A method suppresses membrane thickness variation and air resistance variation after a compression at 60 C. or 80 C. Stretching is performed at least twice in at least different axial directions before the extraction of the solvent, and at the same time, at least one of (i) and (ii) is satisfied. (i) The step (c) is a first stretching step of stretching the sheet-shaped product at least once in a sheet transport direction (MD direction) and at least once in a sheet width direction (TD direction) individually, and the MD stretching magnification and the TD stretching magnification in the step (c) satisfy (TD stretching magnification MD stretching magnification2). (ii) The stretching temperature (T1) of a first axial stretching performed firstly in the step (c) and the maximal stretching temperature (T2) of a second stretching performed after the first axial stretching satisfy (T1T20).

The present disclosure is directed to ultrafiltration membranes based on bacterial nanocellulose and graphene oxide. In particular, the present disclosure is directed to the novel design and incorporation of membranes for realizing new, highly efficient, and environmentally-friendly anti-biofouling membranes for water purification.

Provided herein are methods for forming nanofibers. The current disclosure provides ceramic nanofibers, morphology-controlled ceramic-polymer hybrid nanofibers, morphology-controlled ceramic nanofibers, core-sheath nanofibers and hollow core nanofibers using ceramic precursor materials and polymer materials which are combined and undergo electrospinning. The current disclosure provides for methods of forming these nanofibers at low temperatures such as room temperature and in the presence of oxygen and moisture wherein the ceramic precursor cures to a ceramic material during the electrospinning process. Also disclosed are the nanofibers prepared by the disclosed methods.

A polymer comprising a sub-unit represented by Formula I:

##STR00001##

wherein:

L is independently selected from at least one arylene group, and a multi-ring moiety,

L is independently selected from L or is not present,

A and A are not present or are independently selected from an isatin moiety with the proviso that at least one of A and A is selected from an isatin moiety.

A microporous membrane has average membrane thickness of 15 m 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.

Fiber webs which are used in filter media are described herein. In some embodiments, the fiber webs include fibrillated fibers and optionally non-fibrillated fibers, amongst other optional components (e.g., binder resin). In some embodiments, the fiber webs include limited amounts of, or no, glass fiber. The respective characteristics and amounts of the fibrillated fibers are selected to impart desirable properties including mechanical properties and filtration properties (e.g., dust holding capacity and efficiency), amongst other benefits.

Cation exchange membranes and materials including silica-based ceramics, and associated methods, are provided. In some aspects, cation exchange membranes that include a silica-based ceramic that forms a coating on and/or within a porous support membrane are described. The cation exchange membranes and materials may have certain structural or chemical attributes (e.g., pore size/distribution, chemical functionalization) that, alone or in combination, can result in advantageous performance characteristics in any of a variety of applications for which selective transport of positively charged ions through membranes/materials is desired. In some embodiments, the silica-based ceramic contains relatively small pores (e.g., substantially spherical nanopores) that may contribute to some such advantageous properties. In some embodiments, the cation exchange membrane or material includes sulfonate and/or sulfonic acid groups covalently bound to the silica-based ceramic.

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.

A novel or improved base film for impregnation, impregnated base film, product incorporating the impregnated base film, and/or related methods as shown, claimed or described herein.

An object of the present invention is to provide a porous hollow-fiber membrane satisfying both high strength and high pure-water permeation performance and at the same time, having high bending resistance. The present invention relates to a porous hollow-fiber membrane including a fluororesin-based polymer, in which the porous hollow-fiber membrane has a columnar texture oriented in a longitudinal direction of the porous hollow-fiber membrane and when a photograph of a cross-section parallel to the longitudinal direction of the porous hollow-fiber membrane is binarized into a structure portion and a void portion, the following 1) and 2) are satisfied: 1) a proportion of an area of the void portion is from 20 to 50%, and 2) a value obtained by dividing a total of peripheral lengths of the void portions by a total of areas of the void portions is 2.0 ?m.sup.?1 or less.