The problem is to provide a porous membrane with a reduced phenomenon in which membranes firmly adhere to one another during production of the porous membrane (membrane adhesion). The problem is solved by a porous membrane comprising a hydrophobic polymer and a hydrophilic polymer, wherein an average value T of ratios of the number of counts of ions derived from the hydrophilic polymer to the number of counts of ions derived from the hydrophobic polymer is 1.0 or more when a surface of the porous membrane is measured by time-of-flight secondary ion mass spectrometry (TOF-SIMS).

A tubular membrane, a membrane module, a device including a number of such membranes, and a method for manufacturing such membranes. The tubular membrane includes a tubular base providing a support and having an inner and outer surface, where the tubular base defines a lumen for the feed flow, and a membrane layer provided on the inner surface of the tubular base, where the inner surface of the tubular membrane includes a number of inwardly projecting ridges that extend in a substantially longitudinal direction of the tubular membrane.

A member of the present invention is to be placed to cover a ventilation hole in order to allow passage of gas between an outside and an inside of a housing through the ventilation hole of the housing and prevent dust and/or a liquid from entering the inside from the outside through the ventilation hole. The member of the present invention includes a porous membrane having air permeability in a thickness direction and a provisional protective film joined to the porous membrane to cover the porous membrane from the outside side. The provisional protective film is air-impermeable in a thickness direction or has lower air permeability in the thickness direction than the air permeability of the porous membrane. The provisional protective film and the porous membrane are joined to each other in such a manner that the provisional protective film is removable from the porous membrane.

Provided is a nanofiltration composite membrane, comprising: a supporting layer comprising a polyethylene terephthalate, a polymeric porous layer formed on the supporting layer, the polymeric porous layer comprising a polysulfone and an amphiphilic polymer represented by the formula below:

##STR00001##

and an interfacial polymerization layer formed on the polymeric porous layer and the interfacial polymerization layer comprising polyamide which is synthesized by polymerizing piperazine with 1,3,5-benzenetricarbonyl trichloride; wherein, n1, n2, n3, x, and y are integers greater than 0, the molecular weight of the amphiphilic polymer ranges from 90,000 to 200,000, and a weight ratio of the polysulfone to the amphiphilic polymer ranges from 2 to 20. The nanofiltration composite membrane can increase the removal rate of divalent ions and separate substances of specific molecular weights in solutions.

A membrane, for example a flat sheet membrane, has posts extending from a separation layer. The posts extend through one or more supporting structures such as a substrate layer and/or a permeate carrier, between two separation layers, or both. A post may help to attach the separation layer to a supporting structure, attach two supporting structures together, strengthen a supporting structure and/or attach two separation layers together. In some examples, one or more supporting structures, which may be temporary or remain in the membrane, are made with openings for posts. A liquid containing the separating layer material is cast over the supporting structure or structures and some of the liquid flows at least part way through the openings before the liquid is solidified. A temporary supporting structure may be removed, for example dissolved. In other examples, two supporting structures are held apart in a casting knife while posts are formed.

Provided is a composition for interfacial polymerizing polyamide including an amine compound; and one or more types of compounds selected from among a purine-based compound and a pyrimidine-based compound of Chemical Formula 1: ##STR00001## wherein, in Chemical Formula 1: X is N or NH; Y is O or OH; Z is O, OH or NH.sub.2; R1 and R2 are each hydrogen or a substituted or unsubstituted alkyl group; and is a single bond or a double bond, and a method for manufacturing a water-treatment membrane and a water-treatment membrane using the same.

The present invention provides enthalpy exchanger elements (E, E′) and enthalpy exchangers comprising such elements. Furthermore, the invention discloses a method for producing such enthalpy exchanger elements and enthalpy exchangers, comprising the steps of a) providing an air-permeable sheet element (1); b) laminating at least one side (1a, 1b) of the sheet element (1) with a thin polymer film (3, 4) with water vapor transmission characteristics; and c) forming the laminated sheet element (1) into a desired shape exhibiting a three-dimensional corrugation pattern (5, 5, . . . ).

The present invention provides: a gas separation method which is capable of desirably separating a slight amount of a component from a mixed gas under mild conditions such that the pressure difference between both sides of a gas separation membrane is 1 atmosphere or less; and a gas separation membrane which is suitable for use in this gas separation method. According to the present invention, in a gas separation method wherein a specific gas (A) in a mixed gas, which contains the specific gas (A) at a concentration of 1,000 ppm by mass or less, is selectively permeated with use of a gas separation membrane, an extremely thin gas separation membrane that has a film thickness of 1 μm or less is used, so that the gas (A) is desirably separated under mild conditions such that the pressure difference between both sides of the gas separation membrane is 1 atmosphere or less.

A filter material that contains a non-woven fabric is provided. When the amount of deformation of the filter material is 10 mm, its three-point bending strength is 2.0 MPa or greater.

Described herein are polymeric based composite membranes that provide selective resistance for gases while providing water vapor permeability. Such composite membranes have a high water/air selectivity in permeability. The methods for making such membranes and using the membranes for dehydrating or removing water vapor from gases are also described.