Modified membranes
AssigneeSiemens Water Technologies Corp.
InventorHeinz-Joachim Muller
Life of this patent
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Abstract
A porous polymeric membrane formed from a blend of a polymeric membrane forming material, such as polyvinylidene fluoride or polysulfone and a polymeric reactivity modifying agent adapted to modify the surface active properties of the porous polymeric membrane. The reactivity modifying agent is preferably a linear polymeric anhydride, such as poly(alkyl vinyl ether/maleic anhydride). The surface activity modifications include modification of the hydrophilicity/hydrophobicity balance of the membrane, or hydrolysis followed by reaction with a polyamine to form a crosslinked polyamide layer. Such modified membranes have use as reverse osmosis membranes.
Claims42
A method of preparing a microporous polymeric membrane comprising the steps of:
- blending a polymeric membrane forming material and a reactivity modifying agent comprising polymeric anhydride in an amount such that a combined precursor to the microporous polymeric membrane forms a single phase mixture and thereby obtaining a blended material having between 3.1% and 3.4% polymeric anhydride;
- and
- casting the microporous polymeric membrane from the blended material.
A method of preparing a porous polymeric membrane, the method comprising the steps of:
- blending a polymeric membrane forming material and a polymeric anhydride into a single phase blended material;
- casting a porous polymeric membrane from the blended material;
- and
- chemically modifying at least a portion of the polymeric anhydride blended into the polymeric porous membrane forming material with one or more substances selected from the group consisting of tetraethylenepentamine, tris-(hydroxymethyl) aminomethane, sulfuric acid, polyethylene glycol, and calcium carbonate.
A method of modifying a surface of a microporous polymer membrane comprising the steps of:
- blending a reactivity modifying agent comprising a poly (methyl vinyl ether/maleic anhydride) with a polymeric membrane forming material, wherein the reactivity modifying agent is blended in an amount such that a combined precursor to the porous polymeric membrane forms a single phase mixture;
- and
- casting the microporous membrane.
A method of preparing a microporous polymeric membrane, comprising acts of:
- blending poly(methyl vinyl ether/maleic anhydride) and a polysulfone in an amount such that a combined precursor to the microporous polymeric membrane forms a single phase mixture and thereby obtaining a blended material;
- and
- casting the microporous polymeric membrane from the blended material.
A method of preparing a microporous polymeric membrane, comprising acts of:
- blending poly(methyl vinyl ether/maleic anhydride) and polyvinylidene fluoride in an amount such that a combined precursor to the microporous polymeric membrane forms a single phase mixture and thereby obtaining a blended material;
- and
- casting the microporous polymeric membrane from the blended material.
Dependencies are inferred from the claim text.