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US 11,883,784 B2Granted
Microporous membrane and methods to make same
AssigneeFresenius Medical Care Holdings, Inc.
InventorsPraveen Kosaraju, Monica P. Hall, Jiunn Teo
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AssigneeFresenius Medical Care Holdings, Inc.
InventorsPraveen Kosaraju, Monica P. Hall, Jiunn Teo
Estimating the term…
A method is disclosed for forming a microporous membrane that incorporates an additive having low water solubility at the membrane's active surface from a precipitation fluid. The incorporated additive at the membrane's active surface can improve one or more of the membrane's hydrophilicity, wettability, anti-fouling behavior, blood compatibility, and stability over long periods of use or repetitive use. The microporous membrane with this modified active surface can be a hollow fiber, flat sheet, or other self-supporting shape. The microporous membranes can be used for membrane filtering or a solute and/or solvent exchange process, which involve contacting aqueous-based fluid or blood with the microporous membrane, such processes for dialysis, blood oxygenation, or blood separation filtering, or other processes.
A microporous membrane comprising at least one non-active region and at least one active surface, wherein the at least one active surface includes a coating, and wherein the at least one non-active region and the at least one active surface each comprise at least one polymer, and the coating consists essentially of at least one additive, the at least one additive itself is a polymeric additive that has (i) low water solubility, (ii) hydrophilic properties, and (iii) solubility in a water-polar aprotic solvent mixture, and wherein the at least one additive of the coating is diffused towards the at least one non-active region such that a concentration of the at least one additive decreases in a direction from the at least one active surface towards the at least one non-active region.
A microporous membrane comprising at least one non-active region and at least one active surface, wherein the at least one active surface includes a coating and wherein the at least one non-active region and the at least one active surface each comprise at least one polymer, and the coating consists essentially of the polymeric at least one additive, the at least one additive itself is a polymeric additive and has (i) a water absorption from 20% up to 1000% of the weight of dry additive, and (ii) wherein the microporous membrane has a reduced blood platelet reduction relative to the microporous membrane without the at least one additive, and wherein the at least one additive of the coating is diffused towards the at least one non-active region such that a concentration of the at least one additive decreases in a direction from the at least one active surface towards the at least one non-active region.
Dependencies are inferred from the claim text.