A hollow fiber carbon membrane is produced by preparing a membrane-forming dope for carbon membranes by dissolving polyphenylene oxide in an amount giving a concentration of 15 to 40 wt. % in the membrane-forming dope, and sulfur in an amount giving a ratio of 0.2 to 3.0 wt. % based on the polyphenylene oxide, in a solvent capable of dissolving these components; preparing the membrane-forming dope for carbon membranes into a hollow shape by means of a spinning method in accordance with a non-solvent induced separation method using a double annular nozzle; performing a crosslinking treatment at 200 to 240? C. in the air; then performing an infusibilization treatment by heating at 250 to 350? C.; and further performing a carbonization treatment by heating at 450 to 850? C. in an inert atmosphere or under vacuum.

An electrolyte membrane is prepared from a liquid composition comprising at least one member selected from the group consisting of trivalent cerium, tetravalent cerium, bivalent manganese and trivalent manganese; and a polymer with a cation-exchange group. The liquid composition is preferably one containing water, a carbonate of cerium or manganese, and a polymer with a cation-exchange group, and a cast film thereof is used as an electrolyte membrane to prepare a membrane-electrode assembly. The present invention successfully provides a membrane-electrode assembly for polymer electrolyte fuel cells being capable of generating the electric power in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas, and being capable of stably generating the electric power over a long period of time.

A membrane-forming dope for carbon membranes, comprising polyphenylene oxide in an amount giving a concentration of 15 to 40 wt. % in the membrane-forming dope, and sulfur in an amount giving a ratio of 0.1 to 5.0 wt. %, preferably 0.2 to 3.0 wt. %, of the total weight of the polyphenylene oxide and the sulfur, both of which are dissolved in a solvent that can dissolve these components. A hollow fiber carbon membrane is produced by molding the membrane-forming dope for carbon membranes in a hollow shape by means of a wet or dry-wet spinning method using a double tubular nozzle, subjecting the molded product to an infusibilization treatment by heating at 150 to 350? C. in the air, and then subjecting it to a carbonization treatment by heating at 600 to 800? C. in an inert atmosphere or under vacuum. When the product molded in a hollow shape by means of a wet or dry-wet spinning method is subjected to an infusibilization treatment by heating in the air while stretching the product with a stress of 0.002 to 0.005 MPa, a hollow fiber carbon membrane having excellent gas permeability and a further high gas separation factor (He/CH.sub.4) can be obtained.

The invention provides a high permeance and high selectivity facilitated transport membrane comprising a very small pore, nanoporous polyethersulfone (PES)/polyvinylpyrrolidone (PVP) blend support membrane, a hydrophilic polymer inside the very small nanopores on the skin layer surface of the support membrane, a thin, nonporous, hydrophilic polymer layer coated on the surface of the support membrane, and metal salts incorporated in the hydrophilic polymer layer coated on the surface of the support membrane and the hydrophilic polymer inside the very small nanopores, a method of making this membrane, and the use of this membrane for olefin/paraffin separations, particularly for propylene/propane and ethylene/ethane separations.

The method relates to the modification of mineral adsorbent particularly halloysite in the form of clay or tube using dendritic polymer for treating wastewater containing ionic or nonionic water pollutants such as heavy metal ions, dyes, surfactants, high molecular weight coagulants and mineral oils. The method will increase surface activity of the adsorbent and can be applied to create positive or negative charges on the surface of the adsorbent. The modified mineral can be used as: adsorbent of pollutant such as dye, heavy metal ion, aromatic material from aqueous solutions, for removal of cations from aqueous solutions, for removal of anions from aqueous solutions, as filler in nano-composite, as nano-particle in polymeric membrane, adsorbent for soil, and special pharmaceutical application.

The present invention provides an ultrafiltration membrane comprising a sulfone polymer membrane matrix with pores and an organic polymer sealing layer, wherein the pores are filled with nanoadsorbents. The present invention further provides a method for preparing the ultrafiltration membrane, which includes the following steps: (1) synthesizing nanoadsorbents; (2) preparing the sulfone polymer membrane matrix by immersion-precipitation phase inversion; and (3) immobilizing nanoadsorbents in the pores of the sulfone polymer membrane matrix by reverse filling, then sealing the pores with organic polymers to form a multifunctional ultrafiltration membrane. In the present invention, colloidal gold, polyethylene glycol molecules and Pb(II) ions (and so forth) are utilized as models of viruses, macromolecular organic pollutants, and small molecular pollutants, respectively. It is shown that the multifunctional ultrafiltration membrane allows for removal of multiple pollutants from water and can simultaneously remove multiple pollutants under low pressure.

A method for preparing a polygraphene membrane includes adding graphite and sodium nitrate into sulfuric acid to form a first mixture; adding potassium permanganate solution into the first mixture to form a second mixture; adding hydrogen peroxide solution to the second mixture to form a mixture including soluble manganese ions; filtering the mixture including soluble manganese ions to form an aqueous suspension; centrifuging the aqueous suspension; performing ultrasonication of the suspension to obtain graphene oxide sheets; acylating the graphene oxide sheets to prepare an acylated graphene oxide sheet; and polymerizing the acylated graphene oxide sheets to prepare polygraphene.

A method for preparing a polygraphene membrane includes adding graphite and sodium nitrate into sulfuric acid to form a first mixture; adding potassium permanganate solution into the first mixture to form a second mixture; adding hydrogen peroxide solution to the second mixture to form a mixture including soluble manganese ions; filtering the mixture including soluble manganese ions to form an aqueous suspension; centrifuging the aqueous suspension; performing ultrasonication of the suspension to obtain graphene oxide sheets; acylating the graphene oxide sheets to prepare an acylated graphene oxide sheet; and polymerizing the acylated graphene oxide sheets to prepare polygraphene.

A method for preparing a polygraphene membrane includes adding graphite and sodium nitrate into sulfuric acid to form a first mixture; adding potassium permanganate solution into the first mixture to form a second mixture; adding hydrogen peroxide solution to the second mixture to form a mixture including soluble manganese ions; filtering the mixture including soluble manganese ions to form an aqueous suspension; centrifuging the aqueous suspension; performing ultrasonication of the suspension to obtain graphene oxide sheets; acylating the graphene oxide sheets to prepare an acylated graphene oxide sheet; and polymerizing the acylated graphene oxide sheets to prepare polygraphene.

A method for preparing a polygraphene membrane includes adding graphite and sodium nitrate into sulfuric acid to form a first mixture; adding potassium permanganate solution into the first mixture to form a second mixture; adding hydrogen peroxide solution to the second mixture to form a mixture including soluble manganese ions; filtering the mixture including soluble manganese ions to form an aqueous suspension; centrifuging the aqueous suspension; performing ultrasonication of the suspension to obtain graphene oxide sheets; acylating the graphene oxide sheets to prepare an acylated graphene oxide sheet; and polymerizing the acylated graphene oxide sheets to prepare polygraphene.