High flux semipermeable membranes
First Claim
1. A semipermeable membrane having properties for providing increased flux while retaining salt rejection and chlorine resistance prepared by coating a porous support with an aqueous solution of an polyamine or bisphenol which contains a polar aprotic solvent not reactive with amines having properties for dissolving or plasticizing said support, removing excess of said solution, contacting the coated porous support with an organic solvent solution of an polyacyl halide, polysulfonyl halide, or polyisocyanate to form a reaction product within and/or on the surface of said porous support, and curing the resultant composite at curing conditions to form said high flux semipermeable membrane.
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Reexamination
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Abstract
High flux semipermeable membranes which comprise a polymerized reaction product within and/or on a porous support may be prepared by contacting the porous support such as a polysulfone sheet with an aqueous solution of an polyamine, said aqueous solution containing a polar aprotic solvent not reactive with amines and optionally an acid acceptor. The surface of the coated support is dried to the touch and then contacted with an organic solution of an polycarboxylic acid halide for a period of time sufficient to form a polymerized reaction product within and/or on the surface of the support material. The resulting composite may be post treated by washing with an alkaline compound. The resultant membrane composite may be used in separation processes such as the desalination of brackish or seawater, or the softening of domestic hard water.
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Citations
20 Claims
- 1. A semipermeable membrane having properties for providing increased flux while retaining salt rejection and chlorine resistance prepared by coating a porous support with an aqueous solution of an polyamine or bisphenol which contains a polar aprotic solvent not reactive with amines having properties for dissolving or plasticizing said support, removing excess of said solution, contacting the coated porous support with an organic solvent solution of an polyacyl halide, polysulfonyl halide, or polyisocyanate to form a reaction product within and/or on the surface of said porous support, and curing the resultant composite at curing conditions to form said high flux semipermeable membrane.
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19. A process comprising;
- preparing a semipermeable membrane providing increased flux while retaining salt rejection and chlorine resistance by coating on a porous support an aqueous solution of an aromatic polyamine which contains a polar aprotic solvent not reactive with amines having properties for dissolving or plasticizing said support and optionally an acid acceptor, removing excess solution, drying the surface of the coated support, contacting the dried surface of the coated support with an organic solution of an aromatic polycarboxylic acid halide to form a reaction product within and/or on the surface of said porous support and curing the resultant composite at curing conditions.
- View Dependent Claims (20)
Specification