The present invention addresses the problem of providing: a method for purifying a liquid using a porous polyimide and/or polyamideimide membrane having excellent impurities (e.g., metals) removal performance which is preferably compatible with a flow rate, and also having an excellent stress, an excellent breaking elongation and the like; a method for producing a chemical solution or a cleaning solution employing the purification method; a filter medium comprising the porous membrane; and a filter device equipped with the porous membrane. A method for purifying a liquid, comprising causing a portion or the whole of the liquid to pass through a porous polyimide and/or polyamideimide membrane having communicated pores from one side of the membrane to the other side of the membrane by the action of a differential pressure between the two sides.

Micro- or nano-pores are produced in a membrane for various applications including filtration and sorting functions. Pores with at least one cross-sectional dimension in or near the nano-scale are provided. Device designs and processing allow for the use of thin film disposition and nano-imprinting or nano-molding to produce arrays of nano-pores in membrane materials function ing in applications such as filtration membranes, drug application/control structures, body fluid sampling structures, and sorting membranes. The nano-imprinting or nano-molding approach is utilized to create nano-elements in an organic or inorganic mold material with at least one nano-element cross-sectional dimension in or close to the nano-scale. These nano-elements can be in various shapes including slits, cones, columns, domes, and hemispheres.

A hybrid porous structured material may include a matrix including a plurality of first pores interconnected in three dimensions, and a porous material including second pores and filling wholly or partially each of the plurality of the first pores.

The present invention relates to the use of a porous polymer etched ion-track membrane as separator for batteries comprising a positive electrode, a negative electrode and a liquid electrolyte comprising at least one salt of a cationic ion in solution in a solvent, and to batteries comprising such a membrane as porous separator.

Porous liquid-filtering membranes having a repeatable distribution of pores of a small dimension are provided, as well as pillar templates that are used to produce such liquid filtering membranes. Also disclosed are methods of making and using the pillar templates to make porous liquid filtering membranes.

A microporous membrane is made by a dry-stretch process and has substantially round shaped pores and a ratio of machine direction tensile strength to transverse direction tensile strength in the range of 0.5 to 5.0. The method of making the foregoing microporous membrane includes the steps of: extruding a polymer into a nonporous precursor, and biaxially stretching the nonporous precursor, the biaxial stretching including a machine direction stretching and a transverse direction stretching, the transverse direction stretching including a simultaneous controlled machine direction relax.

There is provided a production method for a resist composition purified product, which includes a step (i) of filtering a resist composition with a filter having a porous structure in which adjacent spherical cells are connected to each other. The filter includes a porous membrane containing at least one resin selected from the group consisting of polyimide and polyamide imide. The resist composition contains a base material component (A) that exhibits changed solubility in a developing solution under action of acid, an onium salt, and an organic solvent component (S), where the content of the organic solvent component (S) is 97% by mass or more.

The present disclosure provides a high-efficiency degassing polyolefin hollow fiber membrane and a preparation therefor and use thereof. The membrane comprises a main body, wherein one side of the main body is an inner surface facing an inner cavity, the other side of the main body is an outer surface, a non-directional tortuous pathway is formed in the main body, the outer surface is a dense surface, and the area ratio of air pores in the inner surface is 10%-30%; the average thickness of the hollow fiber membrane is 45-65 m and the ratio of the average outer diameter to the average inner diameter of the hollow fiber membrane is 1.45-1.55; the TOC dissolving-out amount of the hollow fiber membrane itself is less than or equal to 0.5 g/L; and the deoxidation efficiency of the hollow fiber membrane is greater than 80%.

Methods and apparatus for forming apertures in a solid state membrane using dielectric breakdown are provided. In one disclosed arrangement a plurality of apertures are formed. The membrane comprises a first surface area portion on one side of the membrane and a second surface area portion on the other side of the membrane. Each of a plurality of target regions comprises a recess or a fluidic passage opening out into the first or second surface area portion. The method comprises contacting all of the first surface area portion of the membrane with a first bath comprising ionic solution and all of the second surface area portion with a second bath comprising ionic solution. A voltage is applied across the membrane via first and second electrodes in respective contact with the first and second baths comprising ionic solutions to form an aperture at each of a plurality of the target regions in the membrane.

The present invention relates to a method for producing a porous membrane, the method being characterized in that a solvent system comprising 2-pyrrolidone and N-alkyl-2-pyrrolidone is used, wherein the content ratio of 2-pyrrolidone to N-alkyl-2-pyrrolidone in the solvent system is from 90%:10% to 10%:90%, based on mass %, and wherein N-alkyl-2-pyrrolidone is N-propyl-2-pyrrolidone and/or N-butyl-2-pyrrolidone. Furthermore, the present invention relates to a porous membrane obtainable by said method. Moreover, the present invention relates to the use of a specific solvent system for the production of a porous membrane.