Metallopolyimide precursor fibers for aging-resistant carbon molecular sieve hollow fiber membranes having enhanced selectivity include transition metal cations complexed with electronegative regions of a polyimide. CMS membranes are made by pyrolyzing the metallopolyimide precursor fibers. The cations are introduced by including, in the spin dope composition used to extrude the fibers, either a salt of the transition metal and an inorganic anion or a transition metal/organic ligand complex.

A method for the manufacture of ceramic hollow fiber membranes in a spinning process by using a spinning mass, comprising the steps: providing a spinning mass formulation; providing a secondary phase; adding the secondary phase to the spinning mass formulation; manufacturing the ceramic hollow fiber membranes in a spinning process.

The present invention provides a porous hollow fiber membrane that has both high strength and high pure water permeability, and that exhibits excellent thermal deformation resistance. The present invention is related to a porous hollow fiber membrane containing a fluororesin-based polymer, and a manufacturing method of the membrane comprises a drawing step and a relaxing step. The porous hollow fiber membrane is characterized in that: the molecular chain of the polymer is oriented in the longitudinal direction of the hollow fiber membrane; and at the same time internal distortion of oriented non-crystalline chains, which is disadvantageous in terms of entropy, is alleviated.

The present invention relates to the use of additives in processes to form polymeric fibers. These fibers can be formed into membranes with improved middle and/or higher molecular weight solute removal.

The present disclosure relates to semipermeable membranes which are suitable for blood purification, e.g. by hemodialysis, which have an increased ability to remove larger molecules while at the same time effectively retaining albumin. The membranes are characterized by a molecular retention onset (MWRO) of between 9.0 kD and 14.5 kD and a molecular weight cut-off (MWCO) of between 55 kD and 130 kD as determined by dextran sieving curves and can be prepared by industrially feasible processes excluding a treatment with salt before drying. The invention therefore also relates to a process for the production of the membranes and to their use in medical applications.

The present disclosure relates to a dialyzer comprising a bundle of semipermeable hollow fiber membranes which is suitable for blood purification, wherein the dialyzer has an increased ability to remove larger molecules while at the same time it is able to effectively remove small uremic toxins and efficiently retain albumin and larger proteins. The invention also relates to using said dialyzer in hemodialysis.

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.

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.

Metallopolyimide precursor fibers for aging-resistant carbon molecular sieve hollow fiber membranes having enhanced selectivity include transition metal cations complexed with electronegative regions of a polyimide. CMS membranes are made by pyrolyzing the metallopolyimide precursor fibers. The cations are introduced by including, in the bore fluid used to extrude the fibers, either a salt of the transition metal and an inorganic anion or a transition metal/organic ligand complex.

The invention relates to polyimide membranes and to a phase inversion method for the production thereof. The polyimide membranes can be used to separate different gas mixtures.