Patent classifications
B01D2323/081
METHOD FOR PRODUCING POROUS HOLLOW FIBER MEMBRANE FOR HUMIDIFICATION
A method for producing a porous hollow fiber membrane for humidification, the method comprising dry-wet spinning a spinning dope comprising a water-soluble organic solvent solution composed of polyphenylsulfone resin and hydrophilic polyvinylpyrrolidone using water as a core liquid; then performing a crosslinking treatment at 120 to 220° C. for 1 to 20 hours; and then dipping the resultant in an acidic solution with a concentration of 5 to 500 ppm. The obtained porous hollow fiber membrane has improved hydrophilicity without impairing the wettability of the porous hollow fiber membrane. Since, humidification performance of the porous hollow fiber membrane alone can be improved, it is effective as a humidifying membrane for fuel cells.
Method of making carbon molecular sieve membranes
The invention is an improved method of making a carbon molecular sieve (CMS) membrane in which a polyimide precursor polymer is pyrolyzed to form a carbon molecular sieve membrane by heating, in a furnace, said polyimide precursor polymer to a final pyrolysis temperature of 600 C to 700 C at a pyrolysis heating rate of 3 to 7 C/minute from 400 C to the final pyrolysis temperature, the final pyrolysis temperature being held for a pyrolysis time of at most 60 minutes in a non-oxidizing atmosphere. In a particular embodiment, the cooling rate from the pyrolysis temperature is accelerated by methods to remove heat. The CMS membranes have shown an improved combination of selectivity and permeance as well as being particularly suitable to separate gases in gas streams such methane from natural gas, oxygen from air and ethylene or propylene from light hydrocarbon streams.
Perfluoropolymer hollow fiber composite membrane preparation method
A perfluoropolymer hollow fiber composite membrane preparation method includes the steps of (A) preparing a supporting layer of the perfluoropolymer hollow fiber composite membrane, (B) preparing a membrane casting solution, which includes obtaining a mixed solution by mixing a perfluoropolymer water dispersion emulsion, a spinning carrier and solvent, and defoaming the mixed solution at vacuum and a constant temperature, (C) preparing a nascent hollow fiber composite membrane, which includes compositing by uniformly coating the membrane casting solution on an outer surface of the supporting layer through an annular spinneret using chemical fiber concentric circle composite spinning technology, putting the supporting layer after compositing into a coagulant, solidifying and forming, and (D) drying after putting the nascent hollow fiber composite membrane to a hot air box, cleaning, sintering, and performing heat preservation. The prepared membrane has a thin wall, thermal and chemical resistance and good mechanical performance.
STERILIZABLE POROUS FILTRATION MEDIA CONTAINING NANOFIBER
Provided herein are sterilizable porous filtration media and methods of making and using the same.
POROUS POLYMERIC CELLULOSE PREPARED VIA CELLULOSE CROSSLINKING
The invention relates to porous polymeric cellulose prepared via cellulose crosslinking. The porous polymeric cellulose can be incorporated into membranes and/or hydrogels. In preferred embodiments, the membranes and/or hydrogels can provide high dynamic binding capacity at high flow rates. Membranes and/or hydrogels comprising the porous polymeric cellulose are particularly suitable for filtration, separation, and/or functionalization media.
FUNCTIONALIZED POLY(DIALLYLPIPERIDINIUM) AND ITS COPOLYMERS FOR USE IN ION CONDUCTING APPLICATIONS
The invention relates to membranes, monomers and polymers. The monomers can form polymers, which can be used for membranes. The membranes can be used in alkaline fuel cells, for water purification, for electrolysis, for flow batteries, and for anti-bacterial membranes and materials, as well as membrane electrode assemblies for fuel cells. In addition to the membranes, polymers and monomers and methods of using the membranes, the present invention also relates to methods of making the membranes, monomers and polymers.
Method of producing zeolite film
Provided is a method of producing a zeolite film continuously and efficiently. Zeolite is formed on a surface of a support using a method including: a first step of attaching zeolite fine crystals to a surface of a support; a second step of preparing synthetic gel for growing the fine crystals; a third step of putting the support and the synthetic gel into a reactor and performing hydrothermal synthesis; and a fourth step of cleaning the support subjected to the hydrothermal synthesis, in which in the third step, multiple containers arranged to be movable in a constant-temperature apparatus are each used as the reactor, the temperature and pressure for the hydrothermal synthesis is adjusted by the temperature and pressure in the constant-temperature apparatus, and the reaction time of the hydrothermal synthesis is adjusted by setting the time from when the reactor enters the constant-temperature apparatus to when the reactor exits the constant-temperature apparatus.
IMPROVED METHOD OF MAKING CARBON MOLECULAR SIEVE MEMBRANES
The invention is an improved method of making an improved carbon molecular sieve (CMS) membrane in which a precursor polymer (e.g., polyimide) is pyrolyzed at a pyrolysis temperature to form a CMS membrane that is cooled to ambient temperature (about 40° C. or 30° C. to about 20° C.). The CMS membrane is then reheated to a reheating temperature of at least 250° C. to 400° C. to form the improved CMS membrane. The CMS have a novel microstructure as determined by Raman spectroscopy. The improved CMS membranes have shown an improved combination of selectivity and permeance as well as stability for separating light hydrocarbon gas molecules such as C.sub.1 to C.sub.6 hydrocarbon gases (e.g., methane, ethane, propane, ethylene, propylene, butane, butylene).
Carbon membrane for fluid separation and method for manufacturing the same
The present invention provides a carbon membrane for fluid separation that can suppress the breakage of a carbon membrane installed in a separation module during a vacuum desorption step before permeation of a fluid or during permeation of a fluid. The present invention provides a carbon membrane for fluid separation including a porous carbon support and a dense carbon layer provided on the porous carbon support, wherein the porous carbon support has an R.sub.s value of 1.0 or less, where the R.sub.s value is an R value (peak intensity of D-band (1360 cm.sup.−1)/peak intensity of G-band (1580 cm.sup.−1)) calculated from a Raman spectrum.
Porous polymeric cellulose prepared via cellulose crosslinking
The invention relates to porous polymeric cellulose prepared via cellulose crosslinking. The porous polymeric cellulose can be incorporated into membranes and/or hydrogels. In preferred embodiments, the membranes and/or hydrogels can provide high dynamic binding capacity at high flow rates. Membranes and/or hydrogels comprising the porous polymeric cellulose are particularly suitable for filtration, separation, and/or functionalization media.