A separation membrane (10) of the present disclosure includes: a separation functional layer (30) composed of a polyamide containing, as a monomer unit, at least one selected from the group consisting of piperazine and a piperazine derivative; and a coating (40) covering the separation functional layer (30) and containing a polymer having a repeating unit represented by the following formula (1). In the formula (1), N.sup.+ is a nitrogen atom constituting a quaternary ammonium cation, and R.sup.1 and R.sup.2 are each independently a substituent containing a carbon atom bonded to the nitrogen atom.

##STR00001##

A separation membrane (10) of the present disclosure includes: a separation functional layer (30) composed of a polyamide containing, as a monomer unit, at least one selected from the group consisting of piperazine and a piperazine derivative; and a coating (40) covering the separation functional layer (30) and containing a polymer having a repeating unit represented by the following formula (1). In the formula (1), N.sup.+ is a nitrogen atom constituting a quaternary ammonium cation, and R.sup.1 and R.sup.2 are each independently a substituent containing a carbon atom bonded to the nitrogen atom.

##STR00001##

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.

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 comprising a polyoxazoline, and a polyurethane, the polyurethane comprising a backbone comprising the reaction product of a diisocyanate, a polymeric aliphatic 5 diol, and optionally a chain extender.

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 comprising a polyoxazoline, and a polyurethane, the polyurethane comprising a backbone comprising the reaction product of a diisocyanate, a polymeric aliphatic 5 diol, and optionally a chain extender.

Disclosed herein are membranes, composition for forming membranes, methods for forming membranes, and sensors and other devices comprising membranes. The membrane comprises a polyurethane component, the polyurethane component comprising a blend of from 5 wt % to 95 wt %, based on the total weight of the polyurethane component, of an amphiphilic polyurethane, and from 5 wt % to 95 wt %, based on the total weight of the polyurethane component, of a hydrophobic polyurethane.

Disclosed is a 1D nanofibers quasi-aligned, grid structure cross-laminated, and pore distribution and size controlled 3D polymer nanofiber membrane, and manufacturing method thereof. A 3D polymer nanofiber membrane controlled in pore size and porosity is formed by employing an electrospinning pattern forming apparatus that includes double insulating blocks quasi-aligns nanofibers in a specific direction by transforming an electric field and includes a current collector rotatable in 90. Additionally, the 3D polymer nanofiber membrane may be used for air filters, separator, water filters, cell culture membranes, and so on by allowing various properties thereto through a functional surface coating.

Disclosed is a 1D nanofibers quasi-aligned, grid structure cross-laminated, and pore distribution and size controlled 3D polymer nanofiber membrane, and manufacturing method thereof. A 3D polymer nanofiber membrane controlled in pore size and porosity is formed by employing an electrospinning pattern forming apparatus that includes double insulating blocks quasi-aligns nanofibers in a specific direction by transforming an electric field and includes a current collector rotatable in 90. Additionally, the 3D polymer nanofiber membrane may be used for air filters, separator, water filters, cell culture membranes, and so on by allowing various properties thereto through a functional surface coating.

Provided herein are methods of making asymmetric membranes comprising a first layer and a second layer. The methods include preparing a polymeric solution comprising one or more polymers, casting the polymeric solution to form a polymeric film, contacting the polymeric film with a solvent comprising a crosslinker under conditions to form a first layer on the top of the film, wherein the first layer is dense and solvent resistant, and contacting the polymeric film having the dense, solvent-resistant first layer with a non-solvent solution under conditions that form a porous second layer on the bottom of the film.

Provided herein are methods of making asymmetric membranes comprising a first layer and a second layer. The methods include preparing a polymeric solution comprising one or more polymers, casting the polymeric solution to form a polymeric film, contacting the polymeric film with a solvent comprising a crosslinker under conditions to form a first layer on the top of the film, wherein the first layer is dense and solvent resistant, and contacting the polymeric film having the dense, solvent-resistant first layer with a non-solvent solution under conditions that form a porous second layer on the bottom of the film.