2632 results about "Microporous membranes" patented technology

The invention provides an apparatus and system for ablation of body structures or tissue in the region of the rectum. A catheter is inserted into the rectum, and an electrode is disposed thereon for emitting energy. The environment for an ablation region is isolated or otherwise controlled by blocking gas or fluid using a pair of inflatable balloons at upstream and downstream locations. Inflatable balloons also serve to anchor the catheter in place. A plurality of electrodes are disposed on the catheter and at least one such electrode is selected and advanced out of the catheter to penetrate and ablate selected tissue inside the body in the region of the rectum. The electrodes are coupled to sensors to determine control parameters of the body structure or tissue, and which are used by feedback technique to control delivery of energy for ablation or fluids for cooling or hydration. The catheter includes an optical path disposed for coupling to an external view piece, so as to allow medical personnel to view or control positioning of the catheter and operation of the electrodes. The catheter is disposed to deliver flowable substances for aiding in ablation, or for aiding in repair of tissue, such as collagen or another substance for covering lesions or for filling fissures. The flowable substances are delivered using at least one lumen in the catheter, either from at least one hole in the catheter, from an area of the catheter covered by a microporous membrane, or from microporous balloons.

A method of producing a biocompatible microporous membrane comprising the steps of providing a biocompatible membrane and using an energy beam to form a set of pores having a minor axis of less than 15 μm through the biocompatible membrane. One embodiment includes the steps of producing a first layer of material, defining a first set of pores; producing a second layer of material, defining a second set of pores and wherein the second set of pores is defined so as to cooperatively engage the first set of pores; and aligning and joining the first layer of material to the second layer of material to form a laminated membrane, having through-passageways formed by the first set of pores at least partially aligned with the second set of pores.

Disclosed is an organic/inorganic composite porous separator comprising: (a) a polyolefin-based separator substrate; and (b) an active layer formed by coating at least one region selected from the group consisting of a surface of the substrate and a part of pores present in the substrate with a mixture of inorganic particles and a binder polymer, wherein the inorganic particles in the active layer are interconnected among themselves and are fixed by the binder polymer, and interstitial volumes among the inorganic particles form a pore structure. A method for manufacturing the same separator and an electrochemical device including the same separator are also disclosed. An electrochemical device comprising the organic/inorganic composite porous separator shows improved thermal and electrochemical safety and quality, simultaneously.

The present invention provides a positively charged microporous membrane having a protein binding capacity about 25 mg/ml or greater comprising a hydrophilic porous substrate and a crosslinked coating that provides a fixed positive charge to the membrane. The present invention further provides a positively charged microporous membrane comprising a porous substrate and a crosslinked coating comprising pendant cationic groups. The membranes of the present invention find use in a variety of applications including ion-exchange chromatography, macromolecular transfer, as well as detection, filtration and purification of biomolecules such as proteins, nucleic acids, endotoxins, and the like.

A method is provided for delivering a therapeutic agent to selected sites within an organism. More particularly, the invention allows for the simultaneous delivery of therapeutics to multiple treatment locations from a single catheter using a single pumping source. The catheter utilizes a microporous membrane that allows for the distribution of therapeutic agents from multiple longitudinal positions.

The invention relates to a garment that protects against liquid and/or airborne contaminants and prevents transmission of human body odor. The garment includes a moisture vapor permeable, chemical and water impermeable microporous membrane arranged to form a barrier to chemical and particulate penetration and permeation through the garment. The membrane comprises a thermoplastic polymeric resin material and an activated carbon filler material distributed throughout the membrane and functioning both as a mechanical pore-forming agent for rendering the membrane microporous, and also as an adsorbent to render the membrane odor adsorptive.

A separator membrane for use in silver-zinc batteries is produced by extruding a blend of two fillers with the same chemical formula but different particle size. A polyolefine polymer and a plasticizer are blended and extruded to form a thin sheet of 1 to 10 mil thickness. The plasticizer is then extracted to leave submicron voids in the membrane. Plasticizers are added as processing aids, and can be either soluble or insoluble in water, and include petroleum oils, lubricating oils, fuel oils, and natural oils such as tall oils and linseed oils. The oil are then extracted from the membrane by conventional procedures such as single stage extraction using a suitable solvent. Commercially available wetting agents known to the art such as dodecylphenoxy polyethoxy ethanol and isooctyl phenyl polyethoxy ethanol are coated onto the sheet to improve wettability. The sheet is then dried, and boiled in distilled water for one minute or more, before being finally dried.

A filtering apparatus comprises a microporous membrane and an actuator. The membrane is positioned to traverse across the hollow interior of a conduit used for the transport of molecules in bulk. In one example, the pores of the membrane comprise a plurality of open-ended carbon nanotubes. The actuator comprises a transducing material such as a polyvinyledene fluoride film that is operatively positioned in contact with the membrane and is capable of propagating acoustic vibration onto the membrane at a particular frequency so as to hasten the movement of the molecules through the membrane. Similarly, a method of filtering water comprises the steps of: (a) sifting molecules of water through the membrane, the pores of the membrane comprising a plurality of carbon nanotubes; and (b) propagating acoustic vibration onto the microporous membrane at a libration frequency of ice so as to hasten movement of the water molecules within the carbon nanotubes.

A process is provided for selectively removing protein aggregates from a protein solution in a normal flow (NFF) filtration process. Preferably, it relates to a process for selectively removing protein aggregates from a protein solution in a normal flow (NFF) filtration process and virus particles from a protein solution in a two-step filtration process. In a first step, a protein solution is filtered through one or more layers of adsorptive depth filters, charged or surface modified microporous membranes or a small bed of chromatography media in a normal flow filtration mode of operation, to produce a protein aggregate free stream. The aggregate free protein stream can then be filtered through one or more ultrafiltration membranes to retain virus particles at a retention level of at least 3 LRV and to allow passage therethrough of an aggregate free and virus free protein solution.

An apparatus and system is provided for delivering a therapeutic agent to selected sites within an organism. More particularly, the invention allows for the simultaneous delivery of therapeutics to multiple treatment locations from a single catheter using a single pumping source. The catheter utilizes a microporous membrane that allows for the distribution of therapeutic agents from multiple longitudinal positions.

The invention discloses a porous composite diaphragm for a lithium ion secondary battery and a preparation method thereof. The porous composite diaphragm comprises a polyethylene microporous membrane; and single surface or two surfaces of the polyethylene microporous membrane is/are covered with a heat-resistant coating layer containing heat-resistant resin and inorganic non-conductive insulated particles. Due to use of the composite diaphragm, the mechanical performance, the aperture and the porosity of a base layer can be controlled, the thickness, the aperture and the porosity of the coating layer can be similarly controlled. The diaphragm has the advantages of low hole-closing temperature, high diaphragm-breaking temperature and less heat shrinkage; and the diaphragm used for the lithium ion secondary battery has excellent safety performance.

An implantable drug-delivery device that utilizes a nanopore diffusion membrane in combination with a microporous hydration membrane for achieving long-term, zero-order release of a therapeutic compound or agent. The device comprises a housing, wherein the housing further comprises an interior chamber and at least one aperture passing through the housing; a nanopore membrane in communication with the housing and covering the aperture, wherein the nanopore membrane further comprises a plurality of nanopore channels formed therein and passing though the membrane; a microporous membrane disposed within the housing, the two membranes defining an interface therebetween; a first solvent, e.g., an aqueous medium, disposed within the interface and in communication with both the nanopore membrane and the microporous membrane; and a particulate composition contained within the microporous membrane, wherein the particulates are suspended or buoyant in a second solvent, e.g., a water-immiscible fluid, and wherein the second solvent is in communication with the microporous membrane.

Disclosed is a porous film comprising: (a) a porous substrate having pores; and (b) a coating layer formed on at least one region selected from the group consisting of a surface of the substrate and a part of the pores present in the substrate, wherein the coating layer comprises styrene-butadiene rubber. An electrochemical device using the porous film as a separator is also disclosed. The porous film is coated with a styrene-butadiene polymer, whose rubbery characteristics can be controlled, and thus provides improved scratch resistance and adhesion to other substrates. When the porous film is used as a separator for an electrochemical device, it is possible to improve the safety of the electrochemical device and to prevent degradation in the quality of the electrochemical device.

The invention discloses a hydrophilic polyvinylidene fluoride hollow fiber microporous membrane and the preparation method thereof. The main composition and the mass content of the membrane are 70% to 90% of polyvinylidene fluoride, amphiphilic poly-(propylene oxide-oxirane), 5% to 29% of poly-(methacrylic acid- acrylic acid) or poly-(methacrylic acid methyl ester-vinyl alcohol) copolymer and 1% to 5% of nano-silicon dioxide. The membrane preparation method is that all the components are mixed and dissolved with aperture regulator, thickener and solvent to obtain the membrane preparation liquid; after that, the hollow fiber forming is carried out through a dry-wet spinning technique, and finally cleaning and drying are implemented. The obtained membrane has adjustable internal diameter and external diameter, 60% to 80% of porosity and the aperture ranging from 0.01micron to 0.2micron. As a water disposal separating membrane material with excellent performance, the invention has the advantages of being able to be fully humid, organic adsorption resistance and great water flux, etc.

The invention relates to a polymer nanomicrosphere product with uniform and controllable size and a preparation method thereof. The preparation method comprises the following steps: preparing polymerizable olefine monomers, an initiator, assistants and the like into an oil phase, and preparing water, a stabilizer, an emulsifier and the like into a water phase; and mixing the oil phase and water phase into an O/W pre-emulsion, quickly passing the pre-emulsion through a uniform-pore-size microporous membrane under pressure to form a uniform-particle-size O/W emulsion, and polymerizing and curing emulsion droplets in the emulsion into the uniform-particle-size polymer nanomicrospheres. The average particle size of the microspheres can be controlled within the range of tens of nanometers to 50 micrometers, and the particle size distribution coefficient C.V. is smaller than 20%. The method has the advantages of simple steps, favorable batch repetitiveness, uniform and controllable particle size, no need of subsequent screening and the like, is easy to control, can easily implement large-scale production, and therefore, has the characteristics of fewer emissions and low preparation cost.

The invention discloses a crosslinking polyolefin microporous membrane and a preparation method thereof. Materials for making the membrane mainly comprise 28.8 to 48.8 parts by weight of polyolefin, 30 to 50 parts by weight of cosolvent, 0.1 to 2 parts by weight of peralcohol, 1 to 5 parts by weight of silane, and 0.1 part by weight of antioxygen, and further comprise 0 to 20 parts by weight of ultrafine filler. By the crosslinking of polyolefin, the mechanical strength, the thermal resistance and the tolerance to strong base and chlorine-oxygen compound and other severe chemical environmentsof the polyolefin microporous membrane can be improved, and in practical application, such as an isolating membrane of a lithium ion battery or a filtering membrane in a membrane bioreactor, the service life of the polyolefin microporous membrane can be greatly prolonged.

The invention relates to a method for preparing hydrophilic PVDF microporous barrier. The principal raw material is polyvinylidene fluoride with the range of molecular weight: 5000 to 50000. It prepares hydrophilic PVDF microporous barrier by the method of separating solution and compounding dip-coating modification. It especially suits the occasion of effluent treatment, medicine separation and biochemy. The technology can prepare microporous barriers with plate type and hollow fiber type.

The present invention provides a polyolefin microporous membrane having a surface structure comprising fine spaces formed by partitioning micro-fibrils and a network formed by uniform dispersion of said micro-fibrils, wherein the average diameter of the micro-fibrils is 20 to 100 nm and the average distance between the micro-fibrils is 40 to 400 nm; and a process for producing said poly-olefin microporous membrane.

The battery separator for a lithium battery is made from a nonwoven flat sheet material having high temperature melt integrity, a microporous membrane having low temperature shutdown properties, and an adhesive bonding the nonwoven flat sheet to the microporous membrane and being adapted for swelling when contacted by an electrolyte.

The invention discloses a preparation method of a lithium-ion secondary battery diaphragm with a crosslinking composite layer. The method comprises the following steps of: performing surface treatment on the polyolefin microporous membrane by using solution of strong oxidant to hydroxylate the surface of the membrane; preparing graft solution containing a grafting monomer, an initiator and a solvent; putting the surface-hydroxylated polyolefin microporous membrane into the graft solution and heating the solution in a water bath; in a protective atmosphere of nitrogen, performing graft polymerization on the surface of microporous membrane; preparing a mixed solution of absolute ethanol and water in a ratio of 9:1; and putting the grafted polyolefin microporous membrane and nano inorganic particles into the mixed solution to allow the nano inorganic particles to react with the polymer grafted on the surface of the diaphragm to form a crosslinked structure. The surface of the polyole finmicroporous membrane is modified or hydroxylated by using solution of strong oxidant. The crosslinked layer bonded to the surface of the diaphragm by chemical bonds can act for a long time, so the surface modification is lasting.