A separation membrane has high strength and low leakage property while maintaining high gas permeability using poly(4-methyl-1-pentene) excellent in chemical resistance and gas permeability. The separation membrane contains poly(4-methyl-1-pentene) as a main component, in which a ratio RA of a rigid amorphous of poly(4-methyl-1-pentene) in the separation membrane is 43% or more and 60% or less, a porosity is 30% or more and 70% or less, and a dense layer is provided on at least one surface.

An improved strength microporous membrane is described herein. The microporous membrane may be useful as a battery separator, separator membrane, base film, or membrane with a variety of uses thereof. The improved microporous membranes described herein may be dry process polyolefin membranes and may be used as battery separators or as a component of a composite or battery separator. The battery separators or composites may be used in energy storage devices including primary batteries, secondary batteries, fuel cells, capacitors, or super capacitors.

A nonwoven web obtained by electrospinning, suitable for the filtration of nano- and/or submicron aerosols, including a multiplicity of fibers of composition C1, the composition C1 including at least 50% by weight of at least one polymer P1 based on the repeat unit resulting from vinylidene fluoride (VDF), the fibers of composition C1 having a degree of crystallinity in polar phase(s), preferentially in solely beta phase, of at least 65% by weight, with respect to their total weight. Also, a process for the manufacture of the web, to a membrane including the web and also to a process for the washing/sterilization of the web or of the membrane.

The present invention relates to a method for preparing a supported MOF membrane induced by a low-crystal aggregation structure, as well as the MOF membrane and applications thereof. The preparation method includes the following steps: 1) depositing Al-MOF seeds on the surface of a porous support to obtain an Al-MOF seed layer; 2) placing the porous support with the deposited Al-MOF seed layer on its surface in a supersaturated solution for reaction, so as to grow a continuous low-crystal Al-MOF aggregate layer on the surface of the porous support; 3) performing a crystallization reaction on the porous support with the continuous low-crystal Al-MOF aggregate layer grown on its surface to obtain the Al-MOF membrane material; the supersaturated solution includes aluminum salt, ligand and coordination regulator. This method can prepare dense high-valence metal MOF crystal membrane materials, which can be used for efficient separation in various molecular-scale separation systems.