Abstract: Porous poly(aryl ether ketone) (PAEK) articles are prepared from PAEK/polyimide blends by selective chemical decomposition and subsequent removal of the polyimide phase. Porous PAEK articles exhibit highly interconnected pore structure and a narrow pore size distribution. The porous PAEK articles of the present invention can be utilized as a porous media for a broad range of applications, including membranes for fluid separations, such as microfiltration, ultrafiltration, nanofiltration, and as a sorption media.

Abstract: The preparation and use of novel porous poly(aryl ether) articles is disclosed. The porous articles are prepared from blends of poly(aryl ether) polymers with polyimides by selectively decomposing the polyimide phase. The preferred reagents used to decompose the polyimide phase include monoethanolamine and tetramethylammonium hydroxide. The porous articles can be configured as a single layer or as a multilayer article. The porous articles of the present invention are unique that at least one of the layers exhibits a narrow pore size distribution. The articles of the present invention can be used as a porous media for a broad range of applications, including porous membranes for fluid separations, such as microfiltration, ultrafiltration, and gas separation, as a battery separators, and as a sorption media.

Abstract: The present invention deals with a process for treating a polyimide comprising exposing said polyimide to a compound selected from the group consisting of dendrimers, hyperbranched polymers and mixtures thereof. The polyimide may be in the form of a membrane and the membrane, after treatment according to the process of the invention, may be suitable for use in a membrane-based separation technique, for example gas separation, filtration, microfiltration, ultrafiltration, reverse osmosis or pervaporation. The membrane may for example be suitable for separation of gas and hydrocarbon mixtures including mixtures of H2/N2, H2/CO2, He/N2, CO2/CH4, and C2-C4 hydrocarbon mixtures.

Abstract: Soluble polyamic acid salt (PAAS) precursors comprised of tertiary and quaternary amines, ammonium cations, sulfonium cations, or phosphonium cations, are prepared and fabricated into membranes that are subsequently imidized and converted into rigid-rod polyimide articles, such as membranes with desirable gas separation properties. A method of enhancing solubility of PAAS polymers in alcohols is also disclosed.

Abstract: The invention relates to preparation and uses of novel polymeric materials, polyimide amic acid salts (PIAAS). The use of these materials for the fabrication of fluid separation membranes is further disclosed.

Abstract: A process is provided for chemically modifying a dual-layer hollow fibre, wherein the fibre comprises a first layer consisting essentially of a polyimide and a second layer consisting essentially of a polymer which is substantially unaffected by the chemical modification process. The process comprises contacting the polyimide layer with a polyamine. In addition, a process is provided for chemically modifying a polyimide membrane in general, using a process which comprises contacting the membrane with an alcoholic solution of an aliphatic-aromatic polyamine.

Abstract: This invention relates to a hollow fiber membrane module to be used in industrial fields such as the semiconductor industry, food processing industry, pharmaceutical industry, and medical industry, and to a method for the production thereof. Permselective hollow fiber membranes having rigidity are cheese-wound in a plurality of layers, thereby forming a hollow fiber membrane bundle. One terminal part of this hollow fiber membrane bundle together with a case is adhered and solidified with a thermally molten mass of thermoplastic resin, thereby forming a solidified part. This solidified part is cut to form a sealed part serving to open terminal parts of the hollow fiber membranes.

Abstract: The invention relates to a method of producing nanostructures in membranes, in which method a membrane consisting of a polymer material is irradiated with charged particles, especially ions, to produce particle tracks. The particle tracks in the membrane are etched using an etching liquid and the etching operation is stopped using a stop liquid, in such a manner that asymmetrical structures are formed. Polyimide is used as the membrane material.

Abstract: Solvent-resistant polybenzimidazole membranes, methods of making them and crosslinking them and composite membranes and hollow fiber membrane modules from them are disclosed.

Abstract: A polymeric composite may be used for forming fluid separation membranes. The fluid separation membranes may go through a separation selectivity maximum as a function of operating conditions (e.g., temperature and/or pressure). The membranes may be formed from polyamide or poly (pyrrolone-imide). Polyamides may be formed by the condensation of a tetraamine, a tetraacid, and a diamine. Poly (pyrrolone-imides) may be formed by the condensation of a polyamide.

Abstract: A polyimide porous film obtained by drying and imidizing a polyimide precursor porous film which is substantially homogeneous on both sides, the polyimide porous film having pores on both sides wherein the pores all satisfy the conditions: 1) the difference in the mean pore size of both sides is less than 200% based on the smaller average value of the mean pore size, 2) the coefficient of variation for the pore size on each side is smaller than 70%, 3) the coefficient of variation for the pore centroid distance on each side is smaller than 50%, and 4) the mean pore size on each side is 0.05-5 &mgr;m.

Abstract: A pore plugging material, for pH dependent membrane diffusion, in which cyclic olefins having phosphazene-functional moieties provide predictable erosion properties when used to plug pores in separation barriers and other porous membranes. Specific properties of the polymers are dependent on several factors, including molecular weight and identity of side groups attached to the phosphazene moiety. However, as a class, phosphazene-functional cyclic olefins provide both predictable erodibility and uniformly benign hydrolysis products and are, therefore, uniquely suitable as pore plugging polymers for separation barriers and membranes of all kinds. The invention, therefore, embraces the provision of a pH-sensitive erodible pore plugging material for pores in separation barriers and membranes of all kinds.

Abstract: The invention concerns a filter material characterized in that it is impregnated with an amphiphilic substance or with a hydrophilic and a hydrophobic substance to control the water wettability and water absorption.

Abstract: An asymmetric support membrane can be prepared by using a phase separation method. The method includes immersing a polymer solvent solution into water. The polymer solution is made by dissolving 15 to 35% by weight of the polymer into a solvent that lets the polymer solution become a gel at a temperature of 0 to 50° C. The solution is then allowed to gel and brought into a final membrane form in water for phase separation and formation of the asymmetric support membrane. The polymer may be poly(vinyl chloride), polyethersulfone, polyetherimide and polyamic(methylester). The solvent is &ggr;-butyrolactone alone as a major solvent or is a mixed solvent with N-methyl-2-pyrrolidone as a cosolvent. The asymmetric support membrane is a porous support membrane of a sponge form having open pores that are connected to one another with a narrow pore size distribution. Thus, the asymmetric support membrane has an improved permeance and mechanical strength.

Abstract: A method of manufacturing a three dimensional structure. In one embodiment, such structures comprise porous structures suitable for implantation in a host. Such a structure preferably exhibits geometric properties that tend to promote vascularization in the area of the structure when implanted into a host. The method includes selectively applying and exposing layers of biocompatible photoimageable material to create layers forming a cross-linked latticework structure having the desired geometric properties. Each layer is formed on top of a prior layer, preferably before any layer is developed. In one form, the structure is manufactured in connection with an implant device and promotes vascularization that supports bioacceptance/biocompatibility of the implant device.

Abstract: The invention relates to sulphonated polyimides, notably of formula (I) The invention also relates to an ion exchange membrane that includes such a polyimide and a fuel cell that includes such a membrane. The membranes of the invention have excellent durability and low cost and the fuel cells can be used, in particular, in electric vehicles.

Abstract: A gas separation membrane is formed from a copolyimide produced by copolymerization of monomers which include o-tolidine sulfone, at least one other hydrophilic diamine and 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride. One or more additional aromatic dianhydrides can optionally be included. The novel membrane exhibits an excellent combination of high selectivity of gases to be separated from a gas mixture, high permeability and strong solvent resistance to hydrocarbon chemicals. The membrane is therefore useful in separating gases from gas mixtures in which vapor or liquid hydrocarbon contaminants are present, for example in the separation of carbon dioxide from methane and/or nitrogen in the purification of natural gas.

Abstract: A method and apparatus for filtering suspensions of medical and biological fluids, one aspect of which is separating a suspension comprising at least two types of particles which are differently sized or shaped and in which the first type of particle may be deformable at a relatively lower force and/or faster rate than the second type of particle. A filter member is provided having substantially precisely dimensioned pore sizes, with the pores being dimensioned to allow passage of the first type of suspended particle without distortion or only minimal distortion and passage of the second type of particle only with substantial distortion.

Abstract: A porous material is disclosed, made of a semi IPN type polymer alloy of a crosslinked polymer (A) obtained by the crosslinking polymerization of a crosslinking-polymerizable vinyl monomer and/or oligomer (a) with a non-crosslinked polymer (D) which is soluble in a solvent (B) capable of dissolving said monomer and/or oligomer (a) therein and subjecting said crosslinked polymer (A) to gelation but is insoluble in a coagulating solution (C) which is compatible with said solvent (B) but doesn't subject said crosslinked polymer (D) to gelation. A porous material excellent in mechanical strength as well as in heat resistance can be prepared. Various functional groups can be introduced into the surface of the porous material. Further, the pore diameter can be easily controlled.

Abstract: Improved asymmetric hyperfiltration membranes and their method of preparation and use are disclosed. The membranes are fashioned from polyimides and conditioned with a lubricating oil. Permselective separation of aromatic hydrocarbons from non-aromatic hydrocarbons in a feed stream may be accomplished using the membranes under hyperfiltration conditions.