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AssigneeThe Dow Chemical Company
InventorsThomas E. Davis, Donald L. Schmidt, Jee I. Kau, Ritchie A. Wessling, Sharon S. Whipple, Richard F. Fibiger, Dale M. Pickelman
Estimating the term…
A novel composite membrane and methods of making the membrane are described. The discriminating layer of the membrane is prepared by reaction of a reactive cationic compound group with a compound bearing a nucleophilic moiety. At least one of the reactants bears an average of two or more reactive groups. The reaction product contains covalent bonds formed via charge eliminating reactions. In a preferred embodiment of the invention, the nucleophilic group is anionic and a coacervate is formed initially on a microporous substrate. The resulting membrane may be useful for reverse osmosis, gas or ultrafiltration separations.
A supported, permselective membrane which comprises at leaset one permselective discriminating layer affixed to a supporting surface in a manner such that when the membrane is sealingly engaged to a vessel which defines a space communicating with a first surface of the membrane, components to which the membrane is permeable in a fluid mixture contacting the first surface of the membrane can permeate through the membrane to a second space, said membrane discriminating layer comprising a reaction product of a first compound bearing at least one reactive cationic moiety selected from the group consisting of sulfonium, quaternary ammonium, phosphonium, pyridinium, thiazolinium, imidazolinium, sulfoxonium, isothiouronium, azetidinium and diazonium with a second compound including at least one nucleophilic moiety reactive with said cationic group, with the proviso that the first compound must bear an average of more than one reactive cationic group, the second compound must bear an average of more than one reactive nucleophilic group or either the first or second compound must be polymerizable, said reaction product containing a plurality of covalent bonds created via extinction of a cationic charge.
Dependencies are inferred from the claim text.