Interfacially synthesized reverse osmosis membrane, process for the preparation thereof and its use in a process for removing solute from solute-containing water

摘要

A sheet-like composite material comprising a microporous support layer and, supported thereon, a crosslinked, water permeable, interfacially polymerized, ultrathin polyamide desalinizing layer, characterised in that the desalinizing layer comprises the interfacial condensation reaction product of:(a) an essentially monomeric, aromatic amine-reactive reactant comprising a polyfunctional acyl halide, the amine-reactive acyl halide groups of the polyfunctional acyl halide being capable of condensing with primary amine functional groups to form amide linkages in less than 60 seconds under normal ambient temperature and pressure; which polyfunctional acyl halide has at least three of the acyl halide groups substituted on an aromatic nucleus comprising less than 3 aromatic rings; the amine-reactive reactant being at least 0.01 weight-% soluble in liquid aliphatic or liquid halogenated aliphatic solvents; the aromatic nucleus being free of substituents capable of chemical interference with inter- molecular amine-carboxylic acid, amide-forming condensation reactions; and(b) an essentially monomeric, aromatic, polyamine reactant having at least two primary-amine substituents substituted on an aromatic nucleus comprising less than 3 aromatic rings; the primary amine functionality of the said aromatic polyamine reactant being no more than the carboxylic acid equivalent functionality of said polyfunctional acyl halide; the aromatic polyamine reactant having a solubility in water of at least 0.01 % by weight and being free of substituents capable of chemical interference with intermolecular amine/carboxylic acid, amide-forming condensation reactions;the polyamide layer having a lower % elongation than the corresponding linear polymer; a molecular weight in excess of 100,000; a crosslink density of at least 1 per 100,000; a solubility in liquid organic amide, sulphoxide, and pyrrolidone solvents or solvent blends which is less than 10% by weight and a salt rejection capability, tested with simulated sea water under40 to70 atmospheres pressure and 25°C, of at least 85% at a flux of at least about 400 I/m²d.;The cross-linked polyamide desalinizing layer is preferably polymerised in situ on the microporous support layer.;The composite materials are useful for the removal of solute from solute-containing water.