Ultra-thin integral composite membrane
AssigneeW. L. Gore & Associates, Inc.
InventorsBamdad A. Bahar, Robert S. Mallouk, Alex R. Hobson, Jeffrey A. Kolde
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Abstract
An ultra-thin composite membrane is provided which includes a base material and an ion exchange resin. The base material is a membrane which is defined by a thickness of less than 1 mil (0.025 mm) 0.8 mils and a microstructure characterized by node interconnected by fibrils, or a microstructure characterized by fibrils with no nodes present. The ion exchange resin substantially impregnates the membrane such that the membrane is essentially air impermeable.
Claims51
An ultra-thin composite membrane comprising:
- (a) an expanded polytetrafluoroethylene membrane having a porous microstructure of polymeric fibrils and a total thickness of less than 0.025 mm 0.8 mils;
- and
- (b) an ion exchange material impregnated throughout the membrane, the impregnated expanded polytetrafluoroethylene membrane having a Gurley number of greater than 10,000 seconds, wherein the ion exchange material substantially impregnates the membrane to render an interior volume of the membrane substantially occlusive.
An ultra-thin composite membrane comprising:
- (a) a membrane having a porous microstructure of polymeric fibrils and a total thickness of less than 13 μm 0.51 mils;
- and
- (b) an ion exchange material impregnated throughout the membrane, the impregnated expanded polytetrafluoroethylene membrane having a Gurley number of greater than 10,000 seconds, wherein the ion exchange material substantially impregnates the membrane to render an interior volume of the membrane substantially occlusive.
An ion exchange membrane comprising:
- (a) a membrane comprising an expanded polytetrafluoroethylene having a porous microstructure defined substantially of only fibrils;
- and
- (b) an ion exchange material impregnated throughout the membrane, the impregnated expanded polytetrafluoroethylene membrane having a Gurley number of greater than 10,000 seconds, wherein the ion exchange material substantially impregnates the membrane to render an interior volume of the membrane substantially occlusive, said membrane having a total thickness within the range of between 0.06 mils and about 0.5 mils.
A composite, ultra-thin, substantially non-porous membrane consisting essentially of:
- (a) a polytetrafluoroethylene base having a pore structure defined by at least fibrils, said pore structure defining a porosity of at least 70% within said base;
- and
- (b) an ion exchange resin contained within said pore structure and substantially filling said pore structure, such that the composite membrane has a Gurley number which exceeds 10,000 seconds, said composite membrane having a thickness no greater than 0.8 mils.
A composite, substantially non-porous membrane consisting essentially of:
- (a) a polytetrafluoroethylene base having a pore structure defined by at least fibrils, said pore structure defining a porosity of at least 70% within said base;
- and
- (b) an ion exchange resin contained within said pore structure and substantially filling said pore structure, such that the composite membrane has a Gurley number which exceeds 10,000 seconds, said composite membrane having a thickness of at most 0.8 mils and an ionic conductance of at least 8.5 mhos/cm2.
A supported, composite membrane consisting essentially of:
- (a) a porous support material;
- and
- (b) a composite, ultra-thin, substantially non-porous membrane, said composite membrane having a polytetrafluoroethylene base having a pore network formed by at least fibrils, said pore network defining a porosity of at least 70% within said base;
- and
- (c) an ion exchange resin contained within said pore network and substantially filling said pore network, such that the composite membrane has a Gurley number which exceeds 10,000 seconds and said composite membrane has a thickness no greater than 0.8 mils.
A composite, ultra-thin, substantially non-porous membrane having a total thickness of at most 0.8 mils having a polytetrafluoroethylene base with a pore structure defining a porosity of at least 70% within said base, at least one ion exchange resin contained within said pore structure such that said composite membrane has a Gurley number which exceeds 10,000 seconds, and is prepared by the process comprising the steps of:
- (a) providing a polytetrafluoroethylene membrane having polytetrafluoroethylene base and a thickness of at most 0.8 mils and having a pore structure defining a porosity of at least 70% within said base;
- and
- (b) applying an ion exchange resin containing solution to each side of said polytetrafluoroethylene base to substantially fill said pore structure.
Dependencies are inferred from the claim text.