Described herein is a method of using hollow fiber filter cartridge. The method includes: providing a hollow fiber filter cartridge inside or outside an environmental cleaning equipment; allowing a wastewater to enter the hollow fiber filter cartridge from an outside of the hollow fiber filter under no water pressure or low water pressure (such as under 30 gw/cm.sup.2); allowing the wastewater to cross a plurality of nanopores of the hollow fiber filter cartridge under no water pressure or low water pressure (such as under 30 gw/cm.sup.2) to produce a clean water; and allowing the environmental cleaning equipment to filter wastewater to produce clean water continuously, thereby improving cleaning efficiency and reducing water consumption.

An object of the present invention is to provide a chemical liquid purification method by which a chemical liquid capable of inhibiting the occurrence of short in a semiconductor substrate manufactured by a photolithography process is obtained. Another object of the present invention is to provide a chemical liquid manufacturing method and a chemical liquid. The chemical liquid purification method of the present invention includes a purification step of filtering a liquid to be purified by using a filter, in which a filter satisfying a condition 1 or a condition 2 in the following test is used as the filter. Test: 1,500 ml of a test liquid formed of the organic solvent is brought into contact with the filter for 24 hours under a condition of 23° C., and a content of particles containing at least one kind of metal selected from the group consisting of Fe, Al, Cr, Ni, and Ti in the test liquid after the contact satisfies a predetermined condition.

An object of the present invention is to provide a chemical liquid purification method by which a chemical liquid capable of inhibiting the occurrence of short in a semiconductor substrate manufactured by a photolithography process is obtained. Another object of the present invention is to provide a chemical liquid manufacturing method and a chemical liquid. The chemical liquid purification method of the present invention includes a purification step of filtering a liquid to be purified by using a filter, in which a filter satisfying a condition 1 or a condition 2 in the following test is used as the filter. Test: 1,500 ml of a test liquid formed of the organic solvent is brought into contact with the filter for 24 hours under a condition of 23° C., and a content of particles containing at least one kind of metal selected from the group consisting of Fe, Al, Cr, Ni, and Ti in the test liquid after the contact satisfies a predetermined condition.

A porous membrane includes a triblock copolymer of the formula ABC. B is a hydrogenated vinyl aromatic block present in a range from 30 to 90 weight percent, based on the total weight of the copolymer and has a T.sub.g of ≥110° C. C is a rubbery block present in a range from 10 to 70 weight percent, based on the total weight of the copolymer and has a T.sub.g≤25° C. A is substantially incompatible with both the B and C blocks and is derived from ring-opening polymerization. B+C is present in a range from 70 to 95 weight percent, based on the total weight of the copolymer.

A porous membrane includes a triblock copolymer of the formula ABC. B is a hydrogenated vinyl aromatic block present in a range from 30 to 90 weight percent, based on the total weight of the copolymer and has a T.sub.g of ≥110° C. C is a rubbery block present in a range from 10 to 70 weight percent, based on the total weight of the copolymer and has a T.sub.g≤25° C. A is substantially incompatible with both the B and C blocks and is derived from ring-opening polymerization. B+C is present in a range from 70 to 95 weight percent, based on the total weight of the copolymer.

Ion exchange membranes obtainable by curing a composition comprising: (a) a monomer comprising an aromatic group and at least one polymerisable ethylenically unsaturated group; (b) a photoinitiator which has an absorption maximum at a wavelength longer than 380 nm when measured in one or more of the following solvents at a temperature of 23° C.: water, ethanol and toluene; and (c) at least one co-initiator.

Ion exchange membranes obtainable by curing a composition comprising: (a) a monomer comprising an aromatic group and at least one polymerisable ethylenically unsaturated group; (b) a photoinitiator which has an absorption maximum at a wavelength longer than 380 nm when measured in one or more of the following solvents at a temperature of 23° C.: water, ethanol and toluene; and (c) at least one co-initiator.

Cationic polymers are provided that comprise monomeric units of Formula (V). (V) Each asterisk (*) indicates an attachment position to another monomeric unit; R is hydrogen or methyl; each R.sup.2 is each independently an alkyl, aryl, or a combination thereof; L is a linking group comprising an alkylene group; and +R.sup.3 is a cationic nitrogen-containing group free of any N—H bonds. Membranes formed from said cationic polymers, devices including such membranes, and methods of making such cationic polymers are also provided.

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A functional polymer membrane having a pore volume fraction of 0.6% or more and 3.0% or less by allowing a reaction of curing a composition containing a polymerizable compound (A) and a copolymerizable monomer (B).

Provided are a methane-selective composite membrane comprising: a UiO-66 type organic-inorganic composite nanoporous material, a MIL-100 type organic-inorganic composite nanoporous material, or a ZIF-8 type organic-inorganic composite nanoporous material to which a methane-selective functional group is introduced for selectively separating methane from a gas mixture containing methane/nitrogen, a use thereof, and a method of preparing the same.