Abstract: Solutions of sulphonated polyaryletherketones in a solvent mixture of at least three liquids or low melting solids which are non-solvents or poor solvents for the polymer, can be used to produce asymmetric semi-permeable membranes. The polymer may be a polymer of--Ph.sup.1 --O--Ph.sup.2 --O--Ph.sup.1 --CO--and optionally--Ph.sup.1 --O--Ph.sup.1 --CO--and--Ph.sup.1 --O--Ph.sup.1 --O--Ph.sup.1 13 COp13 p0wherein Ph.sup.1 and Ph.sup.2 are respectively unsulphonated and sulphonated phenylene residues. The components of the solvent mixture have specified solubility parameters. A suitable solvent mixture is one formed from water, 1,4-dioxane and acetonitrile.

Abstract: There is disclosed a novel porous hollow fiber membrane which is characterized by such a unique porous structure that the inner and outer membrane surfaces have an in-a-plane average pore diameter of 0.01 to 10 .mu.m and the porous membrane wall has an in-a-plane porosity of not less than 10% measured in every plane perpendicular to a radial direction of the annular cross-section of the hollow fiber membrane, wherein the in-a-plane porosity exhibits at least one minimum value between the inner and outer membrane surfaces. The present porous hollow fiber membrane has been found to be especially useful for the removal of a virus from an aqueous protein solution containing a virus. A virus can be effectively removed from an aqueous protein solution with not only an extremely high virus removal percentage but also an extremely high protein permeability, without causing the protein to be denatured.

Abstract: Concentration of aqueous solutions of ethylene glycol may be effected by a composite membrane including a glutaraldehyde--crosslined polyvinyl alcohol bonded to a porous layer of polysulfone on a polyester backing.

Abstract: Saline water containing a chlorine-containing compound in the form of free chlorine, hypochlorite, etc. which has been added as a disinfectant or antibacterial compound is desalinated by passing the saline water through a semipermeable membrane which is resistant to the chlorine. The saline water is passed through this membrane at a temperature in the range of from ambient to about 50.degree. C. and a pressure in the range of from about 1380 to about 6895 kPA (200-1000 psi). The chlorine-resistant semipermeable membrane comprises an interfacial polymerized condensation reaction product composited on a porous backing support material which has been prepared by contacting a porous support material such as polysulfone with a solution of a diaryl methylene monomer containing at least one amine radical on each aryl nucleus.

Abstract: An apparatus and process for removing corrossive contaminants from a hydrocarbon including the steps of mixing water with a hydrocarbon contaminated with corrossive ions into a mixture and conducting the flow of the mixture tangentially relative to a surface of a plurality of microporous hydrophobic hollow fiber membranes and separating a permeate flow of decontaminated hydrocarbon from retentate mixture. An apparatus (10) is provided for this separation process which includes a mechanism for removing resistance to flow through the hollow fiber membrane (16) aiding in increased uniform tangential flow through the membrane (16).

Abstract: A process for producing aluminum hydroxide product having an improved level of whiteness is disclosed. In the process, a caustic solution having dissolved aluminum hydroxide is subjected to purification to remove color producing humate material. Purification includes passing the caustic solution through a semi-permeable membrane. The solution purified of humate material is treated to precipitate aluminum hydroxide therefrom.

Abstract: Membranes of highly crystalline PTFE having an average pore size between about 0.01 micron and about 0.5 micron ordinarily reject any passage of water while allowing an organic nonpolar liquid to flow therethrough. By thoroughly wetting an expanded polytetrafluroethylene membrane with isopropyl alcohol, such a membrane will selectively allow the passage of a polar liquid, for example water, therethrough while rejecting other components, including nonpolar organic liquids, such as oil, kerosene or the like, and dissolved components of fairly large molecular size. Such IPA-wetted membranes are used to separate oil-water mixtures by allowing the water to selectively permeate through the membrane. The membrane may include a 5 mil thick backing layer of nonwoven synthetic fibers. The mixture is supplied to the membrane at a pressure not greater than about 90 psig., and often very low pressures of about 5-20 psig. can be used.

Abstract: Semipermeable membranes of a porous polymeric substrate whose external and all internal surfaces (pores) are encapsulated by a semipermeable thin film of a hydrophilic polymer are provided. The encapsulating film consists of at least one layer of said polymer which is cross-linked/stabilized by polyfunctional compounds containing at least two functional (reactive) groups. The membrane substrate is optionally pretreated--before the encapsulation step--with polyfunctional compounds. The new membranes can be used in ultrafiltration and reverse osmosis processes. They are solvent-, pressure- and temperature-resistant and show good separation capacities, e.g. for separating organic compounds from salt solutions.

Abstract: A reverse osmosis process is described for removing alcohols from hydrocarbons, in the additional presence of ethers. Depending on the nature of the membrane used, the methanol can be selectively removed as the membrane permeate or retained as the membrane concentrate. The membrane may be made from cellulose esters, polyethylene, polyvinylchloride, polyvinylidene chloride-polyvinyl chloride, etc.

Abstract: There is disclosed a process for purifying/decolorizing dyeing wastewaters that have been adjusted in a pretreatment step to a pH in the range from 4 to 9 by addition of acid or alkali by means of a membrane separation process. The concentrate obtained after the first step is further decolorized and deionized in the second step. The permeate of the second step is recycled to the pretreatment step, while the permeate of the first step and the concentrated wastewater obtained after the second step are disposed of in conventional manner.

Abstract: Semipermeable composite membranes containing on one surface of a porous support a superficial thin film having semipermeable properties. The film contains polyvinyl alcohol (PVA)/polyvinyl alcohol-copolymers (PVA-copolymers) modified by at least radicals containing ionizable groups are provided. The modification steps comprise e.g. reacting PVA/PVA-copolymer films with(a) a monomeric organic compound containing at least two functional groups,(b) a linear or branched polyfunctional oligomer or polymer, and(c) a compound containing cross-linking and ionizable groups.The novel membranes show good mechanical, temperature and pH-stabilities and are suitable, for example, for separating monovalent ions of low ionic weight from polyvalent ions of low or high ionic weight or for separating ionic compounds from non-ionic compounds or from ionic compounds which have a different molecular weight or opposite charge.

Abstract: A multilayer membrane for performing reverse osmosis is disclosed. The membrane comprises a porous support and interfacially polymerized thereon a superposed layer of poly meta-phenylene tetrahydrofuran-2,3,4,5-tetracarboxamide in which up to 50 mole % of the tetrahydrofuran-2,3,4,5-tetracarboxamide units have been replaced with isophthalamide or terephthalamide units. The preferred material for forming the support is a polysulfone.

Abstract: A flat permeable polyolefin membrane 10 to 500 .mu.m in thickness, which has in one surface thereof a compact layer formed of intimately bound fine polyolefin particles and possessed of fine pores and in the interior and the other surface thereof a layer formed of an aggregate of fine discrete polyolefin particles of an average diameter in the range of 0.01 to 5 .mu.m so adjoined as to form fine labyrinthically continuing through pores and which, therefore, establishes communication between the opposite surfaces of said membrane.

Abstract: A process for separating a monosaccharide from an aqueous solution comprising monosaccharides and a second component comprising a polysaccharide. The mixture is contacted with a mixed matrix membrane comprising a adsorbent or molecular sieve material dispersed in an organic polymer in which the monosaccharide has a greater steady state permeability than the polysaccharide. The monosaccharide passes through the membrane, and is recovered. Particular mixed matrix membranes found to be useful in separating mono from polysaccharides are silicalite, gamma-alumina, activated carbon or a calcium exchanged Y-zeolite dispersed in cellulose acetate or polyelectrolyte complex polymers.

Abstract: Semipermeable membranes of modified styrene polymers are obtained by modifying styrene polymers containing reactive groups(A) through chemical reaction with(a) a monomeric compound containing at least two functional groups,(b) a polyfunctional oligomer of polymer, and(c) a compound containing at least one, preferably two groups capable of reaction with (b), provided that the reactive groups are amino, hydroxyl or mercapto groups,(B) through chemical reaction with components (b) and (c), provided that the reactive groups are halogen atoms, aldehyde, cyanate or thiocyanate groups, or(C) through chemical reaction with hydroxylamine and components (a), (b) and (c), provided that the reactive group is a nitrile group.The new membranes can be used in reverse osmosis and ultrafiltration processes. They show good permeability (flux) and rejection characteristics as well as good solvent, compaction and temperature resistance. Their range of molecular cut-offs lies preferably between about 200 and 2000.

Abstract: Alcoholic beverages may be passed through a reverse osmosis system to form a permeate and a retentate. The permeate will comprise mainly alcohol and water and will be removed as will a minor portion of the retentate which is recovered as product. The major portion of the retentate is recycled back to the reverse osmosis system to admix with fresh beverage and added water. The product will comprise a beverage containing a lower alcoholic content than was possessed by the fresh beverage. The semipermeable membrane which is utilized in the reverse osmosis process will possess a chloride ion rejection rate greater than about 80% at 400 pounds per square inch net pressure.

Abstract: Polycarbonate membranes are prepared for the selective separation of organic liquid mixtures, especially for the separation of ketone dewaxing solvents from dewaxed oil by preshrinking said membranes in presence of a class of solvents of solubility parameter values in the range of from 8.9 to 10 (cal/cm.sup.3).sup.0.5, and which do not dissolve the membranes.Preshrunk polycarbonate membranes, prepared by the method of the present invention, can be used for the selective separation of the various components in organic liquid mixtures such as, for the separation of dewaxing solvents from dewaxed oil, preferably the separation of ketone dewaxing solvents from dewaxed oil. The separation is based on a reverse osmosis technique whereby the solvent is permeated through the membrane under an applied pressure sufficient to overcome the osmotic pressure of the system. Applied pressures can vary from 50 up to 1,500 psi, depending on solution concentration. The separation can be carried out in the temperature range -30.

Abstract: Solutions of sulphonated polyaryletherketones in a solvent mixture of at least three liquids or low melting solids which are non-solvents or poor solvents for the polymer, can be used to produce asymmetric semi-permeable membranes. The polymer may be a polymer of(Ph.sup.1 --O--Ph.sup.2 --O--Ph.sup.1 --CO)and optionally(Ph.sup.1 --O--Ph.sup.1 --CO)and(Ph.sup.1 --O--Ph.sup.1 --O--Ph.sup.1 --CO)wherein Ph.sup.1 and Ph.sup.2 are respectively unsulphonated and sulphonated phenylene residues. The components of the solvent mixture have specified solubility parameters. A suitable solvent mixture is one formed from water, 1,4-dioxane and acetonitrile.

Abstract: A method is disclosed for the selective removal of metal ions from plating solutions comprising contacting the plating solutions with liquid organic complexing agents such as oximes or phosphoric acid esters or microporous material, preferably anisotropic, the microporous material being impregnated with such substances. The microporous material may be in various forms, including beads, fibers, sheets and gels. Copper, zinc and iron contaminants are effectively removed from nickel-plating solutions.

Abstract: Semipermeable membranes of modified polysulfones are provided which comprises repeating units of the formula--M.sub.1 --R.sub.1 --M.sub.2 --R.sub.2 --SO.sub.2 --R.sub.3 --(1)wherein M.sub.1 and M.sub.2 are independently a valence bond, --O-- or --NH--, R.sub.1 is a valence bond or a group of the formula ##STR1## with the proviso that if R.sub.1 is a valence bond, only one of M.sub.1 and M.sub.2 can be --O--, R.sub.2 and R.sub.3 are independently a group of the formula ##STR2## the aryl radicals R.sub.1, R.sub.2 and R.sub.3 are optionally further substituted, R.sub.4 is a valence bond, --O--, alkylene of 1 to 4 carbon atoms optionally substituted or interrupted by cycloalkyl(ene) or aryl(ene) of at most 7 carbon atoms, or alkylidene of 2 to 4 carbon atoms, R.sub.5 to R.sub.10 are independently hydrogen, or --R.sub.11 NH.sub.2, ##STR3## or --R.sub.

Abstract: Semipermeable membranes of modified polysulfones are provided which comprises repeating units of the formula--M.sub.1 --R.sub.1 --M.sub.2 --R.sub.2 --SO.sub.2 --R.sub.3 --(1)wherein M.sub.1 and M.sub.2 are independently a valence bond, --O-- or --NH--, R.sub.1 is a valence bond or a group of the formula ##STR1## with the proviso that if R.sub.1 is a valence bond, only one of M.sub.1 and M.sub.2 can be --O--, R.sub.2 and R.sub.3 are independently a group of the formula ##STR2## the aryl radicals R.sub.1, R.sub.2 and R.sub.3 are optionally further substituted, R.sub.4 is a valence bond, --O--, alkylene of 1 to 4 carbon atoms optionally substituted or interrupted by cycloalkyl(ene) or aryl(ene) of at most 7 carbon atoms, or alkylidene of 2 to 4 carbon atoms, R.sub.5 to R.sub.

Abstract: A system is disclosed for the purification of a caustic solution to remove impurities therefrom comprises: bringing the caustic solution into contact under pressure with the outside of a plurality of porous hollow fibers each having at least one open end and coated with a semipermeable membrane and collecting purified solution from the open ends of the hollow fibers. In a preferred embodiment, the filtering medium comprises porous hollow polysulfone fibers coated with a semipermeable sulfonated polysulfone membrane.

Abstract: A process for producing aluminum hydroxide product having an improved level of whiteness is disclosed. In the process, a caustic solution having dissolved aluminum hydroxide is subjected to purification to remove color producing humate material. Purification includes passing the caustic solution through a semi-permeable membrane. The solution purified of humate material is treated to precipitate aluminum hydroxide therefrom.

Abstract: Aliphatic thermoplastic polyamide porous membranes are reacted with an acid halide of basicity above one to provide acid radicals within the membrane. The acid halide may be derived from an aromatic carboxylic acid or an aromatic derivative of a chlorosilane. The substituted aliphatic polyamide porous membrane lend themselves to the preparation of chemical derivatives of the membrane which are not readily available by aqueous synthesis and to increased density of derivatives which otherwise may be prepared by water.

Abstract: A composite hollow fiber type separation membrane which has three layers comprising a selective separation layer, an ultra-microporous layer and a porous layer, said selective separation layer, said ultra-microporous layer, said porous layer being arranged in said order commencing from the inner surface of said hollow fiber membrane;wherein said selective separation layer is formed on said ultra-microporous layer without penetrating into said ultra-microporous layer and has a non-porous, dense structure, the average thickness of said layer being 0.01-2.mu., and the coefficient of variation in thickness thereof being less than or equal to 25%;wherein said ultra-microporous layer has a surface in which the presence of pores cannot be confirmed by 24,000 .times. scanning electron microscopy, but which has a fluid permeability at least 10 times that of said selective separation layer, the thickness of said layer being less than or equal to 0.08.mu.

Abstract: Semipermeable membranes useful for separating mixtures of ethanol and water into enriched fractions of each are prepared by cross-linking 50-90 weight percent of at least one polymer containing pendent, adjacent carboxy groups with 10-50 weight percent of at least one diamine. Membranes prepared from copolymers of maleic anhydride and styrene cross-linked with a polyoxyalkylene diamine are exemplary. These membranes are also useful in gas separation processes, such as separating oxygen from nitrogen.

Abstract: A polymeric porous membrane having a matrix made from an aliphatic thermoplastic polyamide or from an aliphatic thermoplastic polyamide/polyimide copolymer which has both relatively non-crystalline and relatively crystalline portions. The pores in the membrane are defined by spaces between the relatively crystalline portions and at least some of the relatively crystalline portions are linked together by the reaction of a bis-aldehyde with the membrane matrix.

Abstract: A composite reverse osmosis membrane which can be used to separate a solvent, generally water, from solutes dissolved therein, can comprise a flexible microporous support with a thin film membrane comprising the condensation polymerization product of a polyfunctional crosslinking compound and a polymerized amine-epihalohydrin adduct.

Abstract: The present invention relates to the membrane treatment method for semipermeable membranes, that is, a method wherein it is characterized that not only remarkable improving effect of selective separation performance of semipermeable membranes is obtained but also durability of said improving effect for selective separation performance is improved by means of extremely simple and easy procedures such as said semipermeable membranes are successively brought into contact with very dilute of aqueous solutions including effective substances which are individually water-soluble in due order and for a short time, where said effective water-soluble substances form water-insoluble or very little water-soluble materials thereof fixed on the surface of said semipermeable membranes.

Abstract: Composite reverse osmosis membranes are disclosed wherein a microporous support layer has superposed thereon an interfacially polymerized aromatic copolyamide. The aromatic copolyamide is derived from meta-phenylene diamine and, based on polymerized acid chloride present, 10 to 80% by weight repeating units derived from trimesoyl chloride, from 90 to 15% by weight repeating units derived from cyclohexane-1,3,5-tricarbonyl chloride and up to 40% by weight, repeating units derived from isophthaloyl chloride, terephthaloyl chloride or mixtures thereof. The membranes exhibit improved flux over similar membranes based on trimesoyl chloride while retaining similar salt rejection ability. The membranes containing the diacids exhibit improved flux over similar membranes based on the two triacid chlorides while retaining similar salt rejection ability.

Abstract: Low alcohol content beverages may be obtained by passing a high alcohol content beverage through a reverse osmosis system to form a permeate and a retentate. The permeate comprising mainly alcohol and water is removed. A minor portion of the retentate is recovered as product while a major portion of the retentate is recycled back to the reverse osmosis system to admix with fresh beverage and added water.

Abstract: Aliphatic thermoplastic polyamide porous membranes are reacted with an acid halide of basicity above one to provide acid radicals within the membrane. The acid halide may be derived from an aromatic carboxylic acid or an aromatic derivative of a chlorosilane. The substituted aliphatic polyamide porous membrane lend themselves to the preparation of chemical derivatives of the membrane which are not readily available by aqueous synthesis and to increased density of derivatives which otherwise may be prepared in water.

Abstract: Plasmapheresis membranes of hydrophilic polycarbonates are disclosed, comprising polycondensates of bisphenol A and a polyalkylene oxide. These membranes which have a regular pore structure with smoothly rounded pores with openings without sharp edges, have an average pore diameter of about 0.01 to 0.8.mu., a porosity preferably above 65%, and a thickness of between about 50 and 300.mu.. Processes for preparing these membranes are also disclosed, including casting a 3 to 20 weight percent polycarbonate polymer solution onto a smooth surface, contacting the layer with a gelling medium prior to precipitation of the membrane, and subsequent precipitation of the gelled layer to form the membrane.

Abstract: The present invention is directed to a process for the preparation of a segmented, aliphatic-aromatic polyether-copolycarbonate containing structural units conforming to ##STR1## wherein --D-- is a diphenolate radical and units conforming to ##STR2## wherein --O--Polyether--O-- is an aliphatic polyether-diolate radical, by the phase boundary process in which aliphatic polyether diol and a mixture of dihydroxy compounds are reacted with a carbonic acid halide which is employed in molar excess in relation to the dihydroxy compounds and in which the aqueous phase is kept at a pH value of at least 13 and where the polycondensation reaction is carried out in a reactor by addition of an amine catalyst.The invention is further directed to the polyether polycarbonate which is obtained by the process and to the preparation of membranes from said polyether copolycarbonate.

Abstract: Provided is a membrane for liquid separation which comprises mainly poly(substituted acetylene) having a repeating unit represented by the following formula: ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group, and R.sub.2 represents an alkyl group having from 1 to 3 carbon atoms.

Abstract: Modified, polyacrylonitrile-containing membranes suitable for ultrafiltration are prepared by reacting polyacrylonitrile or copolymers of acrylonitrile and other ethylenically unsaturated monomers with, successively, hydroxylamine, at least difunctional compounds, which act as bridge members, e.g. cyanuric chloride, a polyfunctional oligomer or polymer, e.g. polyethyleneimine, and, finally, a reactive compound containing at least one ionic group, e.g. an anionic reactive azo dye. The latter compound must be able to react with the polyfunctional oligomer or polymer and is required only if the said polymer does not already itself contain ionic groups.

Abstract: The present invention relates to a process for the preparation of polyether-polycarbonates, a process for stabilizing the polyether-polycarbonates thus prepared, a process for the production of membranes from the polyether-polycarbonates prepared according to the invention, stabilized membranes obtainable by the process according to the invention and the use of the polyether-polycarbonate membranes obtainable by the process according to the invention for dialysis, ultrafiltration and reverse osmosis.

Abstract: A process is disclosed for producing a composite reverse osmosis membrane. The process involves forming a porous polysulfone membrane from a solution of polysulfone followed by quenching the polysulfone membrane in an aqueous solution of m-phenylenediamine followed by reacting the m-phenylenediamine on the polysulfone membrane with either trimesoyl chloride or cyclohexane-1,3,5-tricarbonyl chloride in a water immiscible solution thereof.

Abstract: A differential pore-collapsed separation membrane particularly useful as a gas-separation membrane and a method of preparing such differential pore-collapsed membrane, which method comprises treating an asymmetric membrane, while under one-sided constraint, with a treating solution comprising a volatile nonsolvent and a swelling agent and/or a solvent, and drying the treated membrane, to provide for the controlled, differential pore collapse of the small pores of the top skin of the membrane to a smaller pore-size distribution in the membrane generally less than about 10 Angstroms.

Abstract: A process is disclosed for producing a composite reverse osmosis membrane. The process involves forming a porous polysulfone membrane from a solution of polysulfone followed by quenching the polysulfone membrane in an aqueous solution of m-phenylenediamine followed by reacting the m-phenylenediamine on the polysulfone membrane with either trimesoyl chloride or cyclohexane-1,3,5-tricarbonyl chloride in a water immiscible solution thereof.

Abstract: The preparation of syrups which contain a high glucose or maltose content may be effected in a two-step process. In the first step, a feedstock such as starch which has been pretreated with alpha-amylase to adjust the dextrose equivalent is contacted with an enzyme such as amyloglucosidase or beta-amylase immobilized on a solid support. The contact time is adjusted by correlating the residence time and the liquid hourly space velocity so as to provide a conversion percentage of starch in the range of from about 50% to 85%, thus avoiding the formation of undesired conversion products. The partially hydrolyzed reaction mixture from the enzyme treatment is then passed through an ultrafiltration membrane whereby the permeate comprising the high glucose or maltose content is recovered, while the retentate is recycled for admixture with the partially hydrolyzed reaction mixture or for further treatment with the immobilized enzyme.

Abstract: A novel composition of matter comprising a polyacrylic acid/chitosan complex. This complex is particularly useful as a membrane or filter.

Abstract: In a process for the preparation of concentrated aqueous formulations of synthetic anionic dispersants, dilute reaction solutions of said dispersants are subjected to reverse osmosis using membranes which contain ionic groups and have a pore diameter of 1 to 500 .ANG.. The dispersant formulations have a high concentration of active ingredient. They are suitable for the preparation of pigment and dye compositions and impart excellent stability to them, e.g. at elevated temperature and against mechanical influences.

Abstract: Method of making and using products for analysis of specific ligands in solution. More specifically, a method of analyzing a sample for a ligand by incubating the sample with a ligand selective binder and with a predetermined amount of ligand, the binder and/or the predetermined amount of ligand being borne by particles of predetermined size, filtering the solution and analyzing the particles which pass through the filter and/or those particles that do not pass through the filter.

Abstract: Good salt rejection, flux characteristics and resistance to degradation are obtained with semi-permeable reverse osmosis membranes made by coating a microporous substrate with a copolymer of a hydroxy containing methacrylic ester and methacrylic acid, and cross-linking the copolymer subsequent to deposition on the substrate.

Abstract: A process for the removal of urea from an aqueous solution containing same, which comprises subjecting the solution to reverse osmosis through a polymeric membrane prepared from a polymer of the formula--(--A--X--).sub.nwhereinA designates an aromatic moiety andX designates a bivalent linking group, the aromatic moiety A being chosen from the group consisting of phenyl, biphenyl, naphthyl, and mixtures of such moieties; and such moieties connected by means of linkages selected from --O--, --SO.sub.2 --, --SO--, --NH--, --CH.sub.

Abstract: Semipermeable composite membranes consisting of a microporous substrate and a semipermeable layer built of polymer material containing urazole structures.

Abstract: A method for the selective separation of at least one water-soluble useful material from an aqueous solution by reverse osmosis is provided. The method comprises contacting the aqueous solution under pressure maintained above the osmotic pressure of the aqueous solution with a semipermeable composite membrane. The semipermeable composite membrane comprises a microporous substrate and a barrier layer having about 0.01 to about 0.1 micron thickness and composed of a cross-linked polymeric material having isocyanurate structures of Formula (I) formed on the microporous substrate: ##STR1## wherein each of R.sub.1, R.sub.2 and R.sub.3 is selected from the group consisting of hydrogen, a glycidyl group, and an alkyl radical containing from 2 to 5 carbon atoms, an alkyl radical carrying a functional hydroxyl group and an alkyl radical carrying a functional glycidyl group, with the proviso that at least two of R.sub.1, R.sub.2 and R.sub.

Abstract: A semipermeable composite membrane comprising a thin semipermeable film of a polymeric material deposited on one side of a microporous substrate, the 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 herein, and having at least 0.5 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: A membrane for reverse osmosis comprising a porous base and a thin high polymer film attached to the porous base. The high polymer film includes at least one layer of radical polymer of nitrogen contained monomer and alkyl metal and at least one layer of polymer of nitrogen contained monomer which are alternately laminated on the porous base. The membrane is manufactured by combining the step of introducing nitrogen containing monomer, alkyl metal and the inert carrier gas into a plasma created by glow discharge to cause a radical polymerization reaction between nitrogen containing monomer and alkyl metal on the porous base disposed within the plasma, and the step of introducing in the plasma a nitrogen containing monomer and an inert carrier gas to cause polymerization of nitrogen containing monomer on the porous base.