Abstract: A composite membrane and method for making the same, comprising a porous support and a polyamide surface. The subject membrane provides improved flux and/or rejection rates. The subject membrane is further capable of operating at lower operating pressures. The subject method includes reacting a polyfunctional amine with a polyfunctional acyl halide to form a polyamide. The method includes the step of contacting a complexing agent with the polyfunctional acyl halide prior substantial reaction between the polyfunctional acyl halide and a polyfunctional amine. The subject process is easily adapted to commercial scale manufacturing processes and is particularly suited for making nanofiltration and reverse osmosis composite membranes.

Abstract: Porous polymers having a plurality of openings or chambers that are highly convoluted, with each chamber being defined by multiple, thin, flat partitions are produced by a new gel enhanced phase separation technique. In a preferred embodiment, a second solvent is added to a polymer solution, the second solvent causing the solution to gel. The gel can then be shaped as needed. Subsequent solvent extraction leaves the porous polymeric body of defined shape. The porous polymers have utility as medical prostheses, the porosity permitting ingrowth of neighboring tissue. The present technique also enhances shape-making capability, for example, of bifurcated vascular grafts, which feature a common entrance region but two or more exit regions.

Abstract: The invention provides micro- and nano-porous materials made from crosslinked polymers crystallized from supercritical fluids. The resulting products show an open cell porous network, and can be used for a variety of applications in medical fields, textiles, separation science and others. The invention also provides methods for obtaining such products.

Abstract: A microporous film of polyethylene having an intrinsic viscosity above 5 dl/g is prepared from a homogeneous solution in an evaporable solvent. The film is cooled and evaporable solvent is evaporated at a temperature below the dissolution temperature. The film is stretched to produce the micorporous film and is passed through a calender. The microporous films with a porosity of up to about 70% by volume and a battery separator quality factor (F) of at least 2.5 are described. Battery separators formed from the microporous films are also described.

Abstract: A reverse osmosis membrane having excellent antifouling property, which is advantageous in terms of fundamental prevention of fouling generated by inorganic crystalloids, organic contaminants, and microorganisms, and a method for preparing the same. The membrane can be manufactured by hydrolyzing a titanium compound in an acidic aqueous solution to produce TiO2 particles of nano scale; dispersing the produced TiO2 particles in an acidic aqueous solution of pH 1-6 or an alkaline aqueous solution of pH 9-13 to yield a stable TiO2 dispersed solution; and immersing a reverse osmosis membrane prepared by a known method in the TiO2 dispersed solution to incorporate TiO2 into the membrane.

Abstract: A method for preparing a highly porous, high surface area degradable or partially degradable material. The method comprises the steps of mixing a degradable or partially degradable polymer with a mixed solvent comprising a first solvent and a second solvent, wherein the mixed solvent comprises a ratio higher than 1:1, first solvent to second solvent; gelling the mixture; and treating the gel under conditions whereby a substantially solvent free porous structure is created having a porosity greater than about 80%; wherein the material is mechanically strong and has a complex porous structure with nano fibrous architecture.

Abstract: A method for preparing a highly porous, high surface area non-degradable material, comprises the steps of mixing a non-degradable polymer with a solvent or mixture of solvents; gelling the mixture; and treating the gel under conditions whereby a substantially solvent free porous structure is created having a porosity greater than about 80%. The resultant material is mechanically strong and has an architecture comprising at least one of nano fibrous, micro fibrous, non fibrous, complex porous structure with nano fibrous architecture, and mixtures thereof.

Abstract: A fabrication method to rapidly fabricate different prototypes of drug delivery systems, medical devices, pharmaceutical dosage forms, tissue scaffolds or other bioaffecting agents in small batches or individual forms using a computer-guided system to vary the composition and structure in order to optimize the product and the manufacturing process. The process is immediately scalable. An Expert System can be used with the method to recommend different compositions and designs of the prototypes, devices, dosage forms, tissue scaffold or other bioaffecting agents.

Abstract: Provided is a porous film which is excellent in a tear strength and has a low heat shrinkage.

Abstract: Polytetrafluoroethylene thin film comprising a thin film of polytetrafluoroethylene having thickness of ≦20 &mgr;m; surface roughness (Ra) of ≦0.1 &mgr;m; tensile strength of ≧80 N/mm2; and light beam transmittance of ≧80% for light of 500 nm wavelength. A process for manufacture of polytetrafluoroethylene film comprising compressing porous polytetrafluoroethylene film at a temperature above the melting point of the film, followed by cooling to a temperature below the melting point of the film while continuing to apply pressure.

Abstract: High quality reverse osmosis, nanofiltration, and ultrafiltration membranes are produced by a high speed process wherein the membranes which have excellent rejection characteristics coupled with high flux capabilities. The process employs tandem coating techniques to coat a microporous substrate with a thin membrane on the order of 25 Å to 1.0 microns. The tandem coating process comprises tandem offset gravure and subsequent slot die coating applicators, or alternatively comprises tandem slot die coating applicators. For reverse osmosis and nanofiltration membranes, a wet-on-wet coating process is used to coat a porous substrate first with an aqueous solution, and then with an organic solution to produce a cross-linked, interfacially polymerized composite membrane. Single slot coating applicators are utilized to produce ultrafiltration membranes.

Abstract: A mesoporous polymeric membrane for use as an ionically-conductive inter-electrode separator in a rechargeable battery cell is prepared from a coatable composition comprising a polymeric material, a volatile fluid solvent for the polymeric material, and a second fluid miscible with and of lesser volatility than the solvent, the second fluid being a nonsolvent exhibiting no significant solvency for the polymeric material. A layer is cast from the composition to form a layer which is gelled and solidified to a self-supporting membrane by volatilizing the solvent and nonsolvent coating vehicle fluids under conditions in which the solvent volatilizes at a rate substantially faster than that of the nonsolvent.

Abstract: A hydrophobic polymer fiber having a cationically charged coating thereon, in which the coating includes a functionalized cationic polymer, such as an epichlorohydrin-functionalized polyamine or an epichlorohydrin-functionalized polyamido-amine, which has been crosslinked by heat. The present invention also provides a fibrous filter which includes hydrophobic polymer fibers having the foregoing cationically charged coating thereon. The present invention further provides a method of preparing a fibrous filter.

Abstract: A method for preparing microparticles having a selected polymer molecular weight. The hold time and temperature of a solution containing a nucleophilic compound and a polymer having a starting molecular weight are controlled in order to control the molecular weight of the polymer in the finished microparticle product. In this manner a selected polymer molecular weight in the finished microparticle product can be achieved from a variety of starting material molecular weights.

Abstract: A microcapsule having a mean diameter of from about 0.1 to about 5 mm, a membrane and a matrix containing at least one active principle wherein the microcapsule is the product of the process comprising the steps of (a) forming an aqueous matrix by heating an aqueous solution comprised of a gel former, a chitosan and active principle; (b) adding the aqueous matrix to an aqueous solution of an anionic polymer selected from the group consisting of a salt of alginic acid and an anionic chitosan derivative.

Abstract: Systems and methods for processing dope for the manufacture of microporous phase inversion membrane having any one of a plurality of different pore sizes from a single master dope batch is disclosed. The systems and methods include formulating a single master batch of dope preferably maximizing the non-solvent to solvent ratio for a given weight percentage of polymer for use in a microporous phase inversion membrane casting operation to produce phase inversion membranes having one of a plurality of different predetermined pore sizes. The master dope batch is controllably formulated in a vessel such that the temperature of the dope does not exceed a predetermined maximum mixing temperature and is maintained at a relatively low temperature (lower than the mixing temperature) suitable for storage.

Abstract: When forming a separating functional layer containing crosslinked polyamide, by carrying this out in the presence of 1) carboxylic acid ester with a total of 8 or more carbons, or 2) carboxylic acid, it is possible to provide a composite semipermeable membrane which, while still maintaining a high rejection rate, is more outstanding in its water permeability than hitherto.

Abstract: A process for producing a carbon foam heat sink is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications. The foam is encased and filled with a phase change material to provide a very efficient heat sink device.

Abstract: A novel porous fibrous structure containing from 10 to 100% by weight of wet heat bonding fibers, having cellular cavities in the fibrous structure of the fibers, in which a plurality of indefinite cellular cavities are present independently or in a state of partially connected in the inside of the fibrous structure, at least a portion of the fibers constituting the fibrous structure is heat bonding by the wet heat bonding fibers, and a process for producing such porous fibrous structure.

Abstract: Process for producing integrally asymmetrical hydrophobic polyolefinic membranes with a separation layer, in particular for gas exchange, via thermally induced liquid-liquid phase separation. A solution of at least one polyolefin in a solvent system containing a compound A and a compound B is extruded to form a shaped object. Compound A is a strong solvent and compound B a weak non-solvent for the polymer. After leaving the die, the shaped object is cooled using a solid or liquid cooling medium, which does not dissolve the polymer and does not react chemically with it, until the phase separation and solidification of the high-polymer-content phase take place.

Abstract: A membrane which can be used in membrane filtration processes and which has a reduced tendency to fouling is a polysulphone or a plyether sulphone and a polyethylene oxide/polypropylene oxide substituted diamine and can be made by a phase inversion process in the presence of pore modifying agents such as an alcohol, glycerol or glycol to give a membrane which has a pore size of 0.1&mgr; to 1 micron and is hydrophilic.

Abstract: The invention is directed broadly to microporous films prepared from immiscible blends of at least two components, preferably polymers, which are produced via melt processing, a film formed therefrom, for example by extrusion and post-film-forming treatments comprising uniaxial or biaxial cold-stretching and hot-stretching. The films have a three-dimensional reticulated or interconnected network of microcracks or crazing throughout the film, extending from one surface of the film to the other, providing a stable porosity and pore size useful for a variety of filtration and other applications.

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: Sheet material especially for beverage and food containers, and methods of making. The sheet material comprises a layer of paperboard and expanded, preferably non-syntactic, foam layer applied as an unexpanded coating, preferably about 1-76 microns thick, in a liquid carrier, to the paperboard layer. The expanded foam has a remote surface preferably defined by intermingled randomly-spaced peaks and valleys. The coating is preferably sufficiently continuous to prevent a user's finger from touching the substrate, and sufficiently insulating that a person can hold a container of 100 degree C. liquid, having sidewalls made from the sheet material, without discomfort. A cover layer can overlie the foam. The substrate can include a heat seal layer, with the paperboard between the heat seal layer and the expanded foam layer; or with the foam layer between the heat seal layer and the paperboard. Preferred composition for the foam layer is PVDC or AMM.

Abstract: A beaded preform includes a plurality of adjacently positioned beads for forming a plurality of voids in an engineered material. The beaded preforms may be comprised of a filaments (single strand of beads) and mats (two-dimensional and three dimensional arrays of beads). The filaments and mats may be coated to become tows and laminates, respectively, which may then be assembled into composite materials. The preforms may be produced using novel manufacturing apparatuses and methods, and incorporated into known manufacturing processes to produce porous structures, including stress-steering structures, in any material including metals, plastics, ceramics, textiles, papers, and biological materials, for example.

Abstract: An apparatus and method for controlling the pore structure of thin polymeric sheets, such as porous membranes and thin films, during solvent casting or interfacial polymerization. The invention may be used to reduce or eliminate macrovoid pore defects from solvent-cast or interfacially polymerized polymeric membranes used in a variety of separations or controlled release tasks or to create a desired pore structure in porous thin films, such as may be used in breathable garments, surgical dressings, and screen printing. A nonuniform electric field is generated at one or more locations in proximity to a liquid film in which a desired pore structure is to be formed. Due to the difference in dielectric constant between the liquid within the pores and that in the surrounding liquid, the electric field causes an attractive or repulsive force on the evolving pores.

Abstract: The present invention relates to polymer membrane meshes having pores with an average diameter from about 10 &mgr;m to about 200 &mgr;m. The membrane meshes are cast from polymer dope mixes that are either homogeneous solutions or stable colloidal dispersions.

Abstract: A reinforcement for an expandable or foaming material is disclosed that comprises a first and a second member each having protuberances that are contacted when the first and second members are joined. The members are joined by bending a hinge that separates the members, or can be joined in multiple units to form a series. The members are maintained in a closed or joined position by at least one latch. Once joined, the first and second members define at least one opening wherein a foaming composition can be injected into the joined members. Alternatively, a preformed expandable material can be placed between the first and second members, or located on selected outer positions, e.g., within an automotive cavity to be sealed.

Abstract: A method is provided for producing porous hydrophilic materials whereby nonporous materials are subjected to ester hydrolysis to generate site-specific perforations. Processes for separating aqueous phase from organic and aqueous mixtures utilizing the invented materials also are provided.

Abstract: Selective, water-permeable membranes for reverse osmosis and nanofiltration are prepared by interfacially polymerizing on a microporous support an essentially monomeric bipiperidine reactant, and an essentially monomeric amine-reactive polyfunctional aromatic or cycloaliphatic acyl halide having on the average at least about 2 acyl halide groups per reactant molecule. The polymerization is optionally carried out in the presence of a monomeric amine salt, which can increase the flux rate of the resulting membrane.

Abstract: A polymeric material including a microporous matrix disposed in a multi-block polymer having a backbone of the general formula: [(A)n−(B)m−(X)l]p wherein: A is a first copolymerized monomer; B is a second copolymerized monomer; X is a third copolymerized monomer the same as or different from A; n and m are the same or different and are each an integer in the range of from 30 to 3000; is 0 or an integer in the range of from 30 to 3000; p is an integer in the range of from 1 to 100; wherein the microporous matrix is defined by reactive cleavage of at least a portion of a pendant moiety on B. The polymeric material is produced by a process which comprises cleavage of at least a portion of pendant moiety on B while leaving the backbone of the copolymer intact. This approach facilities production of a substantially uniform distribution of very small pores of substantially uniform dimension.

Abstract: A method and apparatus for producing microporous films. The method utilizes a casting surface and a condensing surface. The condensing surface is spaced from the casting surface to form a gap. The distance between the surfaces forming the gap is relatively small and is preferably less than 3 cm. A material, capable of forming microporous films through thermally induced phase separation processes, is cast onto the casting surface, preferably through conventional extrusion practices. The material contains at least one evaporative component that generally flashes off upon formation of the microporous material and condenses on the condensing surface.

Abstract: A baffle may conform to and be magnetically coupled to a body having a ferromagnetic component in proximity to the baffle. The baffle includes a first layer of a flexible thermally expansible baffle material which expands when subjected to an elevated temperature, and a second layer of a flexible magnetic material. The baffle may thereby be flexed to conform to an irregular or curved surface. In addition, the baffle may be preformed to provide an irregular or arcuate portion to conform to the body on which it is placed. The magnetic attachment facilitates attachment and removal without the need to provide holes in the body, and upon heating and expansion of the baffle, the baffle material expands to fill cavities and adhere to the inside wall surface of the body on which it is received.

Abstract: A method and apparatus for recycling plastic waste to produce a wood substitute material for use in manufacture of garden products. A mixture of one or more types of plastic materials is extruded in a partially plasticised condition so as to allow gases formed by the extrusion process to escape from the surface of the extrusion to create a simulated wood. Holes (9) formed in the surface of the extruded plastic material by escaping gases are elongated by passage of the extrusion through a finishing die (7) downstream of the extruder (5) to form a rough textured surface similar to sawn wood and the plastic material is set to retain the shape and configuration of the textured surface by cooling in a water bath (8) downstream of the finishing die (7).

Abstract: A hollow shrinkable fiber is manufactured by wet spinning a copolymer of acrylonitrile and a halogen-containing vinyl monomer, and then carrying out steam treatment, followed by drying treatment, and then heat treatment, thus forming a marrow-like or network-like hollow portion comprising a large number of voids in a core part of the fiber cross section. The void ratio of the fiber cross section is 10 to 50%, and the dry heat shrinkage percentage of the fiber is at least 15%. The fiber has a hollow form similar to that of natural fur, is excellent in terms of bulkiness, a lightweight feeling and warmth retention, and can be used as down hairs in pile products.

Abstract: Highly asymmetric polymeric membranes with large pores which yield bubble points in the range of 0.5 to 25 psid and superior flow characteristics. The membranes can be cast from both metastable dispersions and from homogenous casting formulations. The technique of synthesis involves exposure of the cast membrane to humid air to create large surface pores on the exposed side.

Abstract: A method for preparing a hollow fiber-type separation membrane from high density polyethylene is provided, which includes the steps of: melt-spinning a mixture of a high density polyethylene and a diluting agent to produce a phase-separated undrawn hollow fiber; detecting a tensile strength of the undrawn fiber during an alternative and repetitive winding and unwinding procedure between two bobbins, said undrawn fiber being drawn during the alternative and repetitive winding and unwinding procedure; reducing a rotation speed of one of the two bobbins when the detected tensile strength is larger than a predetermined value; and increasing a rotation speed of one of the two bobbins when the detected tensile strength is smaller than the predetermined value to yield the hollow fiber-type separation membrane.

Abstract: In a method for making a permeable film, a physical force is applied to a film of a first material containing particles of a second material which is different from the first material. The second material has a higher susceptibility to the physical force than does the first material. Applying the physical force to the film affects the particles which in turn affect the first material of the film, thereby increasing permeability of the film.

Abstract: The present invention is directed to a method of making a foam, the method including contacting a polymer solution with a surface of a mold, the solution containing dissolved therein a biocompatible polymer, the mold containing disposed on at least one surface thereof a three-dimensional negative configuration of a predetermined micropattern to be disposed on and integral with at least one surface of the foam, lyophilizing the solution while in contact with the surface of the mold and removing the lyophilized micropatterned foam from the mold.

Abstract: A method for preventing activation of the contact phase of blood or plasma which comes into contact with a semi-permeable membrane based on polyacrylonitrile bearing fixed negative charges, which is fitted in apparatus for the treatment of blood or plasma, by extra-corporal circulation, said method comprising contacting blood or plasma with said semi-permeable membrane, wherein: a neutral or cationic polymer is combined with said semi-permeable membrane before or after formation of the membrane, and before sterilization of the membrane; the overall ionic capacity of the semi-permeable membrane, based on polyacrylonitrile bearing fixed negative charges and containing a neutral or cationic polymer, is negative; the overall ionic capacity of the semi-permeable membrane, based on polyacrylonitrile bearing fixed negative charges and containing a neutral or cationic polymer, is, as an absolute value, not more than 10% less than the overall ionic capacity of the same semi-permeable membrane without a neutral or cati

Abstract: Systems and methods for the manufacture of reinforced, three-zone, microporous phase inversion membrane having any one of a plurality of different possible pore sizes in any of the three zones from at least a single mother dope batch is disclosed. The systems and methods include formulating at least a single mother batch of dope in a vessel preferably maximizing the non-solvent to solvent ratio for a given weight percentage of polymer for use in a microporous phase inversion membrane production operation to produce three-zone phase inversion membranes having one of a plurality of different predetermined pore sizes in any or all of the three zones. The at least one mother dope batch is controllably formulated in at least one vessel such that the temperature of the dope does not exceed a predetermined maximum mixing temperature and is maintained at a relatively low temperature (lower than the mixing temperature) suitable for storage.

Abstract: Process for producing hydrophobic polyolefinic membranes for gas exchange via thermally induced liquid-liquid phase separation is disclosed. A solution of at least one polyolefin in a solvent system, of a compound A and a compound B having a viscosity less than 60 mPa s, is extruded to form a shaped object. The compound A is a solvent and compound B preferably a non-solvent of the polymer, and the boiling point of compound A is at least 50° C. higher than that of compound B. After the shaped object leaves the die, at least one surface thereof is subjected to an atmosphere promoting evaporation of compound B, and the shaped object is subsequently cooled until the phase separation and solidification of the high-polymer-content phase take place.

Abstract: Disclosed is a rigid fine-celled light-weight foam composition and a method of producing it which has improved retention of liquids by absorption/adsorption which improves the thermal insulation and fire retardant properties of the fine-celled foam particularly suited for use in double walled tanks and hollow canopies, building panels, profiles, and the like.

Abstract: Disclosed is a method for manufacturing a multi-layered, air-gapped sheet of chitosan, which is a novel form of chitosan. For the preparation of a multi-layered, air-gapped sheet of chitosan, chitosan is first dissolved in a weak acidic solution to form a chitosan solution. The chitosan solution is incubated at −5° C. to 50° C. for 1 to 30 days. The chitosan solution is than dried by a freeze-drying process, thermal drying process, or vacuum drying process. In freeze-drying, a freezing the chitosan solution at −10° C. to −60° C. and a heating it at 50° C. to 100° C. under a pressure of 100 Torr to 0.1 Torr are alternately repeated several times for about 10 minutes to about 120 minutes for each freezing or heating process. In thermal drying, a heating the chitosan solution at 50° C. to 200° C. and an incubating it at −5° C. to 50° C. are alternately repeated several times for about 10 minutes to about 120 minutes for each process.

Abstract: The invention relates to the use of water-insoluble, linear polysaccharides as a filtering agent, to a method for producing said filtering agent and to a filtering device. The inventive filtering agent have a high capacity for absorption and retention.

Abstract: Described is a method of forming and curing high internal phase emulsions (HIPEs) into shaped three dimensional foam implements. In general the method uses the steps of: providing a HIPE, depositing the HIPE into a mold cavity having a predetermined three dimensional shape, curing the HIPE in the mold cavity to form a HIPE foam, and stripping the HIPE foam from the mold cavity to form the three dimensional foam implement. The molded implements are widely useful as components in absorbent articles, toys, insulation, and other uses where a combination of low density and tridimensional shape are desired.

Abstract: The present invention relates to a composite semipermeable membrane which is characterized in that it is a composite semipermeable membrane in which there is formed by polycondensation on top of a microporous support membrane a crosslinked polyamide ultra-thin membrane layer from polyfunctional amine, polyfunctional acid halide and polyfunctional acid anhydride halide, and the flow of water permeate at an operating pressure of 0.3 MPa, a temperature of 25° C. and a pH of 6.5 lies in the range from 0.8 to 4.0 m3/m2.day and, furthermore, the percentage humic acid removal is at least 98%; a method for the production thereof; and a water purification method employing same.

Abstract: Porous products of thermoplastic polymers and the like are formed by sintering pellets, especially micropellets and/or pellets made by rapid water quenched pelletizing of the polymers, such as by underwater pelletizing or water ring pelletizing. The pellets are of a uniform size and shape, each having approximately equal dimensions along three mutually perpendicular axes, thereby producing porous products having smooth surfaces, narrow pore size distributions, greater strength and other improved characteristics. The porous products include antiperspirant and deodorant applicator heads, wastewater treatment bubblers and selective filters.

Abstract: A method to efficiently and continuously produce microspheres of natural oils and fats having a high melting point, the average particle diameter of which is in dozens of &mgr;m and is uniform, comprising the steps of heating oils and fats having a high melting point to a temperature greater than the melting point thereof to liquify same holding the oils and fats in a liquid state, forming a dispersed phase of the liquid oils and fats, pressurizing the dispersed phase and forming emulsions by dispersing the dispersed phase into a continuous phase via a plurality of microchannels, and isolating microspheres of the oils and fats having a high melting point by removing the continuous phase from the emulsions.

Abstract: A method for preparing microparticles having a selected polymer molecular weight. The hold time and temperature of a solution containing a nucleophilic compound and a polymer having a starting molecular weight are controlled in order to control the molecular weight of the polymer in the finished microparticle product. In this manner, a selected polymer molecular weight in the finished microparticle product can be achieved from a variety of starting material molecular weights.