INTEGRAL MULTI-LAYERED ION-EXCHANGE COMPOSITE MEMBRANES

摘要

The present invention provides a distinct advancement over presently known ion-exchange composite membranes, and the techniques for making such membranes. In one embodiment of the present invention, this is accomplished by a thin integral composite membrane comprised of a microporous polymer film, such as expanded polytetrafluoroethylene having a porous microstructure defined by polymeric fibrils, which provides a reinforcing support that supports an ion-exchange polymer resion or material on one side of the porous polymeric film and supports another different ion-exchange polymer resin on the other side. Thus, the invention uses two different ion-exchange resins on each side of a porous polymeric support film. By employing ionic exchange resins which differ in structure, functional groups or equivalent weight, or a combination of such, a wide variety of composites can be made and tailored to specific end uses.