A provided stretched porous polytetrafluoroethylene membrane has a node-fibril structure including a plurality of nodes and a fibril connecting the plurality of nodes. A ratio of an average length of the plurality of nodes in a thickness direction of the stretched porous polytetrafluoroethylene membrane to a thickness of the stretched porous polytetrafluoroethylene membrane is 10% or more. The above stretched porous polytetrafluoroethylene membrane is less likely to suffer breakage. In the above stretched porous polytetrafluoroethylene membrane, assuming that there is a cuboid region having an upper surface and a lower surface respectively positioned at one membrane surface and the other membrane surface of the stretched porous polytetrafluoroethylene membrane, the number of the nodes included in the region may be 4 or less per micrometer thickness, the upper surface and the lower surface each having dimensions of 280 μm×280 μm.

Described herein are separation articles such as, for example, films, membranes and the like separating at least one component from a gaseous mixture comprising two or more components comprising difluoromethane (HFC-32, CH.sub.2F.sub.2) and pentafluoroethane (HFC-125, C.sub.2F.sub.5H). The disclosed articles include a “selective layer” that is selectively permeable for the desired component to be separated from the gas mixture. The selective layer is composed of an amorphous fluorinated copolymer. Optionally, the article may include other layers which serve various purposes such as, for example, a porous support layer, a “gutter layer,” which allows the permeate gas to pass from the selective layer to the porous layer with minimal flow impedance, and a protective layer, which protects the selective layer from fouling. Each component of the separation articles described herein and methods for making and using the same are provided below.

A polymer film has a loofah-like structure. It has a fibrous framework structure formed by three-dimensional interwoven and interconnected polymer fibers and a three-dimensional interconnected network pore structure distributed in the fibrous framework structure. The polymer is an organic polymer and the fibrous framework structure is integrally formed by the polymer. The film has a volume porosity of from 50% to 95%. The film is obtained by means of a combination method for atomization pretreatment and non-solvent phase separation. The film can be used in the fields of gas filtration, liquid filtration, oil-water separation, adsorption materials, catalysis, pharmaceutical sustained release materials, anti-adhesion coatings, oil delivery and oil spill interception.

A filtration membrane comprising cellulose fibres, the membrane having a pore size distribution such that the modal pore diameter is between 10 nm and 25 nm and/or wherein less than 5% of the pore volume comprises pores of greater than 40 nm and having a total porosity greater than 30%.

A microporous membrane has average membrane thickness of 15 μm or less, and relative impedance A after a heat compression treatment under a pressure of 4.0 MPa at 80° C. for 10 minutes of 140% or less, the relative impedance A being obtained by the equation below: Relative impedance A=(impedance measured at 80° C. after the heat compression treatment)/(impedance measured at room temperature prior to the heat compression treatment)×100.

The present disclosure provides an efficient and stable magnetic nanofiber membrane and a preparation method and use thereof, and belongs to the technical field of composites. The preparation method includes the following steps: dissolving polyacrylonitrile or polystyrene, nZVI particles, and n-octyltrimethylammonium bromide in N,N-dimethylformamide, and mixing uniformly to obtain a spinning solution; subjecting the spinning solution to electrospinning; and vacuum-drying a resulting fiber membrane to obtain the efficient and stable magnetic nanofiber membrane. In the present disclosure, the magnetic nanofiber membrane has a high specific surface area, a desirable porosity, an excellent mechanical strength, and satisfactory magnetic properties. The membrane effectively exerts a synergistic effect of the nZVI particles and an organic polymer material carrier, avoids easy oxidation of a catalyst surface and easy particle agglomeration, enhances a catalytic activity of the magnetic nanofiber membrane, and improves an efficiency in organic wastewater treatment.

The present disclosure provides a nanostructured cellulose membrane system with high porosity, and methods for making same. The cellulose membrane system includes carboxylate-functionalized cellulose nanofibers combined with a cellulose microfiber scaffold, which are attached by a crosslinking reaction between the nanofibers and/or between the nanofibers and the microfiber scaffold.

A porous polytetrafluoroethylene (PTFE) membrane of the present disclosure has a water vapor permeability, as measured according to Japanese Industrial Standard (JIS) L 1099 (method B-1), of 150000 g/(m.sup.2.Math.day) or more in a thickness direction of the membrane. The porous PTFE membrane of the present disclosure, when attached as a waterproof air-permeable membrane to a housing of an electrical component or electrical device, allows water vapor residing inside the housing to be quickly discharged out of the housing.

A porous polytetrafluoroethylene (PTFE) membrane of the present disclosure is a membrane having an average fibril length of 50 μm or more, having an average node length 5 or more times larger than the average fibril length, and having an average node area ratio of 5% or less. The porous PTFE membrane of the present disclosure, when attached as a waterproof air-permeable membrane to a housing of an electrical component or electrical device, allows water vapor residing inside the housing to be quickly discharged out of the housing.

In at least one embodiment, a separator is provided with a fibrous mat for retaining the active material on an electrode of a lead-acid battery. New or improved mats, separators, batteries, methods, and/or systems are also disclosed, shown, claimed, and/or provided. For example, in at least one possibly preferred embodiment, a composite separator is provided with a fibrous mat for retaining the active material on an electrode of a lead-acid battery. In at least one possibly particularly preferred embodiment, a PE membrane separator is provided with at least one fibrous mat for retaining the active material on an electrode of a lead-acid battery. In accordance with at least certain embodiments, aspects and/or objects, the present invention, application, or disclosure may provide solutions, new products, improved products, new methods, and/or improved methods, and/or may address issues, needs, and/or problems of PAM shedding, NAM shedding, electrode distortion, active material shedding, active material loss, and/or physical separation, electrode effectiveness, battery performance, battery life, and/or cycle life, and/or may provide new battery separators, new battery technology, and/or new battery methods and/or systems that address the challenges arising from current lead acid batteries or battery systems, especially new battery separators, new battery technology, and/or new battery methods and/or systems adapted to prevent or impede the shedding of active material from the electrodes, preferably or particularly in enhanced flooded lead acid batteries, PSoC batteries, ISS batteries, ESS batteries, and/or the like.