In at least one embodiment, a microporous membrane having a moderate to high water vapor permeability and high liquid water penetration resistance is disclosed. The microporous membrane may be used in building applications, including as or as part of a building wrap, a rain screen, a roofing underlayment, a flashing, a sound proofing material, or an insulation material. The microporous membrane may include at least one thermoplastic polymer, at least one filler, and at least one processing oil. The microporous membrane may be flat or may have ribs. The microporous membrane may include at least one scrim component. A method for forming the microporous membrane is also disclosed.

The present invention provides a highly-permeable dense hollow fiber membrane (HFM) for blood oxygenation. A membrane material plays a key role in an oxygenator, which determines the oxygenation efficiency, service life and safety of the oxygenator. The HFM according to the present invention features high permeability. When blood rich in carbon dioxide flows through the oxygenator, the carbon dioxide and oxygen in the blood can be rapidly exchanged, so that the blood can be rapidly updated, and the size of the oxygenator and the blood perfusion volume can be reduced. In addition, the membrane surface of the present invention is hydrophobic and dense, and blood does not directly contact with gas or permeate into a gas pipeline, thus avoiding the problems of protein leakage, permeability reduction and the like. The oxygenator prepared by using the HFM of the present invention can be repeatedly used for a long time.

A crosslinked polyolefin separator and a method of making the same are disclosed herein. In some embodiments, a crosslinked polyolefin separator includes inorganic particles and a crosslinked polyolefin having Si—O—Si crosslinking bonds, wherein the inorganic particles are chemically bound to silicon (Si) atoms of the Si—O—Si crosslinking bonds by oxygen (O) atoms. The crosslinked polyolefin separator has low resistance, high air permeability and improved heat resistance.

Provided is a porous membrane having high filtration performance and little deterioration of water permeation performance due to membrane surface abrasion when used in a method of clarifying, by membrane filtration, turbid water that is natural water, domestic wastewater, or water resulting from treatment thereof. In the porous membrane, a ratio of internal porosity in a thickness up to 0.12% of membrane thickness from a topmost surface of a surface at a filtration feed side relative to surface porosity of the surface at the filtration feed side is 1.05 or more.

Disclosed herein is an improved membrane, separator and/or method for forming a multilayer microporous membrane for use in an improved battery separator, particularly a battery separator for a lithium ion secondary battery. Also disclosed herein is the multilayer microporous membrane formed by this method, which has properties that compete with or exceed those of wet process, coated or uncoated, membranes that are also useable in battery separators. Also disclosed are battery separators comprising the multilayer microporous membrane and batteries, vehicles, or devices comprising the separators. The method may comprise at least the following steps: (1) forming a stretched first non-porous precursor film that has pores due to the stretching of a first non-porous precursor film; (2) separately forming a second stretched non-porous precursor film that has pores due to the stretching of a second non-porous precursor film; and then (3) laminating the stretched first non-porous precursor and the stretched second non-porous precursor.

Described in the present application are methods of producing silane-crosslinked polymer membranes at moderate temperatures using acid catalysts that, in certain embodiments, result in membranes with unexpectedly high permeabilities and selectivities. In certain embodiments, grafting and crosslinking of the silanes occur by immersing a preformed membrane in a solution comprising a silane and an acid catalyst. Alternatively, in certain embodiments, grafting of silanes to a polymer occurs in the presence of acid catalyst in solution and subsequent casting and drying produces crosslinked membranes. In certain embodiments, an acid catalyst is a weak acid catalyst. Also described in the present application are asymmetric crosslinked polymer membranes with porous layers. In certain embodiments, crosslinked cellulose acetate membranes have permeability up to an order of magnitude greater than the permeability of unmodified cellulose acetate membranes. The membranes have porous layers with a high porosity due to their processing in moderate conditions.

The present disclosure provides a fluorine-based resin porous membrane exhibiting high mechanical strength and low heat shrinkage rate while having a fine pore size, and a method for preparing the same.

A membrane is a microporous sheet made of a blend of a first ultra high molecular weight polyolefin and a second ultra high molecular weight polyolefin. Each polyolefin has a molecular weight, both of those molecular weights are greater than 1 million, and one molecular weight is greater than the other. Additionally, the intrinsic viscosity (IV) of the membrane may be greater than or equal to 6.3.

A novel fibrous membrane comprises at least one substrate layer comprising at least 80% by weight of microfibers that carry positively charged and/or negatively charged functional groups, and at least one layer of filtration material attached to the substrate layer, wherein the layer of filtration material comprises at least 80% by weight of nanofibers that carry negatively charged and/or positively charged functional groups. The fibrous membrane is able to remove or reduce the concentration of bacteria, viruses and heavy metals while maintaining relatively high water flow. A filter comprising the fibrous membrane and a method for manufacturing the fibrous membrane are also provided.

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.