Abstract: A dope for forming membranes and the resulting asymmetric gas separation membranes are disclosed, the membranes having graded density skins which exhibit improved permeability characteristics and increased failure pressure strength. The membranes are produced from a process utilizing membrane forming dopes of complexing solvent systems formulated from two non-solvents and one or more solvents. The non-solvents are chosen one each, from non-solvents grouped according to non-solvent strength, i.e., one strong non-solvent and one weak non-solvent which are combined with one or more solvents in an acid:base complex solvent system for dissolving high weight percent total solids of membrane forming polymers. The process for forming the membranes is also disclosed.

Abstract: A dope for forming membranes and the resulting asymmetric gas separation membranes are disclosed, the membranes having graded density skins which exhibit improved permeability characteristics and increased failure pressure strength. The membranes are produced from a process utilizing membrane forming dopes of complexing solvent systems formulated from two non-solvents and one or more solvents. The non-solvents are chosen one each, from non-solvents grouped according to non-solvent strength, i.e., one strong non-solvent and one weak non-solvent which are combined with one or more solvents in an acid:base complex solvent system for dissolving high weight percent total solids of membrane forming polymers. The process for forming the membranes is also disclosed.

Abstract: Asymmetric gas separation membranes having graded density skins and macrovoid-free morphology comprised of glassy, hydrophobic polymers are disclosed which are effective for separation gases with significante increases in permeation while maintaining equal or greater separation electivity. The membranes have increased free volume and the graded density skin exhibits a density gradient which becomes more dense with increasing proximity to the surface, the membrane effectively decouples the interdependency between permeability and separation selectivity.

Abstract: A process for forming high free volume, asymmetric gas separation membranes having graded density skins and macrovoid-free morphology from a solvent system comprising a Lewis acid, Lewis base, and a Lewis acid:base complex which dissolve hydrophobic polymers. The dopes have high total solids, high viscosity and low coagulation (g) values which enhance rapid gelation without the formation of macrovoids and which minimize densification. The dope solvent system complexes are readily disassociated by the coagulation medium and the component molecules are miscible in the medium which provides for rapid desolvation of the formed membrane thus providing a membrane having low residual solvent retention.

Abstract: Asymmetric gas separation membranes of materials having selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture, exhibit significantly improved permeation selectivities for the at least one gas when the asymmetric membrane is contacted on one or both surfaces with an effective amount of a Bronsted-Lowry base. The improved asymmetric gas separation membranes, process for producing the improved membrane, and processes utilizing such membranes for selectively separating at least one gas from a gaseous mixture by permeation are disclosed.

Abstract: A coated membrane for gas separations wherein the membrane is made up of an amine cross-linked poly(phenylene oxide) substrate membrane having about 1 to about 7 weight percent nitrogen and a coating on the substrate membrane. The coating is a polymer containing groups capable of reacting with amine groups at the surface of the substrate membrane to ionically or covalently bond the coating to the substrate.

Abstract: Covalently-bonded, cross-linked polymeric gas separation membranes of a polyarylene oxide precursor and a chemical cross-linking agent. Apparatus and processes utilizing such membranes for selectively separating at least one gas from a gaseous mixture by permeation.Membranes include substituted phenylene oxide polymers cross-linked with ammonia.

Abstract: Asymmetric gas separation membranes of materials having selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture, exhibit significantly improved permeation selectivities for the at least one gas when the asymmetric membrane is contacted on one or both surfaces with an effective amount of a Lewis acid. The improved asymmetric gas separation membranes, process for producing the improved membrane, and processes utilizing such membranes for selectively separating at least one gas from a gaseous mixture by permeation are disclosed.

Abstract: Asymmetric gas separation membranes of materials having selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture, exhibit significantly improved permeation selectivities for the at least one gas when the asymmetric membrane is contacted on one or both surfaces with an effective amount of a Br nsted-Lowry acid. The improved asymmetric gas separation membranes, process for producing the improved membrane, and processes utilizing such membranes for selectively separating at least one gas from a gaseous mixture by permeation are disclosed.

Abstract: Cross-linked polyphenylene oxides comprise the reaction product of alkyl halogenated phenylene oxide polymer and primary monoamines, such as methylamine, ethylamine, propylamine, butylamine and aniline. Such cross-linked polyphenylene oxide compositions are useful as membranes.

Abstract: Cross-linked polyphenylene oxide compositions comprise the reaction product of haloacylated polyphenylene oxide and a primary monoamine. The polyphenylene oxide chains are cross-linked by amino ketone bonding. Such cross-linked polymers are useful as membranes, for instance gas separation membranes.

Abstract: Cross-linked polyphenylene oxide compositions comprise the reaction product of an alkyl halogenated phenylene oxide polymer and ammonia. The cross-linkage between phenylene groups is benzyl amine linkage represented by the structural formula --CH.sub.2 NHCH.sub.2 --. The cross-linked polyphenylene oxide is useful as a membrane.

Abstract: Cross-linked polyphenylene oxide compositions comprise the reaction product of haloacylated polyphenylene oxide and ammonia. The polyphenylene oxide chains are cross-linked by amino ketone bonding. Such cross-linked polymers are useful as membranes, for instance gas separation membranes.