A hollow fiber porous membrane includes polyethersulfone or polysulfone. The hollow fiber porous membrane has an inner diameter from 300 to 600 μm, a thickness from 70 to 200 μm, a molecular weight cut-off of 10000 or lower, and a plurality of pores having a pore diameter from 0.1 to 0.5 μm throughout an outer surface; and a swelling rate of less than 5% as defined below: Swelling Rate (%): for 20 or more of the hollow fiber porous membranes, after a membrane thickness in a cross section of each one of the hollow fiber porous membranes in the width direction is measured at randomly selected 10 or more locations, an average membrane thickness is calculated based on 200 or more locations in total, and the swelling rate is calculated by a formula below: Swelling Rate (%)=(location numbers where the membrane thickness as measured exceeded 1.3 times the average membrane thickness)/(membrane thickness measurement numbers)×100.

A method of filtration includes a filtration step in which a liquid to be filtered is filtered through a porous membrane module consisted of a resin having a three-dimensional network structure by external pressure filtration; a cleaning step of cleaning an outer surface of the porous membrane by carrying out backwash of passing a cleaning solution through the porous membrane from an inner surface of the membrane, and air bubbling after the filtration step; and a discharging step of discharging the cleaning solution remaining on the outer surface and inside of the porous membrane after the cleaning step; and in SEM images of a membrane cross section in a membrane thickness direction orthogonal to the inner surface of the porous membrane, a total area of a resin portion having an area of 1 μm.sup.2 or less is 70% or more relative to a total area of the resin portion.

A spiral-wound type gas separation membrane element includes a central tube and a laminate wound around the central tube. Laminate includes at least one structure where a feed-side flow path member, a gas separation membrane, and a permeate-side flow path member are superimposed in this order. Permeate-side flow path member has a thickness of 400 μm to 1300 μm. Gas separation membrane is a membrane where a hydrophilic resin composition layer, a porous layer, and a permeate-side surface layer are superimposed in this order. Permeate-side surface layer faces Permeate-side flow path member and has a Young's modulus of 20 MPa to 400 MPa.

Provided herein are methods and systems pertaining to sequencing units of analytes using nanopores. In general, arresting constructs are used to modify an analyte such that the modified analyte pauses in the opening of a nanopore. During such a pause, an ion current level is obtained that corresponds to a unit of the analyte. After altering the modified analyte such that the modified analyte advances through the opening, another arresting construct again pauses the analyte, allowing for a second ion current level to be obtained that represents a second unit of the analyte. This process may be repeated until each unit of the analyte is sequenced. Systems for performing such methods are also disclosed.

Provided is a porous membrane which has a high water permeability performance, a high blocking performance, and a durability performance against loads of long-term and high operation pressures, which are suitable for filtering applications. The porous membrane includes one surface to be on a side of a filtrate; and the other surface to be on a side of a liquid to be filtered, wherein a surface pore diameter index of the one surface is 2.5 or more, the surface pore diameter index being determined by dividing a pore diameter in a top surface by a pore diameter in a second top surface.

The present invention relates to a separation membrane including a thermoplastic polymer selected from a cellulose ester and a polyamide, in which, when regions obtained by dividing a cross-sectional surface perpendicular to a longitudinal direction of the separation membrane into 5 at an equal interval are defined as regions 1 to 5, all the regions 1 to 5 have a number average pore diameter changing rate α.sub.i of −0.25 to 0.25, and at least one of the regions 1 to 5 is a region P that satisfies conditions (a) and (b): (a) a value of area average pore diameter D.sub.s/number average pore diameter D.sub.n is 2.50 to 6.00; and (b) a number average W of fine pores that are located at a distance smaller than L.sub.a from a center of respective coarse pores is 10 to 30.

Described are porous, sintered inorganic bodies that include multiple layers made from different types of metal particles, that may be useful as filter membranes, and also to methods of making and using the porous, sintered inorganic bodies.

In particles removal with extremely high filtration efficiency and the ability to block submicron airborne particles by a sieving mechanism is provided. This novel nanoporous filter advantageously combines extremely high transmittance for visible light and ultraviolet light, reusability after cleaning or disinfection by ultraviolet irradiation or simple washing, a customizable sieving pore size ranging from a few nanometers to 500 nanometers, and the ability to carry bactericidal, virucidal or other reagents or particles on the nano or micro scale.

A method of manufacturing a PVDF composite separation membrane according to an embodiment of the present disclosure has advantages in that it is possible to control the size of pores in various ways based on the nonsolvent-induced phase transition process and calcination process, and manufacture a porous high-strength PVDF composite separation membrane having high water permeability, and it is possible to manufacture a PVDF composite separation membrane which may exhibit durability that does not damage the membrane even under high pressure, while having heat resistance applicable even at a high temperature of 150° C., and excellent chemical resistance to acids and alkalis, and suppress heavy metal adsorption and biofouling phenomenon, and may allow an organic material to be decomposed by ultrasonic waves or UV photocatalysts. In addition, the PVDF composite separation membrane has excellent mechanical, thermal and chemical resistance properties, suppresses the biofouling phenomenon, and exhibits high ultrasonic reactivity.

The present invention relates to a reverse osmosis membrane and a method of preparing the same, and more particularly to a high durability reverse osmosis membrane which is excellent in interlayer bonding in a separation membrane while maintaining an equal flow rate as compared with a conventional reverse osmosis membrane to minimize a reduction in durability in the membrane upon backwashing to enhance a cleaning effect, prolong the life of a highpressure membrane, maximize the amount of accumulated treated water, and reduce maintenance costs, and a method of preparing the same.