Disclosed is a hollow fiber membrane module including a case and a hollow fiber membrane built in the case, wherein the hollow fiber membrane contains a polysulfone-based polymer and a hydrophilic polymer, and satisfies the following (A) and (B), and an amount of an eluted substance contained in a liquid obtained by circulating ultrapure water heated at 37° C. through a passage of an inner surface side of the hollow fiber membrane for 4 hours at 200 mL/min is 1.0 mg/m.sup.2 or less: (A) an insoluble component accounts for less than 3% by mass of the total mass of the hollow fiber membrane when the hollow fiber membrane is dissolved in N,N-dimethylacetamide; and (B) a flexible layer exists on a surface of a functional layer in a wet state and the flexible layer has a thickness of 7 nm or more. The present invention provides a hollow fiber membrane module including a hollow fiber membrane containing a polysulfone-based polymer and a hydrophilic polymer built therein, which elutes little eluted substance and exhibits high biocompatibility, while change in performance due to crosslinking of the hydrophilic polymer is suppressed.

A composite membrane for selectively pervaporating a first liquid from a mixture comprising the first liquid and a second liquid. The composite membrane includes a porous substrate comprising opposite first and second major surfaces, and a plurality of pores. A PVP- or PVL-containing polymer is disposed in at least some of the pores so as to form a layer having a thickness within the porous substrate and/or disposed on top of the pores to form a layer.

A composite membrane for selectively pervaporating a first liquid from a mixture comprising the first liquid and a second liquid. The composite membrane includes a porous substrate comprising opposite first and second major surfaces, and a plurality of pores. A PVP- or PVL-containing polymer is disposed in at least some of the pores so as to form a layer having a thickness within the porous substrate and/or disposed on top of the pores to form a layer.

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.

A multi-layer membrane which has a mixed polyamide selective layer supported on a porous polysulfone layer. The mixed polyamide selective layer includes reacted units of a polyfunctional acyl halide (e.g. trimesoyl chloride) and a diamine mixture containing 4,7,10-trioxa-1,13-tridecanediamine and a cyclic diamine (e.g. piperazine). Methods of fabricating the multi-layer membrane via techniques such as phase inversion and interfacial polymerization are described. The inventive membrane is evaluated on its water flux and salt rejection (e.g. sulfate and chloride salts) capabilities. A water desalination system containing the multi-layer membrane(s) is also provided.

A porous membrane has a thickness of 150 m or greater. The pore diameters of a first surface are smaller than the pore diameters of a second surface. The average value of the pore diameters of the first surface is 60 nm or less, and the coefficient of variation of the pore diameters is 10% or greater and 50% or less.

A porous membrane has a thickness of 150 m or greater. The pore diameters of a first surface are smaller than the pore diameters of a second surface. The average value of the pore diameters of the first surface is 60 nm or less, and the coefficient of variation of the pore diameters is 10% or greater and 50% or less.

Disclosed is a statistical copolymer that includes both zwitterionic repeat units and hydrophobic repeat units, and a filtration membrane that contains a selective layer formed of the statistical copolymer. Also disclosed are methods of preparing the above-described filtration membrane.

Disclosed is a statistical copolymer that includes both zwitterionic repeat units and hydrophobic repeat units, and a filtration membrane that contains a selective layer formed of the statistical copolymer. Also disclosed are methods of preparing the above-described filtration membrane.

The present disclosure relates to improved semipermeable membranes based on acrylonitrile copolymers for use in dialyzers for the extracorporeal treatment of blood in conjunction with hemodialysis, hemofiltration or hemodiafiltration. The present disclosure further relates to methods of producing such membranes.