The present invention relates to a continuous process for preparing permselective hollow fiber membranes being suitable e.g. for hemodialysis, hemodiafiltration and hemofiltration of blood which comprises a two-stage drying and tempering treatment of the hollow fiber membranes. According to a further aspect, the invention relates to a continuous process for drying permselective hollow fiber membranes on-line. The invention also relates to devices for on-line drying of permselective hollow fiber membranes.

A low cost, high selectivity asymmetric polyimide/polyethersulfone (PES) blend hollow fiber membrane, a method of making the membrane and its use for a variety of liquid, gas, and vapor separations such as deep desulfurization of gasoline and diesel fuels, ethanol/water separations, pervaporation dehydration of aqueous/organic mixtures, CO.sub.2/CH.sub.4, CO.sub.2/N.sub.2, H.sub.2/CH.sub.4, He/CH.sub.4, O.sub.2/N.sub.2, H.sub.2S/CH.sub.4, olefin/paraffin, iso/normal paraffins separations, and other light gas mixture separations. The polyimide/PES blend hollow fiber membrane is fabricated from a blend of a polyimide polymer and PES and showed surprisingly unique gas separation property with higher selectivities than either the polyimide hollow fiber membrane without PES polymer or the PES hollow fiber membrane without PES polymer for gas separations such as for H.sub.2/CH.sub.4, He/CH.sub.4, H.sub.2S/CH.sub.4, CO.sub.2/CH.sub.4 separations.

An object of the present invention is to provide a nanofiltration membrane having a molecular weight cut-off of 200 to 1,000 and a high amount pf permeate for methanol, and suitable for use as an organic solvent nanofiltration membrane. A nanofiltration membrane formed using a polyamide resin, the nanofiltration membrane having a molecular weight cut-off of 200 to 1,000 and a methanol permeability of 0.03 L/(m.sup.2.Math.bar.Math.h) or more.

Disclosed are compositions that may be useful for forming synthetic membranes, methods of forming membranes therefrom, and membranes. In an embodiment, a membrane comprises a free hydrophilic polymer and a polyurethane, the polyurethane comprising a backbone comprising the reaction product of a diisocyanate, a polymeric aliphatic diol, and, optionally, a chain extender, wherein the backbone comprises a C.sub.2-C.sub.16 fluoroalkyl or C.sub.2-C.sub.16 fluoroalkyl ether, or the polyurethane comprises an endgroup comprising a C.sub.2-C.sub.16 fluoroalkyl or C.sub.2-C.sub.16 fluoroalkyl ether.

The present invention relates to cellulose based papers coated with nitrocellulose as well as to methods for producing such coated papers and methods for using them, especially in lateral flow applications.

The invention relates to an apparatus and a method for the manufacture of at least one hollow fiber membrane, wherein a spinning mass is extruded via a spinning unit to form a spinning thread and precipitated in a precipitation bath to form a hollow fiber membrane and the hollow fiber membrane is optionally rinsed in a rinsing bath, wherein furthermore the hollow fiber membrane is passed through at least one drying unit, wherein the drying unit comprises a pressure section which is constructed in such a way that a positive pressure compared with atmospheric pressure can be set in the pressure section, and at least part of the precipitating agent or rinsing agent contained in the at least one hollow fiber membrane (104) is separated from the at least one hollow fiber membrane.

The present invention relates to a reverse osmosis membrane and a method of preparing the same, and more particularly to a high durability reverse osmosis membrane which is excellent in interlayer bonding in a separation membrane while maintaining an equal flow rate as compared with a conventional reverse osmosis membrane to minimize a reduction in durability in the membrane upon backwashing to enhance a cleaning effect, prolong the life of a highpressure membrane, maximize the amount of accumulated treated water, and reduce maintenance costs, and a method of preparing the same.

Articles including poly(2,2,3,3,4,4,4-heptafluorobutyl methacrylate) or poly(2,2,3,3,4,4,4-heptafluorobutyl acrylate), fluoropolymers that do not form perfluorooctanoic acid (PFOA) when they degrade and that exhibit unexpectedly good oil repellency, are described. A method of making a fluoropolymer-containing article includes depositing a fluoropolymer-liquid mixture onto porous filtration medium by contacting the porous filtration medium with a mixture comprising a fluoropolymer and a liquid to form the treated porous filtration medium; and removing the liquid. The fluoropolymer includes poly(2,2,3,3,4,4,4-heptafluorobutyl methacrylate) or poly(2,2,3,3,4,4,4-heptafluorobutyl acrylate). Methods of using the article are further described.

This disclosure relates to CO.sub.2-philic crosslinked polyethylene glycol membranes useful for natural gas purification processes. Also provided are methods of using the membranes to remove CO.sub.2 and H.sub.2S from natural gas.

The present invention discloses a nanofiltration composite membrane, a preparation method and application thereof. The preparation method comprises: A) preparing 2D nano-material dispersion; B) first preparing a solution of a polymer material with a certain concentration, continuously adding a poor solvent under stirring conditions to subject the polymer material to chemical reaction to obtain a dispersion containing negatively charged polymer gel particles; C) subjecting the nano-material dispersion in step A) and the dispersion prepared in step B) to blending, membrane preparation and drying, and then placing the membrane into an alkaline solution with a certain concentration and pure water for soaking to obtain a nanofiltration composite membrane. The nanofiltration composite membrane can efficiently remove heavy metal complex ions through the synergistic effect of pore size screening and charge repulsion. Moreover, the rejection rate and flux of the nanofiltration composite membrane have not changed obviously after use for a long time.