Abstract: The invention relates to a combined method for gentle molecular surface functionalisation of the very thin, selectively-acting separating layer which preferably consists of aromatic polyamides, polyurethanes and/or polyureas, of thin-film composite membranes for reverse osmosis (hyperfiltration) and for nanofiltration, subsequently collectively termed water-filtration membranes, in order to achieve a passive antifouling effect without impairing the selectivity of the water-selective separating layer made of polyamides and the water-permeability of the membrane.

Abstract: The invention relates to a combined method for gentle molecular surface functionalisation of the very thin, selectively-acting separating layer which preferably consists of aromatic polyamides, polyurethanes and/or polyureas, of thin-film composite membranes for reverse osmosis (hyperfiltration) and for nanofiltration, subsequently collectively termed water-filtration membranes, in order to achieve a passive antifouling effect without impairing the selectivity of the water-selective separating layer made of polyamides and the water-permeability of the membrane.

Abstract: The invention relates to processes for the preparation of free-flowing end products of strongly acidic cation exchangers. In the case of the strongly acidic cation exchangers prepared by the processes described in Patent Application P 195 48 012.0, the particle beds of the end products are not free-flowing. By additions of wetting agents or water-soluble initiators or surfactants in the polymerization stage or after the filtration of the end product and/or process engineering means, a permanent or temporary free flowability of the particle beds of the strongly acidic cation exchangers is achieved using the following processes. 1. By additions of known wetting agents in amounts of 0.25 g/l of aqueous phase or water-soluble initiators in amounts of 0.05 to 20 g/l of aqueous phase to the copolymerization system 20 minutes to 120 minutes after reaching the gel point. 2. By treatment of the strongly acidic cation exchangers with aqueous solutions of surface-active substances having a content of 0.

Abstract: Sulfonated strongly acidic cation exchangers are rendered free-flowing by treatment with wetting agents or water soluble initiators, washing with water at temperatures of at least 60° C. and heat drying.