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.

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 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.

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.

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.

A polyolefin multilayer microporous membrane is disclosed. The polyolefin multilayer microporous membrane has at least three layers, the membrane comprising a first microporous layer composed of a polyethylene resin containing an ultrahigh molecular weight polyethylene (surface layers) and a second microporous layer composed of a polyolefin rein containing a high-density polyethylene and polypropylene (intermediate layer), wherein (I) the pin puncture strength is at least 25 g/m, (II) the coefficient of static friction with respect to a metal foil is at least 0.40, and (III) the meltdown temperature is at least 180 C.

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.

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 retroviruses from liquid samples and a nanofiber containing liquid filtration medium that simultaneously exhibits high liquid permeability and high microorganism retention is disclosed. Retroviruses are removed from a liquid by passing the liquid through a porous nanofiber containing filtration medium having a retrovirus LRV greater than about 6, and the nanofiber(s) has a diameter from about 10 nm to about 100 nm. The filtration medium can be in the form of a fibrous electrospun polymeric nanofiber liquid filtration medium mat.

An embodiment of the invention provides a substrate for a liquid filter, the substrate including at least one A layer which is a microporous membrane-like layer containing a polyolefin, and at least one B layer which is a microporous membrane-like layer containing a polyolefin and a filler, the substrate having a bubble point of from 0.40 Mpa to 0.80 Mpa and a water permeation efficiency of from 1.0 mL/min.Math.cm.sup.2 to 4.0 mL/min.Math.cm.sup.2.