A sheet filter membrane is arranged on a surface of a filter plate of a thermoplastic resin, and a plurality of projections provided in a hot plate is pressed against the filter plate above a periphery of the filter membrane with different timing for each of the projections to abut on the filter membrane. A plurality of recessed bonding portions with different depths are thus formed in the filter plate, and the filter membrane is bonded to the filter plate by heat welding in each of the recessed bonding portions. Sealing is therefore provided between the filter membrane and the filter plate along the periphery of the filter membrane.

Provided are an inexpensive, high-quality, permeation-side flow path material that is suitable for use in spiral membrane elements and enables the improvement of productivity, a method for producing such a permeation-side flow path material, and a membrane element having such a permeation-side flow path material. Provided are (a) a permeation-side flow path material for use in a spiral membrane element, the permeation-side flow path material comprising a resin sheet comprising a plurality of ridge portions 31 formed parallel to one another; and a plurality of openings 32 formed between each pair of the ridge portions 31, (b) a method for producing such a permeation-side flow path material, and (c) a membrane element having such a permeation-side flow path material.

A filtration module according to an embodiment of the present invention includes a plurality of hollow fiber membranes held while being aligned in one direction and a pair of holding members that fix both ends of the hollow fiber membranes. In the holding members, an existence region where the hollow fiber membranes exist has a rectangular shape in a direction perpendicular to the direction in which the hollow fiber membranes are aligned; a ratio of an average length of the existence region in a long side direction to an average length of the existence region in a short side direction is 10 or more and 50 or less; an average outer diameter of the hollow fiber membranes is 1 mm or more and 6 mm or less; and a ratio of an average effective length of the hollow fiber membranes between the holding members to the average length of the existence region in the short side direction is 40 or more and 200 or less.

A thin micro-porous membrane sheet and filtering device using it is presented. The membrane sheet includes a thin porous metal sheet of thickness between 20 and 200 μm with a porous ceramic coating of thickness less than 25 μm on at least one of its surfaces. The porous metal sheet has mean pore sizes at micro and sub-micrometer level and has a surface substantially free of pores greater than 10 micrometers. The ceramic coating layer may be made of particles with a mean particle size in a range of 10 to 300 nm and contains certain sintering promoters. The ceramic coating is sintered with the metal sheet in non-oxidizing environment at lower temperatures than typical ceramic membranes. The thin membrane sheet is used to filter fine particulates from micrometers to nanometers from a liquid or gas stream. The thin membrane sheet may be assembled into a filter device having high surface area packing density and straight mini-flow channels.

A semipermeable ultrathin polymer membrane is a microfluidic device that comprises a substantially optically transparent polymer film having a surface area to thickness ratio of at least 1,000,000:1, and an array of precisely spatially ordered pores of a user-selected diameter defined therethrough. Such membranes can be fabricated by providing a mold having a patterned array of nanoholes femtosecond laser ablated in a surface thereof; applying a first polymer solution onto the mold surface so that the first polymer solution infiltrates the nanoholes; allowing the first polymer solution to dry and form a replica of the mold having a plurality of freestanding nanoneedles extending from a surface of the replica; removing the replica from the mold; coating the replica surface with a second polymer solution; drying the second polymer solution to form a porous polymer film; and dissolving the replica in a solvent to release the film from the replica as a semipermeable ultrathin polymer membrane. Also disclosed are multi-chambered microfluidic devices for studying cell biology in vitro that incorporate one or more such semipermeable ultrathin polymer membranes.

Provided is a post-formation process for preparation of a highly permeable thin film composite membranes for reverse osmosis, particularly for use with brackish water at low energy conditions. The process includes contacting a polyamide discrimination layer of a TFC membrane with a solution containing an oxidizing agent to form a treated membrane, followed by contacting the treated membrane with a solution containing a reducing agent. The resulting membrane exhibits enhanced water flux while maintaining salt rejection. Also provided are reverse osmosis membranes prepared in accord with the method, and modules containing the highly permeable thin film composite membranes, and methods of purifying water using the membranes or modules.

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.

The present invention relates to a method of manufacturing a high-performance thin film composite (TFC) membrane through a solvent activation process. In the present invention, by using a mixed solvent of a good solvent and a poor solvent as an activating solvent, a conventional polysulfone-based support-based TFC membrane having high water permeance as well as excellent salt rejection may be manufactured.

A composite material contains a nonwoven layer (i) which contains fibers formed from a first thermoplastic elastomer having meshes with a mesh size in the range from 10 to 100 μm, and a membrane layer (ii) which contains a second thermoplastic elastomer and having a layer thickness of less than 30 μm. The membrane is either pore-free (ii.1) or is porous and has pores with an average pore diameter of less than 2000 nm (ii.2). The membrane (ii) is at least partially in direct contact with the fibers of the nonwoven layer (i) and covers the mesh openings in the nonwoven layer (i) at least partially. The fibers of the first nonwoven layer (i) and the membrane (ii) in the contact area are at least partly joined to one another in an interlocking manner.

Composite membrane tubing includes a porous scaffold support combined with polyether block amide copolymer. The composite membrane tubing has overlapping “fusion areas” that are an artifact of the manufacturing process. The methods of manufacturing above-mentioned composite membrane tubing have also been addressed. The composite membrane tubing can be reinforced with a structural mesh to further provide rigidity and strength. Composite membrane tubing or generally extruded tubing can be integrated into a multi-tube module for various applications.