摘要:
The present invention relates to a nanofilter formed by using a porous ultrafiltration membrane as a precursor, and carefully controlling reaction conditions so as to maintain sufficient hydrophilic nature of the membrane while causing the pore structure to close to a nanofilter range (less than 400Daltons), This produces a solvent stable cellulose nanofiltration membrane capable of operating at satisfactory flux in aqueous solutions, and being low binding to organic biomaterials.
摘要:
Mixed matrix polymer membranes capable of separating carbon dioxide from mixtures including carbon dioxide and methane, and processes for purifying methane using the membranes include a selective layer thickness of between about 1000 Angstroms to about 0.005 inch, that include discrete carbon-based molecular sieve particles with sizes of between about 0.5 microns to about 5.0 microns. The particles are formed by pyrolyzing a precursor polymer in the form of a powder or film. The pyrolyzed polymer is then ideally milled to desired small size particles. The preferred ratio of particles to polymer is about 0.25 to about 1.0 by volume. A preferred method for preparing the mixed matrix membrane is by dispersing the particles in a solvent, adding a small quantity of the desired polymer, or 'sizing agent' to 'size' or 'prime' the particles, adding a polymer, casting a film of the polymer solution, and evaporating the solvent to form a mixed matrix membrane film. The polymer is preferably a rigid, glassy polymer, more preferably, with a glass transition temperature above about 150°C. The mixed matrix membrane is preferably in the form of a dense film or a hollow fiber.
摘要:
Compositions and methods for selectively binding metal ions from a source solution comprise using a polyhydroxypyridinone-containing ligand covalently bonded to a membrane support having the formula M-A-L(HOPO)n. M is a membrane having a hydrophilic surface, A is a covalent linkage mechanism, L is a ligand carrier, HOPO is a hydroxypyridinone appropriately spaced on the ligand carrier to provide a minimum of six functional coordination metal binding sites, and n is an integer of 3 to 6. The separation is accomplished by passing a source solution containing the ions to be separated through a cartridge containing the membrane-ligand composition, causing the selected ions to be complexed to the HOPO ligands and subsequently removing the selected ions from the cartridge by passing an aqueous receiving solution through the cartridge and quantitatively stripping the selected ions from the HOPO ligand.
摘要:
This invention provides a hydrophilic membrane wherein a hydrophilic cellulose derivative of a number average molecular weight of 2000∼8000 is adsorbed irreversibly to a hydrophobic membrane of an aromatic polymer. Since an amount of leaching substances is extremely small, the membrane can be used suitably in such fields as medical applications ,electronics, etc. where even a quite small quantity of leaching substances from the membranes is limited especially small.
摘要:
A method for bonding a porous medium (29) to the surface of a solid substrate (41) is disclosed. The method comprises positioning a dry porous medium (29) near a dry surface of a substrate (41) and impregnating the porous medium with a bonding composition by opening a valve (47) and allowing the bonding composition to pass through passageway (33) to groove (31). The impregnated porous medium (29) is maintained near the substrate surface (41) until the substrate surface is at least slightly dissolved in the bonding composition without dissolving the porous medium (29). At least a portion of the bonding composition is flushed through the impregnated porous medium (29) towards the substrate (41) and subsequently away from the surface of the substrate by opening of valve (44) at the adaptor (42) to a vacuum source (45). The bonding composition is then evaporated at a controlled rate from the substrate (41) and the porous medium (29).
摘要:
Verfahren zur Verbesserung der Biokompatibilität von cellulosischen Flachmembranen, dadurch gekennzeichnet, daß die Flachmembranen während oder nach der Herstellung mit Celluloseethern und/oder Celluloseestern und/oder Cellulosecarbamaten beschichtet werden, deren Strukturen den Formeln
entsprechen, worin Cell das Gerüst des unmodifizierten Cellulosemoleküls ohne Hydroxylgruppen ist und x dem Modifizierungsgrad entspricht, der im Bereich von 0,002 bis 3 liegt und worin R ein (gegebenenfalls substituierter) Alkyl- und/oder Alkenyl- und/oder Aryl- und/oder Arylalkyl-Rest ist und die Kohlenstoffkette des Restes R 1 bis 36 C-Atome enthält und durch Heteroatome wie O, S, N, unterbrochen sein kann und basische und/oder saure Gruppen wie -NR'₂, -COOR' und/oder -SO₃R' bzw. deren Salze enthält, wobei R'=H oder R ist.
摘要:
Provided are a hydrophilic porous membrane including a porous membrane and a hydroxyalkyl cellulose retained in the porous membrane, in which the average pore size differs between two surfaces of the porous membrane, the hydroxyalkyl cellulose distributed in the thickness direction of the hydrophilic porous membrane exhibits two or more peaks of detection intensity in GPC, and the weight-average molecular weight Mw min of the peak that is detected latest among the above-mentioned peaks is less than 100,000; and a method for producing a hydrophilic porous membrane, the method including separately preparing a hydrophilizing liquid including a hydroxyalkyl cellulose having a smaller weight-average molecular weight and a hydrophilizing liquid including a hydroxyalkyl cellulose having a larger weight-average molecular weight, and applying each of the hydrophilizing liquids on two surfaces of the porous membrane or sequentially on one surface thereof.