Abstract: Membranes for hemodialysis prepared from polycarbonate materials have superior transport properties for middle molecular weight molecules than do cellulosic membranes while maintaining approximately the same ultrafiltration rate as cellulosic membranes. A percentage of patients treated using dialysers containing polycarbonate membranes show improved hematocrit and neurobehavioral functions.

Abstract: Polymers from the group consisting of cellulose and its ester and ether derivatives, of polyvinyl alcohol and its ester derivatives, copolymers with vinyl esters and homopolymers and copolymers of acrylates and methacrylates are modified with monofunctional or difunctional cyclic .beta.-ketonic acids or their esters, in particular with succinylsuccinic acid or its ester derivatives. The modified polymers are particularly suitable for obtaining semi-permeable membranes for osmotic separation methods.

Abstract: A semipermeable composite membrane comprising a thin semipermeable film of a polymeric material deposited on one side of a microporous substrate, said polymeric material being prepared by crosslinking a soluble polymer containing at least 30 mole % of a recurring unit of the formula ##STR1## wherein all symbols are as defined in claim 1, and having at least 0.2 milliequivalent, per gram of said polymer, of an amino group containing 1 or 2 active hydrogen atoms, with a polyfunctional compound containing at least two functional groups capable of reacting with the amino group having 1 or 2 active hydrogen atoms; and a process for preparing the same. The semipermeable composite membrane of this invention is especially useful for desalination of saline or brackish water by reverse osmosis.

Abstract: Membrane forming polymers are converted to hydrophilic polymeric membranes by (a) grafting a polyoxyethylene chain to a membrane forming polymer structure and thereafter forming a membrane; (b) coating a membrane with a polymer to which a polyoxyethylene chain has been grafted; or (c) grafting in situ a polyoxyethylene chain to a formed membrane polymer.

Abstract: Process for the control of bacterial growth in polyamide reverse osmosis membranes by treatment with iodide, hydrogen peroxide, or hydrogen peroxide derivatives.

Abstract: Good salt rejection and flux characteristics can be obtained with reverse osmosis membranes made from crosslinked, interfacially polymerized aromatic polyamides, particularly poly(arylenepolyamine aromaticpolycarboxylamides) such as poly(phenylenediamine trimesamide). The aromatic polyamides are preferably synthesized directly from an essentially monomeric polyacyl halide (at least tri- or higher in acyl functionality) and an essentially monomeric arylene polyamine with a measurable water solubility. As compared to closely analogous linear polymers, these interfacially polymerized, crosslinked polyamides have a lower % elongation and lower solubility (e.g. in amide solvents). Chlorine resistance characteristics of these polyamides are also good and can be improved by treatment with a chlorinating agent. In the preferred practice of the method for making a reverse osmosis membrane, a porous support layer is coated with the polyamine component (e.g.

Abstract: A method for the preparation of a semipermeable membrane which comprises exposing porous shaped articles of polyacrylonitrile or copolymers thereof containing acrylonitrile in an amount of more than 40% by mole to a plasma.The resulting semipermeable membrane is very useful for separating substances by reverse osmosis or ultrafiltration.

Abstract: A permselective membrane comprising a thin permselective film of a polymeric material, said polymeric material being prepared by cross-linking a polyaddition product between a polyepoxy compound and a polyamino compound having at least two amino groups capable of reacting with epoxy groups with a polyfunctional compound selected from the group consisting of aromatic, heterocyclic and alicyclic compounds containing at least two functional groups selected from acid halide, sulfonyl halide, isocyanate and acid anhydride groups; and a process for producing the same. The permselective membrane of this invention is especially useful for desalination of saline or brackish water by reverse osmosis.

Abstract: A composite permselective membrane is prepared by reaction of a film or layer containing cycloaliphatic polyfunctional secondary amines with a triacyl halide or its mixture with a diacyl halide. The membrane is useful in separating components of fluid mixtures or solutions, such as the removal of salts from aqueous solutions by reverse osmosis.

Abstract: A disulphimide group-containing acrylonitrile copolymer semi-permeable membrane which comprises:(A) from 99 to 50% by weight of acrylonitrile units;(B) from 1 to 50% by weight of units of an acrylonitrile-copolymerizable ethylenically unsaturated monomer containing one or two disulphimide groups; and(C) from 0 to 30% by weight of units of one or more other acrylonitrile-copolymerizable olefinically unsaturated monomer, the sum of the percentages amounts to 100.The semi-permeable membranes may be used in reverse osmosis and ultrafiltration.

Abstract: Novel membranes having two or more coatings of polyelectrolytes with at least one oppositely charged adjacent pair of coatings separated by a neutral layer to reduce charge neutralization, their method of preparation, and use for rejecting ionically charged solutes.

Abstract: Mixtures of approximately equivalent amounts of (a) a glycidylated hydantoin and (b) a mononuclear phenol with 2 or 3 phenolic hydroxyl groups, at least one of the components (a) or (b) being trifunctional. They additionally contain a curing accelerator and on heating form mechanically good and flexible plastics which are stable to hydrolysis and can be used as building materials and foams, for the finishing and coating of textile material and for the preparation of water-permeable membranes.

Abstract: A process for preparing a semipermeable membrane, which comprises contacting a thin polyamine film applied to a liquid-permeable microporous substrate with a polyalicyclic diisocyanate or polyalicyclic dicarbonyl halide capable of reacting with the amino or imino groups in the polyamine, thereby to crosslink the polyamine at the surface portion of the thin film.

Abstract: A semipermeable composite membrane comprising a thin semipermeable film of a polymeric material deposited on one side of the microporous substrate, said polymeric material being prepared by interfacial crosslinking of a polymer containing a recurring unit of the formula ##STR1## wherein each of R.sub.1 and R.sub.2 represents a hydrogen atom or a methyl group, and W.sub.1 represents a direct bonding or a sulfonyl group (--SO.sub.2 --), with a polyfunctional compound containing at least two functional groups selected from acid halide, sulfonyl halide, isocyanate, N-haloformyl, haloformate and acid anhydride groups; and a process for producing the same. The semipermeable composite membrane of this invention is especially useful for desalination of saline or brackish water by reverse osmosis.

Abstract: Semipermeable membranes useful in membrane separation processes are formed from a hydrophilic polyamide which is a block copolymer of nylon and a poly(dioxa-amide) such as poly(4,7-dioxadecamethylene adipamide).

Abstract: A specific porous membrane is found to be extremely useful for permeation-separation of an oil from an oil-containing emulsion. By contacting a stable oil-containing emulsion of either water-in-oil type or oil-in-water type with the surface of a specific porous membrane having at its surface a critical surface tension of less than 35 dynes/cm to not less than 20 dynes/cm and having an average pore diameter of 0.03 .mu.m to 5 .mu.m, a pore radius distribution of not more than 1.5 and a porosity of 1 to 85%, only the oil can be permeation-separated, without permeation of the liquid immiscible with the oil, with high selectivity and high oil permeation.