The present invention provides a separation membrane that is usable at a high temperature and a high pressure. The solvent-resistant separation membrane of the present invention has an average pore diameter of the separation membrane surface of 0.005 to 1 μm and includes a portion where a degree of cyclization (I.sub.1600/I.sub.2240) as measured by the total reflection infrared absorption spectroscopy is 0.5 to 50.

A method for preparing a nanoporous membrane includes alternatively repeating, on the surface of a porous substrate, the laminating of a hydrophilic homopolymer and the laminating of an amphiphilic block or graft copolymer to provide a polymer multilayer film in which the alternative laminate of the hydrophilic homopolymer and the amphiphilic block or graft copolymer is formed. The polymer multilayer film is annealed to form a microphase separated polymeric membrane. The laminating of a hydrophilic homopolymer and the laminating of a supramolecular structure compound are alternatively repeated, on the surface of the polymeric membrane, to form the alternative laminate of the hydrophilic homopolymer and the supramolecular structure compound.

A method for preparing a nanoporous membrane includes alternatively repeating, on the surface of a porous substrate, the laminating of a hydrophilic homopolymer and the laminating of an amphiphilic block or graft copolymer to provide a polymer multilayer film in which the alternative laminate of the hydrophilic homopolymer and the amphiphilic block or graft copolymer is formed. The polymer multilayer film is annealed to form a microphase separated polymeric membrane. The laminating of a hydrophilic homopolymer and the laminating of a supramolecular structure compound are alternatively repeated, on the surface of the polymeric membrane, to form the alternative laminate of the hydrophilic homopolymer and the supramolecular structure compound.

Methods of making blended, isoporous, asymmetric (graded) films (e.g. ultrafiltration membranes) comprising two or more chemically distinct block copolymers and blended, isoporous, asymmetric (graded) films (e.g. ultrafiltration membranes) comprising two or more chemically distinct block copolymers. The generation of blended membranes by mixing two chemically distinct block copolymers in the casting solution demonstrates a pathway to advanced asymmetric block copolymer derived films, which can be used as ultrafiltration membranes, in which different pore surface chemistries and associated functionalities can be integrated into a single membrane via standard membrane fabrication, i.e. without requiring laborious post-fabrication modification steps. The block copolymers may be diblock, triblock and/or multiblock mixes and some block copolymers in the mix may be functionally modified. Triblock copolymers comprising a reactive group (e.g., sulfhydryl group) terminated block and films comprising the triblock copolymers.

Disclosed are methods for preparing a thin film composite membrane by subjecting a solution comprising one or more zwitterionic copolymers to an electrospraying process, thereby preparing the thin film composite membrane.

Provided are certain membranes useful in the filtration of liquids and removal of various contaminants therein. In certain aspects the membranes have as one component a polyamide such as Nylon 11 and/or Nylon 12. Also provided is methodology for manufacturing such membranes and their use in filtration and purification of liquids. Membranes of the disclosure thus prepared exhibit superior acid stability when compared to polyamide membranes prepared from Nylon 6 or Nylon 6,6.

A two-layer membrane including a polymer layer and a support layer, the polymer layer being disposed on a surface of the support layer. The polymer layer, having a pore size of at most 50 nm and a thickness of 5 nm to 10 μm, is formed of an amphiphilic copolymer that contains both charged groups and hydrophobic groups. The support layer has a pore size of 3 nm to 10 μm, which is larger than the pore size of the polymer layer. Also disclosed is a process of filtering a liquid using the two-layer membrane described above.

The present invention relates to a composite semipermeable membrane including: a supporting membrane including a substrate and a porous supporting layer; and a separation functional layer disposed on the porous supporting layer, in which the separation functional layer includes: a crosslinked polyamide; and a hydrophilic polymer which is a polymer of a monomer having an ethylenically unsaturated group, and a surface of the separation functional layer has a ratio of the number of oxygen atoms to the number of nitrogen atoms (O/N ratio), both determined by X-ray photoelectron spectrometry, of 1.5-10, and a standard deviation of the O/N ratio of 0.15 or larger.

There are provide a cell separation filter with which cells can be separated without damage and can suppress adsorption, a filtering device, and a manufacturing method for a cell separation filter. The cell separation filter is composed of a nonwoven fabric that is formed of fibers containing a water-insoluble polymer and a hydrophilizing agent and has a fiber density difference in the film thickness direction. The nonwoven fabric has an average through-hole diameter of 2.0 μm or more and less than 10.0 μm, a void ratio of 75% or more and 98% or less, a film thickness of 100 μm or more, and a critical wet surface tension of 72 mN/m or more.

A bilayer electrospun membranes for treating hydraulic fracking wastewater via membrane distillation, and more particularly to bilayer electrospun membranes having an omniphobic layer to prevent low-surface tension solution wicking and an oleophobic antifouling surface to prevent foulant depositing on the membrane. Nanoparticles are decorated on the omniphobic surface through electrochemical interaction, which is coated with a fluorine monomer on the nanoparticles. A zwitterionic co-polymer is grafted using self-assembly between hydroxy groups on the antifouling surface generated by alkaline treatment and anchor segment epoxy groups on zwitterionic co-polymer.