Abstract: A process is provided for fabricating composite membranes by coating a porous substrate with a solution of selective polymer. A reserve of non-solvent medium is incorporated in the substrate pore network which allows the substrate to be successfully coated with a polymer solution formulated in a solvent medium which is also a solvent for the substrate material.

Abstract: Bundles of hollow filament membranes suitable for use in fluid separation, such as in the separation of air into gases more concentrated in oxygen and nitrogen are made in a cylindrical form and annular cross-section with multiple filaments of each layer lying in generally parallel helical paths at a common angle to the axis of symmetry of the bundle. Continuous lengths of filaments are laid down on the core while same is rotated first in a "forward" sense and the filament lay-down point is traversed from a first end of the core to the second, and then in a "reverse" sense while the filament lay-down point is traversed from the second end to the first. Reversing of the direction of core rotation and filament end-to-end traversal is repeated with said reversing controlled in such a manner that the path of the filament returning from either end to the other is displaced incrementally from that of the filament portion laid down in the immediately preceding traversal.

Abstract: A hollow fiber separation module is provided having a single, elongated pressurizable shell and containing multiple separation stages by multiple sections of hollow fiber bundles contained within the shell, with the ends of each bundle section potted within a single tubesheet at each end of the elongated shell. The fibers within each section are aligned so that the permeate within the fiber bores passes along paths traveling generally from one tubesheet to the other and one or more impermeable barriers are provided within the shell to isolate each section and control the passage of feed gas along the shell side of each fiber bundle section in a flow path countercurrent to the passage of permeate in the bores of the fibers.

Abstract: A hollow fiber separation module is provided having a single, elongated pressurizable shell and containing multiple separation stages by multiple sections of hollow fiber bundles contained within the shell, with the ends of each bundle section potted within a single tubesheet at each end of the elongated shell. The fibers within each section are aligned so that the permeate within the fiber bores passes along paths traveling generally from one tubesheet to the other and one or more impermeable barriers are provided within the shell to isolate each section and control the passage of feed gas along the shell side of each fiber bundle section in a flow path countercurrent to the passage of permeate in the bores of the fibers.

Abstract: The present invention provides a surface modified polymeric gas separation membrane having improved selectivity, particularly for oxygen/nitrogen gas mixtures, prepared by forming a membrane of a polymer having the structural formula ##STR1## wherein R and R" can be the same or different linear, branched or cyclic alkyl group having one to twelve carbon atoms, or R can be H, with the proviso that both R and R" cannot be methyl, and n is at least 100, and treating the surface of the membrane with a fluoro-oxidizing agent at conditions sufficient to fluoro-oxidize the membrane surface.

Abstract: Asymmetric polyacetylene polymer membranes having both improved selectivity and improved flux are provided by a process which comprises forming a solution containing from about 1 to about 5% by weight of a polyacetylene polymer in any suitable solvent therefor, forming the solution into a thin film and quenching the film in an aqueous bath in the presence of from about 0.002 to about 0.4% by weight of the quench bath of surfactant with an HLB value of 11 to 15. Additionally, the polyacetylene polymer solution contains a swelling agent at about 1% to about 10% by weight of polyacetylene polymer solution.

Abstract: The present invention is a process for applying a semi-permeable coating on a hollow fiber substrate. The hollow fiber substrate is continuously passed through a polymeric coating solution and withdrawn from the solution through a coating die to form a uniform polymeric solution coating on the outer surface of the hollow fiber. The coated hollow fiber is dried by passing it through a convective flow tunnel in which the rate of drying is controlled both by a pre-determined temperature profile in the tunnel and by a controlled air flow rate through the tunnel. The resultant material is a semi-permeable, coated composite hollow fiber membrane which can be used in gas and/or liquid separations.

Abstract: The present invention is a modified polymeric membrane having improved selectivity for separating gas mixtures. The membrane comprises a silyl substituted polyacetylene polymer to which has been added 5 to 50 wt. % of an additive which is miscible with the polymer, has a boiling point >300.degree. C. at atmospheric pressure, is soluble in a common solvent for the polymer and increases the selectivity ratio of O.sub.2 /N.sub.2 by at least 15% over the polymer without the additive.

Abstract: The present invention is a process for enhancing the permselectivity of a polymeric membrane containing substituted acetylene monomer units without adversely affecting the mechanical properties of the membrane. The process comprises irradiating the surface of the membrane with ultraviolet light while maintaining it in an environment comprising a fluid which is capable of removing surface heat from the polymer film surface without significantly absorbing or depleting the intensity of the ultraviolet rays in the range of 230-280 nm.

Abstract: The present invention is a process for applying a highly permeable coating on a hollow fiber substrate. The hollow fiber substrate is continuously passed through a polymeric coating solution and withdrawn from the solution through a coating die to form a uniform polymeric solution coating on the outer surface of the hollow fiber. A portion of the solvent from the coating is allowed to evaporate thereby forming a thin, dense surface layer after which the remaining solvent from the coating layer is leached out. The resultant material is a highly permeable, coated composite hollow fiber membrane which can be used in gas and/or liquid separations.