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US 5,028,337 AGranted
Coated membranes
AssigneeAligena AG
InventorsCharles Linder, Mara Nemas, Mordechai Perry, Reuven Ketraro
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Abstract
Composite membranes are provided comprising an underlying membrane selected from the group consisting of microfiltration, ultrafiltration and reverse osmosis membranes; and a coating thereon comprising at least one member selected from the group consisting of polyaromatic polymers and sulfonated poly(haloalkylenes), which has been subjected to a post-coating crosslinking treatment. These coated membranes are useful for various separation processes, especially in the food industry.
Claims44
A composite membrane which comprises
- an underlying membrane selected from the group consisting of microfiltration, ultrafiltration and reverse osmosis membranes;
- and a coating thereon comprising at least one member selected from the group consisting of aromatic oxide polymers containing halomethyl groups, aromatic polysulfones containing halomethyl groups, aromatic polyether sulfones containing halomethyl groups, aromatic polyether ketones containing halomethyl groups, and halomethyl group containing arylalkene homopolymers and copolymers, aromatic oxide polymers containing halomethyl and quaternized tertiary aminomethyl groups, aromatic polysulfones containing halomethyl and quaternized tertiary aminomethyl groups, aromatic polyether sulfones containing halomethyl and quaternized tertiary aminomethyl groups, aromatic polyether ketones containing halomethyl and quaternized tertiary aminomethyl groups, halomethyl and quaternized tertiary aminomethyl groups containing arylalkene homopolymers and copolymers, sulfonated polyaromatic polymers and sulfonated poly(haloalkylenes), which has been provided with properties of minimal salt rejection by being subjected to a post-coating crosslinking treatment comprising at least one of (i) heating and (ii) treatment with at least one member selected from the group consisting of polyfunctional amines, polyfunctional thiols and chlorosulfonation agents.
A process comprising:
- separating at least one member selected from the group consisting of insoluble particles, colloidal particles and solute molecules from an organic solvent, which further comprises contacting said solvent containing at least one said member under a superatmospheric pressure greater than the osmotic pressure with:
- a membrane having properties of minimal salt rejection which comprises at least one member selected from the group consisting of crosslinked acrylonitrile homopolymers and copolymers, and crosslinked substituted acrylonitrile homopolymers and copolymers;
- and thereafter recovering the thus treated solvent.
A process comprising:
- separating by retention at a membrane having properties of minimal salt rejection of at least one member of high molecular weight selected from the group consisting of insoluble particles, colloidal particles and soluble polymers from aqueous media, while permitting the passage therethrough of any dissolved salts and organic compounds having a molecular weight less than 5000, which further comprises contacting said media containing at least one said member under a superatmospheric pressure greater than the osmotic pressure with:
- a membrane which comprises at least one member selected from the group consisting of crosslinked acrylonitrile homopolymers and copolymers, and crosslinked substituted acrylonitrile homopolymers and copolymers;
- and thereafter recovering the thus treated media.
Dependencies are inferred from the claim text.