Abstract: Improved anisotropic fluid separation membranes are prepared from blends of polymers with surface energy differences. The membranes are formulated by processes wherein low surface energy polymer with desirable fluid separation and permeation characteristics is preferentially concentrated in the surface discriminating layer of the membrane.

Abstract: The invention involves annular hollow fiber membrane bundle comprising a plurality of helically wound layers of semi-permeable hollow fibers helically wound thereon and at least one reinforcement filament which has been helically wound concurrently with said hollow fibers into the hollow fiber membrane bundle. A preferred embodiment provides that the reinforcement filament is uniformly distributed throughout the diameter of the bundle and/or across the axial length of the bundle. Though, other embodiments provide a non-uniform distribution throughout the diameter of the bundle and/or across the axial length of the bundle.

Abstract: Improved anisotropic fluid separation membranes are prepared from blends of polymers with surface energy differences. The membranes are formulated by processes wherein low surface energy polymer with desirable fluid separation and permeation characteristics is preferentially concentrated in the surface discriminating layer of the membrane.

Abstract: A process for the preparation of anisotropic hollow fibers useful as permselective separation membranes and for producing composite membranes thereof, involves extruding a spinning dope through a spinneret that extends into a coagulation chamber maintained at subatmospheric pressure, conveying the nascent hollow fiber through a column that extends into the reduced pressure chamber, and contains at least two different abutting liquids arranged in sequence. An apparatus for conducting the process includes the vacuum chamber, the spinneret and the column that extends into the vacuum chamber and is equipped with entrance and exit ports for introduction and removal of at least two abutting liquid coagulation media.

Abstract: The invention comprises an annular hollow fiber membrane module comprising a plurality of helically wound layers of semi-permeable hollow fibers, wherein the fiber wind angle varies across the axial length of the module in one or more layers. In a preferred embodiment, the module has at least one tubesheet region and an active region, and the wind angle in the tubesheet region of the module differs from the wind angle in the active region of the module. A method of making the module, and a separation module which includes the module described above is also disclosed.

Abstract: Improved anisotropic fluid separation membranes are prepared from blends of polymers with surface energy differences. The membranes are formulated by processes wherein low surface energy polymer with desirable fluid separation and permeation characteristics is preferentially concentrated in the surface discriminating layer of the membrane.

Abstract: Novel polyimide gas separation membranes and the process of using such membranes to separate gases are disclosed. The polyimides are formed from rigid aromatic dianhydrides and aromatic diamines that contain sulfonic acid, salified sulfonic acid, or sulfonic ester groups. Methods of preparing improved composite gas separation membranes from the sulfonated polyimides of this invention are disclosed.

Abstract: The invention involves annular hollow fiber membrane bundle comprising a plurality of helically wound layers of semi-permeable hollow fibers helically wound thereon and at least one reinforcement filament which has been helically wound concurrently with said hollow fibers into the hollow fiber membrane bundle. A preferred embodiment provides that the reinforcement filament is uniformly distributed throughout the diameter of the bundle and/or across the axial length of the bundle. Though, other embodiments provide a non-uniform distribution throughout the diameter of the bundle and/or across the axial length of the bundle.

Abstract: Gas separation membranes are prepared from sulfonated polyimides exhibiting desirable gas separation characteristics, combined with good film-forming properties and desirable solubility characteristics.

Abstract: Improved fluid separation membranes are prepared from the blends of polyetherimide with phenylindane containing polyimides, wherein the amount of phenylindane containing polyimide in the blend is low. The present invention provides for highly anisotropic membranes particularly useful for gas separation applications and for preparation of composite membranes thereof.

Abstract: The invention relates to a hollow fiber membrane fluid separation assembly having an integral purge control valve or a purge fluid reflux system, which provides a sweep fluid port internal to the assembly. This assembly is useful for, among other things, separating water vapor from a gas stream.

Abstract: The present invention relates to fluid separation composite membranes prepared from sulfonated aromatic polymers in lithium salt form with sulfonic acid groups attached to aromatic rings that are incorporated into the main polymeric backbone.

Abstract: Multilayer composite membranes are produced in a one-step coating process that provides an interior gas separation layer and an external defect sealing layer.

Abstract: The present invention relates to composite membranes and membranes which are formed from modified poly(phenylene oxide) polymers having improved film forming properties and separation characteristics. The present invention further relates to poly(phenylene oxide) polymer and modified poly(phenylene oxide) polymer, having improved membrane forming characteristics and processes for producing the same.

Abstract: Operative fluids containing lower glycol are contacted with semi-permeable membranes under reverse osmosis conditions to permeate lower glycol to provide a reclaimed lower glycol product. Exemplary operative fluids include antifreeze solutions, heat transfer fluids, deicers, quenchants, hydraulic fluids, lubricants, solvents and absorbents.

Abstract: A process for producing highly asymmetric hollow fibers useful as permselective gas separation membranes and for producing composite membranes thereof by extruding the spinning dope through a tube-in-orifice spinneret into a gas-filled chamber maintained at reduced pressure and then conveying the extruded hollow fiber through a liquid bath to solidify the extrudate.

Abstract: An annular double ended hollow fiber bundle, a fluid separation apparatus comprising the annular double ended hollow fiber bundle having bores open at both ends of the hollow fibers embedded in the two tubesheets enclosed in a shell having multiple ports, a fluid entrance port, a non-permeate exit port and at least one permeate exit port, wherein said double ended hollow fiber bundle is encased in an essentially impermeable film barrier except for entrance regions situated in selected areas between the tubesheets and to processes for separating fluids mixtures.

Abstract: This invention relates to methods for producing composite gas separation membranes by treating the gas separation layer of the composite membranes with a treating agent that ionically bonds to the gas separation membrane layer of the treated composite membrane. The invention also relates to the membranes produced and to gas separation processes utilizing the improved membranes.

Abstract: Operative fluids containing lower glycol are contacted with semi-permeable membranes under reverse osmosis conditions to permeate lower glycol to provide a reclaimed lower glycol product. Exemplary operative fluids include antifreeze solutions, heat transfer fluids, deicers, quenchants, hydraulic fluids, lubricants, solvents and absorbents.

Abstract: Semipermeable membranes comprised of certain sulfonated substituted polysulfone polymers containing the polymer repeat unit (A) or (B) as herein defined. The invention also pertains to processes for using said membranes for the selective permeation of at least one gaseous component from a mixture of gases containing said gaseous component in admixture with other gaseous components.