Method for modifying the surface of a polymer membrane, and a membrane thus modified

Abstract

The present invention concerns a method for modifying the transfer characteristics of a porous organic or inorganic membrane, in which a) on the said membrane, at least one layer is formed by applying at least one homogeneous solution obtained by mixing one or more rare-earth or alkaline-earth fluoroalkoxides in an anhydrous organic solvent at room temperature and in an inert atmosphere, b) hydrolysis is effected by placing the coating formed at a) in contact with a quantity of water at least equal to the stoichiometric quantity required to hydrolyse the fluoroalkoxides, c) the membrane is rinsed with water to eliminate the soluble salts formed. The membranes thus modified are useful for the regeneration of photographic solutions, in particular black and white developers, or for the separation of organic compounds from aqueous effluents.

Dependencies are inferred from the claim text.