A mesoporous isoporous asymmetric material includes at least one diblock or multiblock copolymer, wherein the material has a transition layer having a thickness of at least 300 nm and a low macrovoid density, and the material has a sub-structure adjacent to said transition layer and said sub-structure comprises a high macrovoid density. A method for producing mesoporous isoporous asymmetric materials having macrovoids can include: dissolving at least one diblock or multiblock copolymer in a solution, the solution having one or more solvents and one or more nonsolvents, to form a polymer solution; dispensing the polymer solution onto a substrate or mold, or through a die or template; removing at least a portion of solvent and/or nonsolvent from the polymer solution to form a concentrated polymer solution; and exposing the concentrated polymer solution to a nonsolvent causing precipitation of at (least a portion of the polymer from the concentrated polymer solution.

A filter for filtering nucleated cells that includes a body containing at least either a metal or a metal oxide as its main component; and plural through holes, each of which have a shape other than a square shape, formed therein. A longitudinal diameter of an inscribed ellipse within each of the through holes is smaller than a size of a nucleus of each of the nucleated cells to be filtered. The inscribed ellipse of the through hole is an ellipse that abuts all sides that define an opening of the through hole.

The present technology provides micro fabricated filtration devices, methods of making such devices, and uses for microfabricated filtration devices. The devices may allow diffusion to occur between two fluids with improved transport resistance characteristics as compared to conventional filtration devices. The devices may include a compound structure that includes a porous membrane overlying a support structure. The support structure may define a cavity and a plurality of recesses formed in a way that can allow modified convective flow of a first fluid to provide improved diffusive transport between the first fluid and a second fluid through the membrane.

A composite porous membrane contains at least one porous base layer and at least one uniaxially stretched coating layer located on at least one side surface of the porous base layer. For example, the composite porous membrane comprises at least one porous base layer and at least one nanofiber-like non-polyolefin polymer porous layer oriented along the transverse stretching direction of the composite porous membrane and located on one or two side surfaces of the porous base layer, or the composite porous membrane comprises a biaxially stretched polypropylene porous base layer and a uniaxially stretched coating layer located on at least one side surface of the porous base layer. The composite porous membrane is coated with a coating solution prior to transversely stretching. The nanofiber-like non-polyolefin polymer porous layer may reduce cracking of the composite porous membrane in the machine direction.

The present invention is directed towards a method for the preparation of macroporous or mesoporous polymer films in hollow fiber geometry. The method according to the present invention reliably produces macroporous or mesoporous homopolymer or copolymer films in hollow fiber geometry having an ordered porous structure. Preferably, the pores are isoporous. The method involves the purging or casting a polyol adjacent to a film forming polymer solution of at least one homopolymer or at least one copolymer in a suitable solvent while polyol diffuses in and then condenses out of the film forming solution before the solution is immersed into a coagulation bath. The methods also require the presence of a carrier solution or carrier substrate during spinning or casting. The method makes macroporous or mesoporous film formation possible with a single step processing method.

Provided are a porous film having excellent surface smoothness and a method for producing the same. The surface roughness of a porous film of polyvinylidene fluoride, polyethersulfone, polyimide and/or polyamide-imide is Ra 30,000 or less. The opening diameter of the porous film is preferably from 100 nm to 5000 nm. The method for producing a porous film preferably includes a step for kneading a varnish containing fine particles and at least one resin selected from the group consisting of polyvinylidene fluoride, polyether sulfone, polyamic acid, polyimide, polyamide-imide precursor, and polyamide-imide. The varnish preferably has a viscosity at 25 C. of 0.1-3 Pa.Math.s, a solids fraction concentration of 10-50 mass %, and a fine particle average particle size of 10-5000 nm.

A method for forming an isoporous graded film comprising multiblock copolymers and isoporous graded films. The films have a surface layer and a bulk layer. The surface layer can have at least 110.sup.14 pores/m.sup.2 and a pore size distribution (d.sub.max/d.sub.min)) of less than 3. The bulk layer has an asymmetric structure. The films can be used in filtration applications.

Provided is a water-treatment filter module, an apparatus and a method for manufacturing a helical strand for a water-treatment filter module, and a method for manufacturing a spacer. Also provided is a water-treatment filter module comprising a membrane for filtering raw water, and a spacer laminated to the membrane and providing a plurality of passages for passing the raw water through to the membrane, wherein the spacer includes a first member extending in a first direction and a second member extending in a second direction that is different from the first direction and disposed so as to form spacer cells by intersecting with the first member, and at least one of the first member and the second member is wound in a spiral shape having a predetermined pitch of a predetermined radius around a central axis.

Provided is a porous membrane which has a high water permeability performance, a high blocking performance, and a durability performance against loads of long-term and high operation pressures, which are suitable for filtering applications. The porous membrane includes one surface to be on a side of a filtrate; and the other surface to be on a side of a liquid to be filtered, wherein a surface pore diameter index of the one surface is 2.5 or more, the surface pore diameter index being determined by dividing a pore diameter in a top surface by a pore diameter in a second top surface.

A separation recovery system for separating and recovering an object to be separated includes a metal porous membrane which has a first principal surface and a second principal surface facing the first principal surface and has a plurality of through-holes extending between the first principal surface and the second principal surface, a supply device which supplies a first fluid containing the object to be separated from the first principal surface of the metal porous membrane toward the second principal surface, and a backwash device which supplies a second fluid containing a plurality of particles larger than a size of the plurality of through-holes of the metal porous membrane in a direction from the second principal surface of the metal porous membrane toward the first principal surface.