A catalytic composite is formed of a catalytic layered assembly including a porous catalytic fluoropolymer film and one or more felt batts connected with the porous catalytic fluoropolymer film. At least one felt batt is positioned adjacent the upstream side of the porous catalytic fluoropolymer film to form the catalytic composite. The fluoropolymer film is perforated to allow for enhanced airflow therethrough while retaining the capability of catalyzing the reduction or removal of chemical species in fluid flowing through the catalytic composite.

A hybrid type filtration structure for filtering liquid includes a first active layer, a porous supporting layer and a permeable layer. The first active layer has a first nano pore inner wall of which a function group included compound is combined with. The porous supporting layer has a plurality of pores and is disposed under the first active layer. The permeable layer is disposed under the porous supporting layer. The porous supporting layer includes a plurality of lipid bilayers having membrane protein inside of the pore, a molecule of water selectively passes through the membrane protein. The first nano pore passes through the first active layer vertically. The first nano pore and the pore are connected with each other through which liquid flows.

A polyolefin microporous membrane on which a porous layer has little fluctuations in thickness and a separator for batteries can adapt to the increase in capacity of a battery. A polyolefin microporous membrane having a range of fluctuation in a F25 value in the width direction of 1 MPa or less, a thickness of 3 m or more and less than 7 m and a width of 100 mm or more (wherein the term F25 value refers to a value produced by dividing the value of a load applied to a test specimen upon the stretching of the test specimen at a stretching ratio of 25% using a tension tester by the value of a cross-sectional area of the test specimen).

A polyolefin microporous membrane has excellent strength, permeability and heat resistance, which is obtained by using UHMwPE and employing a sequential stretching system, and a production method of the microporous membrane. In producing a microporous membrane by using a primary material A having a molecular weight (Mw) of less than 1.010.sup.6, a secondary material B having a molecular weight of 1.010.sup.6 or more, and a plasticizer, when the endothermic quantity of a mixture of the primary material and the plasticizer and the endothermic quantity of a mixture of the secondary material and the plasticizer are denoted as Q1 and Q2, respectively, respective resins are designed such that the ratio of endothermic quantity Q2 to endothermic quantity Q1 (endothermic quantity Q2/endothermic quantity Q1) becomes 1 or more over a temperature range of 110 to 118 C.

A method for forming porous fibers is provided. The fibers are formed from a thermoplastic composition containing a continuous phase, which includes a matrix polymer, and a nanoinclusion additive that is at least partially incompatible with the matrix polymer so that it becomes dispersed within the continuous phase as discrete nano-scale phase domains. The method includes traversing a bundle of the fibers through a multi-stage drawing system that includes at least a first fluidic drawing stage and a second fluidic drawing stage. The first drawing stage employs a first fluidic medium having a first temperature and the second drawing stage employs a second fluidic medium having a second temperature. The first and second temperatures are both lower than the melting temperature of the matrix polymer, and the first temperature is greater than the second temperature.

Asymmetric hollow fiber membranes, membrane contactors, and related production and use methods. The asymmetric hollow fiber membranes include a porous substrate having a multiplicity of pores, the porous substrate including at least a first semi-crystalline thermoplastic polyolefin copolymer derived by polymerizing at most 3 wt. % of linear or branched alpha olefin monomers with at least 97 wt. % of 4-methyl-1-pentene monomer. The asymmetric hollow fiber membranes also include a skin layer overlaying the porous substrate, the skin layer including a second semi-crystalline thermoplastic polyolefin copolymer derived by polymerizing at least 2 wt. % of linear or branched alpha olefin monomers with at most 98 wt. % of 4-methyl-1-pentene monomer. The skin layer is less porous than the porous substrate and forms an outer surface of the asymmetric hollow fiber membrane, while the porous substrate forms an inner surface of the hollow fiber membrane. The skin layer is preferably nonporous.

A polyolefin microporous membrane is disclosed. The membrane has a width of not less than 100 mm, and a variation range of an F25 value in a width direction is not greater than 1 MPa. The F25 value is a value obtained by dividing a load at 25% elongation of a sample of the laminated polyolefin microporous membrane as measured with a tensile testing machine by a cross-sectional area of the sample.

Methods are provided for producing a biaxially oriented nanoporous UHMWPE membrane. The method can include combining a petroleum jelly, an ultra-high-molecular-weight polyethylene (UHMWPE), and an antioxidant, forming a suspension, feeding the suspension into an extruder to produce a gel filament, pressing the gel filament to form a gel film, subjecting the gel film to an annealing temperature, and extracting the petroleum jelly from the gel film.

Hollow fiber membranes, membrane contactors, and related production and use methods. The membranes include a substrate having a multiplicity of pores and a skin layer overlaying the porous substrate. The porous substrate includes a first semi-crystalline thermoplastic polyolefin (co)polymer resin and a nucleating agent in an amount effective to achieve nucleation. The skin layer includes a second semi-crystalline thermoplastic polyolefin (co)polymer resin derived by polymerizing at most 98 wt. % of 4-methyl-1-pentene monomer with at least 2 wt. % of linear or branched alpha olefin monomers. Preferably, the first thermoplastic polyolefin (co)polymer is different from the second thermoplastic polyolefin (co)polymer. The skin layer is less porous than the porous substrate and forms an outer surface of the hollow fiber with the porous substrate forming an inner surface. The hollow fibers are formed by co-extruding the porous substrate resin and the skin layer resin through an annular die.

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).