Provided are a polyethylene microporous membrane, a method for manufacturing the same, and a separator including the microporous membrane. According to an embodiment of the present disclosure, a microporous membrane is provided which includes a polyethylene having a weight average molecular weight of 1?10.sup.5 g/mol to 10?10.sup.5 g/mol, and has a thickness of 3 ?m to 20 ?m, a puncture strength of 0.25 N/?m or more, a gas permeability of 1.5?10.sup.?5 Darcy or more, a shrinkage rate in the transverse direction of 10% or less as measured after being allowed to stand at 131? C. for 1 hour, a tensile strength in the machine direction of 1500 kg/cm.sup.2 or more, a tensile strength in the transverse direction of 2000 kg/cm.sup.2 or more, and a ratio between the tensile strength in the machine direction and the tensile strength in the transverse direction of 0.5 to 0.7.

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]

Provided are a polypropylene microporous membrane, a method for manufacturing the same, and a separator including the microporous membrane. According to an embodiment, a polypropylene microporous membrane including a polypropylene having a viscosity average molecular weight of 1?10.sup.6 g/mol to 3?10.sup.6 g/mol, a thickness of 3 ?m to 30 ?m, and exhibits a puncture strength of 0.20 N/?m or more, a gas permeability of 1.0?10.sup.?5 Darcy or more, and a shrinkage rate in the transverse direction of 20% or less as measured after being allowed to stand at 150? C. for 1 hour, is provided.

A hollow fiber membrane and a method of preparing the same. The hollow fiber membrane has an inner surface and an outer surface, wherein the inner surface has a zebra-stripe pattern in which a dense portion and a porous portion are alternately formed in a longitudinal direction of the hollow fiber membrane.

A desalination apparatus and a method of desalinating thereof, wherein the desalination apparatus comprises a perforated vessel and at least one engineered semi-permeable membrane that covers perforations on the perforated vessel, wherein the desalination apparatus forms a purified water from saline water when submerged in the saline water to a depth of 50-250 m to create sufficient pressure differential on both sides of the engineered semi-permeable membrane, wherein low-saline water flows through the engineered semi-permeable membrane and collected within an internal cavity of the desalination apparatus. Various embodiments of the desalination apparatus and the method of desalinating are also provided.

An object of the present invention is to provide a porous hollow-fiber membrane having high strength while maintaining high pure-water permeation performance. A porous hollow-fiber membrane of the present invention is a porous hollow-fiber membrane including a fluororesin-based polymer, in which the porous hollow-fiber membrane has a columnar texture oriented in a longitudinal direction of the porous hollow-fiber membrane, and a molecular chain of the fluororesin-based polymer is oriented in the longitudinal direction of the porous hollow-fiber membrane.

A two-layer membrane including a polymer layer and a support layer, the polymer layer being disposed on a surface of the support layer. The polymer layer, having a pore size of at most 50 nm and a thickness of 5 nm to 10 m, is formed of an amphiphilic copolymer that contains both charged groups and hydrophobic groups. The support layer has a pore size of 3 nm to 10 m, which is larger than the pore size of the polymer layer. Also disclosed is a process of filtering a liquid using the two-layer membrane described above.

A hydrogen peroxide production method, system, and apparatus is provided for producing large volumes of hydrogen peroxide having concentrations up to and excess of 80% in one continuous cycle. In one aspect, the method can include mixing NQO1 enzyme, an NQO1 activated compound or molecule, and an NADH or NADPH cofactor with an aqueous solution, dispensing the aqueous solution within or onto a semi-permeable membrane, wherein the semi-permeable membrane further includes a pre-defined molecular weight barrier. In addition, an oxidation-reduction reaction of the NQO1 enzyme, the NQO1 activated compound or molecule, and the NADH or NADPH cofactor within the aqueous solution produce hydrogen peroxide at a concentration level. Here, the produced hydrogen peroxide is above the pre-defined molecular weight barrier of the semi-permeable membrane and diffuses through the semi-permeable membrane to be extracted for use.

A method for creating a seawater desalination reverse osmosis membrane that excels in both water flux and boron removal. The method utilizes the abundant and reactive amino groups of carbon nitride in an interfacial polymerization reaction to enhance the membrane's structure. The unique pore and interlayer structure of carbon nitride is employed to modify the membrane's hydrophilicity, roughness, and interlayer structure, thereby boosting its water flux and boron removal capabilities. Additionally, the carbon nitride solution demonstrates exceptional dispersion properties. Its hydrophilic amino groups react with the organic phase monomer trimesoyl chloride during polymerization, ensuring an even distribution in the polyamide layer without any agglomeration. The evenly dispersed m-phenylenediamine and carbon nitride solution, along with sodium hydroxide in the aqueous phase, quicken the acylation reaction rate. This not only ensures more uniform participation of carbon nitride in the reaction but also further enhances the membrane's water flux and boron removal efficiency.

A method for producing a microporous material comprising the steps of: providing an ultrahigh molecular weight polyethylene (UHMWPE); providing a filler; providing a processing plasticizer; adding the filler to the UHMWPE in a mixture being in the range of from about 1:9 to about 15:1 filler to UHMWPE by weight; adding the processing plasticizer to the mixture; extruding the mixture to form a sheet from the mixture; calendering the sheet; extracting the processing plasticizer from the sheet to produce a matrix comprising UHMWPE and the filler distributed throughout the matrix; stretching the microporous material in at least one direction to a stretch ratio of at least about 1.5 to produce a stretched microporous matrix; and subsequently calendering the stretched microporous matrix to produce a microporous material which exhibits improved physical and dimensional stability properties over the stretched microporous matrix.