A method for removing microorganisms from liquid samples and a nanofiber containing liquid filtration medium that simultaneously exhibits high liquid permeability and high microorganism retention. Microorganisms such as bacteria, particularly B. Diminuta, are removed from a liquid by passing the liquid through a porous nanofiber containing filtration medium having a B. Diminuta LRV greater than about 9, and the nanofiber(s) has a diameter from about 10 nm to about 1,000 nm. Another method for removing microorganisms such as bacteria and Mycloplasma, includes passing the liquid through a porous nanofiber containing filtration medium having a microorganism LRV greater than about 8, and the nanofiber(s) has a diameter from about 10 nm to about 1,000 nm. The filtration medium can be in the form of a fibrous electro spun polymeric nanofiber liquid filtration medium mat.

The present invention is directed to a process for the preparation of a tube with an outer diameter in the range of from 10 m to 250 m consisting of a composition comprising a thermoplastic polyurethane as well as to a tube with an outer diameter in the range of from 10 m to 250 m consisting of a composition comprising a thermoplastic polyurethane obtained or obtainable by the process according to the invention. The invention is further directed to the use of a tube according to the invention as a tube for the transportation of a fluid or as gas membrane tube or as an elastic fiber.

Compositions of and methods for separating components of a natural gas stream are disclosed. In one embodiment, the method includes receiving an inlet stream comprising natural gas, the inlet stream having an inlet pressure, and the inlet stream further comprising methane, helium, and an impurity. The method includes allowing the inlet stream to contact a block co-polyimide membrane, the block co-polyimide membrane exhibiting both higher permeability for and higher selectivity for the helium and the impurity than for the methane at the inlet pressure of the inlet stream and separating the methane from the helium and the impurity to create a retentate stream, the retentate stream comprising an increased concentration of methane relative to the inlet stream. The method also includes creating a permeate stream comprising the helium and the impurity at an increased concentration of helium and impurity relative to a concentration of helium and impurity in the inlet stream.

A method for removing microorganisms from liquid samples and a nanofiber containing liquid filtration medium that simultaneously exhibits high liquid permeability and high microorganism retention. Microorganisms such as bacteria, particularly B. Diminuta, are removed from a liquid by passing the liquid through a porous nanofiber containing filtration medium having a B. Diminuta LRV greater than about 9, and the nanofiber(s) has a diameter from about 10 nm to about 1,000 nm. Another method for removing microorganisms such as bacteria and Mycloplasma, includes passing the liquid through a porous nanofiber containing filtration medium having a microorganism LRV greater than about 8, and the nanofiber(s) has a diameter from about 10 nm to about 1,000 nm. The filtration medium can be in the form of a fibrous electro spun polymeric nanofiber liquid filtration medium mat.

Provided are a polyethylene microporous membrane, a method for manufacturing the same, and a separator including the microporous membrane. According to an embodiment, a polyethylene microporous membrane which has a thickness of 3 ?m to 30 ?m, a puncture strength of 0.15 N/?m or more, a shrinkage rate in the transverse direction of 5% or less as measured after being allowed to stand at 121? C. for 1 hour, and a PS index represented by the following Equation 1 of 110 or more is provided:

PS index=[gas permeability (?10.sup.31 5 Darcy)?porosity (%)]+[shrinkage rate (%) in the transverse direction at 121? C.]. [Equation 1]

The problem of the present invention is to provide a novel polytetrafluoroethylene porous film having a small pore diameter, small film thickness, high porosity, and high strength, and a production method thereof. The present invention provides a polytetrafluoroethylene porous film, wherein a bubble point in isopropyl alcohol (IPA) according to JIS K3832 is not less than 400 kPa, and a tensile strength based on JIS K6251 is not less than 50 MPa.

A problem to be solved by the present invention is to provide a separation membrane having excellent separation performance, having high membrane strength and high permeation performance, and mainly including a cellulose-based resin. The present invention is concerned with a separation membrane including a cellulose ester, having, in the interior thereof, voids each having a specified structure, and having a tensile elasticity of 1,000 to 6,500 MPa.

Provided is a novel continuous single-step method of manufacturing a multilayer sorbent polymeric membrane having superior productivity, properties and performance. At least one layer of the polymeric membrane comprises sorbent materials and a plurality of interconnecting pores. The method includes: (a) coextruding layer-forming compositions to form a multilayer coextrudate; (b) casting the coextrudate into a film; (c) extracting the film with an extractant; and (d) removing the extractant from the extracted film to form the multilayer sorbent polymeric membrane. The sorbent membrane of this disclosure can find a wide range of applications for use in filtration, separation and purification of gases and fluids, CO.sub.2 and volatile capture, structural support, vehicle emission control, energy harvesting and storage, electrolyte batteries. device, protection, permeation, packaging, printing, and etc.

There is provided a method for preparing microporous hollow fiber membranes comprising melt-extruding a polymer-salt blend followed by salt leaching. Microporous hollow fiber membranes are also disclosed.

The present invention is directed to methods of treating a hydrocarbon-containing waste stream to form a hydrocarbon-containing retentate and an aqueous permeate which is substantially free of hydrocarbon. The method includes passing the hydrocarbon-containing waste stream through a microporous membrane to yield the hydrocarbon-containing retentate and the aqueous permeate. The membrane comprises a substantially hydrophobic, polymeric matrix and substantially hydrophilic, finely divided, particulate filler distributed throughout the matrix. The polymeric matrix has pores with a volume average diameter less than 1.0 micron, and at least 50 percent of the pores have a mean diameter of less than 0.35 micron.