Disclosed are self-assembled structures formed from self-assembling block copolymers, for example, a diblock copolymer of the formula (I): ##STR00001##
wherein R.sup.1-R.sup.4, n, and m are as described herein, which find use in preparing nanoporous membranes. In an embodiment, the block copolymer self-assembles into a cylindrical morphology. Also disclosed is a method of preparing such membrane which involves spin coating a polymer solution containing the block copolymer to obtain a thin film, followed by solvent annealing of the film. Further disclosed is a method of preparing porous membranes from the self-assembled structures.

Provided is a hydrophilic porous membrane including a porous membrane and a hydroxyalkyl cellulose (preferably, hydroxypropyl cellulose) retained in the porous membrane, the hydroxyalkyl cellulose having a weight-average molecular weight of 10,000 or more and less than 110,000. The hydrophilic porous membrane of embodiments of the invention has high water permeability and can pass an integrity test in the case of being used as a filtration membrane of a filter cartridge. Also provided is a method for producing the above-mentioned hydrophilic porous membrane, the method comprising causing a hydrophilizing liquid including 0.005% to 0.500% by mass of a hydroxyalkyl cellulose having a weight-average molecular weight of 10,000 or more and less than 110,000, to permeate a porous membrane.

Embodiments in accordance with the present invention encompass a composition comprising one or more of polycyclic olefinic monomers of formula (I) and one or more monomers of formula (III) for forming anion exchange membrane optionally in combination with one or more monomers of formula (II). The composition undergoes mass vinyl addition polymerization either under thermal or photolytic conditions and can be formed into ionomers on a suitable membrane support. The membrane supports thus formed are suitable as anion exchange membranes for fabricating a variety of electrochemical devices, among others. More specifically, the ionomeric membranes are formed on a variety of supports which contains a variety of quaternized amino functionalized norbornene monomeric units which are lightly crosslinked (less than five mol %). The membranes so formed exhibit very high ionic conductivity of up to 280 mS/cm at 80 C. The electrochemical devices made in accordance of this invention are useful as fuel cells, gas separators, and the like.

A filtration membrane includes a thermoplastic substrate, a first layer comprising a polysulfone, a polyvinylpyrrolidone, and a tetramine, and a second layer comprising the tetramine and reacted units of a phthaloyl chloride cross-linked to form a polyamide. A method of preparing the filtration membrane by impregnating tetramine in an ultrafiltration support matrix for rapidly fabricating a hyper-cross-linked polyamide membrane. The membrane prepared by the method of present disclosure can be used for nanofiltration.

A bipolar membrane comprising an anion exchange layer and a cation exchange layer, wherein the cation exchange layer is obtainable by curing a composition comprising: (a) a first crosslinking agent comprising an anionic group and at least two polymerisable groups; (b) a second crosslinking agent comprising at least 5 vinyl groups and being free from ionic groups; (c) a third crosslinking agent comprising 2, 3 or 4 polymerisable groups and being free from ionic groups.

A bipolar membrane comprising an anion exchange layer and a cation exchange layer, wherein the cation exchange layer is obtainable by curing a composition comprising: (a) a first crosslinking agent comprising an anionic group and at least two polymerisable groups; (b) a second crosslinking agent comprising at least 5 vinyl groups and being free from ionic groups; (c) a third crosslinking agent comprising 2, 3 or 4 polymerisable groups and being free from ionic groups.

A separation membrane includes a membrane comprising a polymer, characterized in that a functional layer is formed on the surface in one side of the membrane, the peak area percentage of carbon derived from ester group measured by the electron spectroscopy for chemical analysis (ESCA) on the surface of the preceding functional layer is 0.1% (by atomic number) or more but not more than 10 (% by atomic number), and the peak area percentage of carbon derived from ester group measured by the electron spectroscopy for chemical analysis (ESCA) on the surface opposite to the functional layer is not more than 10 (% by atomic number). A separation membrane module suffering from little sticking of organic matters, proteins, platelets and so on is provided with the separation membrane as a built-in membrane.

A separation membrane includes a membrane comprising a polymer, characterized in that a functional layer is formed on the surface in one side of the membrane, the peak area percentage of carbon derived from ester group measured by the electron spectroscopy for chemical analysis (ESCA) on the surface of the preceding functional layer is 0.1% (by atomic number) or more but not more than 10 (% by atomic number), and the peak area percentage of carbon derived from ester group measured by the electron spectroscopy for chemical analysis (ESCA) on the surface opposite to the functional layer is not more than 10 (% by atomic number). A separation membrane module suffering from little sticking of organic matters, proteins, platelets and so on is provided with the separation membrane as a built-in membrane.

A method for forming an isoporous graded film comprising multiblock copolymers and isoporous graded films. The films have a surface layer and a bulk layer. The surface layer can have at least 110.sup.14 pores/m.sup.2 and a pore size distribution (d.sub.max/d.sub.min)) of less than 3. The bulk layer has an asymmetric structure. The films can be used in filtration applications.

A method for forming an isoporous graded film comprising multiblock copolymers and isoporous graded films. The films have a surface layer and a bulk layer. The surface layer can have at least 110.sup.14 pores/m.sup.2 and a pore size distribution (d.sub.max/d.sub.min)) of less than 3. The bulk layer has an asymmetric structure. The films can be used in filtration applications.