Disclosed is a hollow fiber that contains an outer layer made of a first polymer and an inner layer made of a second polymer, the inner layer including at its outer surface a macrovoid-free thin interface sublayer in contact with the inner surface of the outer layer. The first polymer is immiscible with the second polymer. Also disclosed is a process of preparing the above-described hollow fiber.

Disclosed is a hollow fiber that contains an outer layer made of a first polymer and an inner layer made of a second polymer, the inner layer including at its outer surface a macrovoid-free thin interface sublayer in contact with the inner surface of the outer layer. The first polymer is immiscible with the second polymer. Also disclosed is a process of preparing the above-described hollow fiber.

A hemofiltration device capable of surely performing highly-efficient hemofiltration. The hemofiltration device of the present invention is adapted to be implanted in a mammalian body for filtering blood, and includes a blood flow path layer having a blood flow path, a filtrate flow path layer having a filtrate flow path disposed along the blood flow path, and a filtration membrane interposed between the blood flow path layer and the filtrate flow path layer, for filtering the blood flowing through the blood flow path. A filtrate outlet of the filtrate flow path is provided at a position closer to a blood outlet than to a blood inlet of the blood flow path. The blood inlet, blood outlet, and filtrate outlet are provided only on one side or separately on opposite sides of a main body portion in the direction in which the layers are stacked.

A hemofiltration device capable of surely performing highly-efficient hemofiltration. The hemofiltration device of the present invention is adapted to be implanted in a mammalian body for filtering blood, and includes a blood flow path layer having a blood flow path, a filtrate flow path layer having a filtrate flow path disposed along the blood flow path, and a filtration membrane interposed between the blood flow path layer and the filtrate flow path layer, for filtering the blood flowing through the blood flow path. A filtrate outlet of the filtrate flow path is provided at a position closer to a blood outlet than to a blood inlet of the blood flow path. The blood inlet, blood outlet, and filtrate outlet are provided only on one side or separately on opposite sides of a main body portion in the direction in which the layers are stacked.

A method for coating a porous support with a thin membrane selective layer via interfacial free-radical polymerization. The method is carried out by immersing a porous support in a monomer-containing solution, removing the porous support from the solution, covering the porous support with a second solution immiscible with the first solution, the second solution containing a polymerization initiator, activating the initiator to effect polymerization of the monomer, and washing the porous support having the membrane selective layer. Also disclosed are membranes prepared by the method and filtration methods using the membranes.

A method for coating a porous support with a thin membrane selective layer via interfacial free-radical polymerization. The method is carried out by immersing a porous support in a monomer-containing solution, removing the porous support from the solution, covering the porous support with a second solution immiscible with the first solution, the second solution containing a polymerization initiator, activating the initiator to effect polymerization of the monomer, and washing the porous support having the membrane selective layer. Also disclosed are membranes prepared by the method and filtration methods using the membranes.

The invention relates to a process for recovering methane from digester biogas or landfill gas. More specifically, the invention pertains to biomethane production that substantially removes carbon dioxide from a digester biogas or landfill gas using first, second, and third purification stages each comprising one or more membranes selective for carbon dioxide over methane. A retentate from the first stage is separated by the one more membranes of the second stage into a second state retentate, forming a biomethane product gas. A permeate from the first stage is separated by the one or more membranes of the third stage into a third stage retentate and a third stage permeate. Recovery of methane from the the biogas is boosted by feeding the third stage retentate to the first purification stage. The recovery may be optionally further boosted by compressing the second stage permeate with the biogas at a main compressor.

The invention relates to a process for recovering methane from digester biogas or landfill gas. More specifically, the invention pertains to biomethane production that substantially removes carbon dioxide from a digester biogas or landfill gas using first, second, and third purification stages each comprising one or more membranes selective for carbon dioxide over methane. A retentate from the first stage is separated by the one more membranes of the second stage into a second state retentate, forming a biomethane product gas. A permeate from the first stage is separated by the one or more membranes of the third stage into a third stage retentate and a third stage permeate. Recovery of methane from the the biogas is boosted by feeding the third stage retentate to the first purification stage. The recovery may be optionally further boosted by compressing the second stage permeate with the biogas at a main compressor.

An article that can be used for biomaterial capture comprises

(a) a porous substrate; and

(b) borne on the porous substrate, a polymer comprising interpolymerized units of at least one monomer consisting of (1) at least one monovalent ethylenically unsaturated group, (2) at least one monovalent ligand functional group selected from acidic groups, basic groups other than guanidino, and salts thereof, and (3) a multivalent spacer group that is directly bonded to the monovalent groups so as to link at least one ethylenically unsaturated group and at least one ligand functional group by a chain of at least six catenated atoms.

An article that can be used for biomaterial capture comprises

(a) a porous substrate; and

(b) borne on the porous substrate, a polymer comprising interpolymerized units of at least one monomer consisting of (1) at least one monovalent ethylenically unsaturated group, (2) at least one monovalent ligand functional group selected from acidic groups, basic groups other than guanidino, and salts thereof, and (3) a multivalent spacer group that is directly bonded to the monovalent groups so as to link at least one ethylenically unsaturated group and at least one ligand functional group by a chain of at least six catenated atoms.