrane; and/or a protein fraction membrane. The membrane includes a porous substrate layer and an active layer arranged over at least a part of the substrate layer. The active layer is at least partially crosslinked and comprises a superhydrophilic agent. Also described is a method of producing the separation membrane.

The invention relates to a blood treatment device configured to dephosphorylate extracellular adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP) and/or lipopolysaccharide (LPS) in the blood of a patient in need thereof in an extracorporeal blood circuit, wherein the device comprises a matrix having alkaline phosphatase (AP) immobilized thereon. The invention further relates to an extracorporeal blood circuit comprising a blood treatment device of the invention and to the blood treatment device for use as a medicament or to methods of treating an infection, preferably a blood or systemic infection, such as sepsis, and/or for the treatment of sepsis-associated acute kidney injury (AKI).

The disclosure relates to a method for improving the selectivity of a membrane, specifically of a membrane comprising a blend of i) a polysulfone, polyethersulfone or polyarylethersulfone and ii) polyvinylpyrrolidone, characterized in that the membrane is coated with polydopamine and heparin in a one-step or two-step reaction or by in situ modification with polydopamine followed by coating with heparin. The disclosure further relates to a process for producing such modified membranes having an improved selectivity, and to a filtration/diffusion device comprising the membrane which can be used, for example, in hemodialysis applications.