COMPOSITE SEMIPERMEABLE MEMBRANE

• Main Author: HENN, ROBERT L
• Format: Patent
• Language: English; French
• Published: 24.09.1991
• Edition: 5
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING

COMPOSITE SEMIPERMEABLE MEMBRANE A composite semipermeable membrane is provided comprised of: (a) a flexible film of microporous hydrophobic material having a polar molecule vapour transmission rate in excess of 10,000 gms/m2 ? 24 hours, preferably above 100,000 gms/m2 ? 24 hours, and an advancing polar liquid contact angle exceeding 90 degrees, and (b) a continuous, crosslinked amorphous hydrophilic layer penetrated to an extent into the face of the hydrophobic layer. The hydrophilic layer, when appropriately located in the structure of the microporous hydrophobic material provides a composite membrane having a polar vapour transmission rate of the complete ensemble comparable to or even exceeding that of the hydrophobic material alone, and simultaneously offering two mechanisms of separation; that imposed by the microporous layer and that imposed by the continuous, dense amorphous polymer layer, and as such is capable of numerous separation operations.