Processes for making membranes
OwnerJoseph P. Dankeseinventor
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Abstract
An improved process for modifying the properties of membranes, particularly ion exchange membranes, and novel membranes characterized by a unique combination of low gas permeability and low electrical resistivity. The process comprises the steps of modifying the morphology of a pre-membrane by subjecting it to a chemical reaction, advantageously with a reactive macromolecular solute in an organic solvent.
Claims24
A process for making an improved polymeric ion exchange membrane comprising the steps of treating an original polymeric membrane in a solution of polymeric solute, expanding the original membrane structure, removing, by action of said solution, a portion of said original membrane structure, and infusing at least some solute polymer from said solution into said expanded membrane structure.
A process for making an improved polymeric ion exchange membrane by enhancing the electrical conductivity and the water-bearing capacity thereof while decreasing the permeability of said membrane to fluids, said process comprising the steps of
- (a) treating an ion exchange membrane in a solution of polymeric solute in a solvent, said solution forming a means to remove some polymeric material from said membrane, said treatment being carried out long enough to expand the original membrane structure and remove some said polymeric material by action of said solution and
- (b) washing said membrane.
Dependencies are inferred from the claim text.