16994results about "Membranes" patented technology

Novel porous PTFE membranes are described possessing a unique combination of high strength, low flow resistance, and small pore size. Additionally, unique constructions with superior filtration and venting properties incorporating porous PTFE membranes are described.

The present invention is directed to various sets of unit operations for treating aqueous effluents and logic for designing and effecting the treatment. The unit operations include stabilization of subterranean waters, sequential oxidation steps to alter selected target materials, oxidation to break up emulsions prior to removal of the emulsion components, and intense oxidation to break up difficult-to-remove organic target materials.

This invention discloses a cost-effective process for separating contaminants and a wide-range of fouling material from surface water, ground water and from industrial effluents. Having undergone effective pre-treatment, the water can be purified further by using high-surface area spirally wound micro-filtration (MF), ultra-filtration (UF), nano-filtration (NF) or reverse osmosis (RO) membranes. High-quality potable water free from pathogen and other contaminants is thus produced at low-cost from the pre-treated surface water and ground-water. Conversely, pre-treated industrial effluents are further purified at a relatively low-cost using NF or RO membranes, thus producing water suitable for recycle or surface discharge. The process of this invention uses cationic inorganic and / or polymeric flocculants to coagulate and flocculate the water-borne colloidal matter (e.g. clays, iron hydroxides, naturally occurring matter (NOM's), etc.), followed by filtration using a multi-media filter, charge neutralization and reversal and final filtration using a 5-micron cartridge filter. These pre-treatment steps provides a good quality water having a low Silt Density Index and a significant negative zeta potential, thereby ensuring against irreversible chemical fouling of the spirally-wound membranes.

A process for purifying 1,3-propanediol from the fermentation broth of a cultured E. coli that has been bioengineered to synthesize 1,3-propanediol from sugar is provided. The basic process entails filtration, ion exchange and distillation of the fermentation broth product stream, preferably including chemical reduction of the product during the distillation procedure. Also provided are highly purified compositions of 1,3-propanediol.

The present invention is directed to novel systems for conducting the filtration of blood using manifolds. The manifolds integrate various sensors and have fluid pathways formed therein to direct fluids from various sources through the requisite blood filtration or ultrafiltration system steps.

Desalination methods that include carbonate compound precipitation are provided. In certain embodiments, feed water is subjected to carbonate compound precipitation conditions prior to desalination. In certain embodiments, desalination waste brine is subjected to carbonate compound precipitation conditions. In yet other embodiments, both feed water and waste brine are subjected to carbonate compound precipitation conditions. Aspects of embodiments of the invention include carbone dioxide sequestration. Embodiments of the invention further employ a precipitate product of the carbonate compound precipitation conditions as a building material, e.g., a cement. Also provided are systems configured for use in methods of the invention.

The present invention provides drug delivery dressings having a fluid control film component that comprise a sheet having microchannels that permit directional flow of a liquid.

The present invention provides microfluidic devices and methods for using the same. In particular, microfluidic devices of the present invention are useful in conducting a variety of assays and high throughput screening. Microfluidic devices of the present invention include elastomeric components and comprise a main flow channel; a plurality of branch flow channels; a plurality of control channels; and a plurality of valves. Preferably, each of the valves comprises one of the control channels and an elastomeric segment that is deflectable into or retractable from the main or branch flow channel upon which the valve operates in response to an actuation force applied to the control channel.

A composition of enzyme, polymer, and crosslinker forms a network of covalently bound macromolecules. The covalently immobilized enzyme preparation has enzymatic activity, and retains stable activity when dried and stored at ambient conditions. Methods for preparing an immobilized enzyme and methods for using the enzyme are disclosed.

The present invention recognizes that diagnosis and prognosis of many conditions can depend on the enrichment of rare cells from a complex fluid sample. In particular, the enrichment of fetal cells from maternal samples, such as maternal blood samples, can greatly aid in the detection of fetal abnormalities or a variety of genetic conditions. In addition, the present invention recognizes that the enrichment of rare malignant cells from patient samples, can aid in diagnosis, prognosis, and development of therapeutic modalities for patients. The invention includes microfabricated filters for filtering fluid samples and methods of enriching rare cells of fluid samples using microfabricated filters of the present invention. The invention also includes solutions for the selective sedimentation of red blood cells (RBCs) from a blood sample and methods of using selective RBC sedimentation solutions for enriching rare cells of a fluid sample. Yet another aspect of the invention is an automated system for processing a fluid sample that includes: at least one filtration chamber that includes a microfabricated filter; automated means for directing fluid flow through at least one filtration chamber of the automated system, and means for collecting enriched rare cells. The present invention also includes methods of using automated systems for separating rare cells from fluid samples. Preferred fluid samples are blood, effusion, or urine samples, and rare cells that can be enriched from such sample include nucleated red blood cells and cancer cells.

A vertical skein of "fibers", opposed terminal portions of which are held in headers unconfined in a modular shell, is aerated with a gas-distribution means which produces a mass of bubbles serving the function of a scrub-brash for the outer surfaces of the fibers. The membrane device is surprisingly effective with relatively little cleansing gas, the specific flux through the membranes reaching an essentially constant relatively high value because the vertical deployment of fibers allows bubbles to rise upwards along the outer surfaces of the fibers. Further, bubbles flowing along the outer surfaces of the fibers make the fibers surprisingly resistant to being fouled by build-up of deposits of inanimate particles or microorganisms in the substrate provided that the length of each fiber is only slightly greater than the direct center-to-center distance between opposed faces of the headers, preferably in the range from at least 0.1% to about 5% greater. For use in a large reservoir, a bank of skeins is used with a gas distributor means and each skein has fibers preferably >0.5 meter long, which together provide a surface area >10 m2. The terminal end portions of fibers in each header are kept free from fiber-to-fiber contact with a novel method of potting fibers.

A membrane for use in an implantable glucose sensor including at least one crosslinked substantially hydrophobic polymer and at least one crosslinked substantially hydrophilic polymer; wherein the first and second polymers are different polymers and substantially form an interpenetrating polymer network, semi- interpenetrating polymer network, polymer blend, or copolymer. The membranes are generally characterized by providing a permeability ratio of oxygen to glucose of about 1 to about 1000 in units of (mg / dl glucose) per (mmHg oxygen). Three methods of making membranes from hydrophobic and hydrophilic monomers formed into polymer networks are provided, wherein according to at least two of the methods, the monomers may be substantially immiscible with one another.

An ultrafiltration device adapted to be worn on a portion of the body of a patient includes a blood inlet tube leading from a first blood vessel, a blood pump, an anticoagulant reservoir for infusing anticoagulants into the blood, a blood filter including a substrate through which the blood is circulated and filtered, a fluid bag for storing the excess fluid and a blood outlet tube leading to a second blood vessel.

A membrane comprising: (a) a hydrophobic matrix polymer, and (b) a hydrophilic non-ionic polymer, wherein the hydrophobic polymer and the hydrophilic polymer are disposed so as to form a dense selectively proton-conducting membrane. The microstructure of such a membrane can be tailored to specific functionality requirements, such as proton conductivity vs. proton selectivity, and selectivity to particular species.

A process for producing and recovering light alcohols, particularly ethanol, alcohol mixtures containing ethanol, and ABE mixtures (alcohol mixtures containing acetone, butanol and ethanol), using a combination of steps including fermentation, first membrane separation, dephlegmation and dehydration by second membrane separation.

The PRP separator-concentrator of this invention is suitable for office use or emergency use for trauma victims. The PRP separator comprises a motorized centrifugal separation assembly, and a concentrator assembly. The centrifugal separator assembly comprises a centrifugal drum separator that includes an erythrocyte capture module and a motor having a drive axis connected to the centrifugal drum separator. The concentrator assembly comprises a water-removal module for preparing PRP concentrate. The centrifugal drum separator has an erythrocyte trap. The water removal module can be a syringe device with water absorbing beads or it can be a pump-hollow fiber cartridge assembly. The hollow fibers are membranes with pores that allow the flow of water through the fiber membrane while excluding flow of clotting factors useful for sealing and adhering tissue and growth factors helpful for healing while avoiding activation of platelets and disruption of any trace erythrocytes present in the PRP.

The present invention relates to composite solid polymer electrolyte membranes (SPEMs) which include a porous polymer substrate interpenetrated with an ion-conducting material. SPEMs of the present invention are useful in electrochemical applications, including fuel cells and electrodialysis.

Shaped microporous articles are produced from polyvinylidene fluoride (PVDF) and nucleating agents using thermally induced phase separation (TIPS) processes. The shaped microporous article is oriented in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0. The shaped article may also comprise a diluent, glyceryl triacetate. The shaped microporous article may also have the micropores filled with a sufficient quantity of ion conducting electrolyte to allow the membrane to function as an ion conductive membrane. The method of making a microporous article comprises the steps of melt blending polyvinylidene fluoride, nucleating agent and glyceryl triacetate; forming a shaped article of the mixture; cooling the shaped article to cause crystallization of the polyvinylidene fluoride and phase separation of the polyvinylidene fluoride and glyceryl triacetate; and stretching the shaped article in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0.

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.

Porous nanofiber bearing substrate materials are provided having enhanced surface area for a variety of applications including as electrical substrates, semipermeable membranes and barriers, structural lattices for tissue culturing and for composite materials, and the like.

The present invention recognizes that diagnosis and prognosis of many conditions can depend on the enrichment of rare cells, especially tumor cells, from a complex fluid sample such as a blood sample. In particular, the present invention is directed to methods and compositions for detecting a non-hematopoietic cell, e.g., a non-hematopoietic tumor cell, in a blood sample via, inter alia, removing red blood cells (RBCs) from a blood sample using a non-centrifugation procedure, removing white blood cells (WBCs) from said blood sample to enrich a non-hematopoietic cell, if any, from said blood sample; and assessing the presence, absence and / or amount of said enriched non-hematopoietic cell.

A unitary humidity exchange cell (HUX) is dislosed that includes at least one composite membrane, disposed between at least one first chamber for flow of the first fluid therethrough and at least one second chamber for flow of the second fluid therethrough. The composite membrane include an at least partially sulfonated humidity-conducting polymer comprising residues derived from at least one arylvinyl monomer; and a reinforcing substrate bonded thereto. The product finds utility in a variety of physical and chemical processes and products whereby moisture or other highly polar liquid or gas transfer, exchange removal or delivery is important. A notable application is the Membrane Energy Recovery Ventilator (MERV) in which both heat, ions and moisture is transferred between two air streams, one intake and one exhaust, from an air-conditioned building.

A method of making a carbon nanotube structure includes providing an array of substantially aligned carbon nanotubes, wetting the array with a liquid, and evaporating the liquid to form the carbon nanotube structure having a pattern in the carbon nanotube array. The structure is preferably a carbon nanotube foam.

The invention relates to a membrane bioreactor process combined with an advanced biological sludge digestion process that provides significant improvements in sludge digestion by reducing the costs and resources required for disposing of digested sludge. The offline treatment vessel is used to solubilize the organic material by operating in a very low oxygen environment. Digested process fluid is transferred back to the membrane bioreactor. The processes and apparatus substantially reduce the production of waste sludge.

Disclosed herein is a nanostructured material comprising defective carbon nanotubes chosen from impregnated, functionalized, doped, charged, coated, and irradiated nanotubes, and combinations thereof. The defective carbon nanotubes contain a defect which is a lattice distortion in at least one carbon ring. Also disclosed is a method of purifying fluids, such as liquids, including water, as well as gases, including the air using, this nanostructured material.

Shaped microporous articles are produced from polyvinylidene fluoride (PVDF) and nucleating agents using thermally induced phase separation (TIPS) processes. The shaped microporous article is oriented in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0. The shaped article may also comprise a diluent, glyceryl triacetate. The shaped microporous article may also have the micropores filled with a sufficient quantity of ion conducting electrolyte to allow the membrane to function as an ion conductive membrane. The method of making a microporous article comprises the steps of melt blending polyvinylidene fluoride, nucleating agent and glyceryl triacetate; forming a shaped article of the mixture; cooling the shaped article to cause crystallization of the polyvinylidene fluoride and phase separation of the polyvinylidene fluoride and glyceryl triacetate; and stretching the shaped article in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0.

The PRP separator-concentrator of this invention is suitable for office use or emergency use for trauma victims. The PRP separator comprises a motorized centrifugal separation assembly, and a concentrator assembly. The centrifugal separator assembly comprises a centrifugal drum separator that includes an erythrocyte capture module and a motor having a drive axis connected to the centrifugal drum separator. The concentrator assembly comprises a water-removal module for preparing PRP concentrate. The centrifugal drum separator has an erythrocyte trap. The water removal module can be a syringe device with water absorbing beads or it can be a pump-hollow fiber cartridge assembly. The hollow fibers are membranes with pores that allow the flow of water through the fiber membrane while excluding flow of clotting factors useful for sealing and adhering tissue and growth factors helpful for healing while avoiding activation of platelets and disruption of any trace erythrocytes present in the PRP.

Methods are disclosed to de-sulfate saline streams such as seawater, brine from seawater desalination plants, and the like. The disclosed methods can also co-produce de-ionized water and inorganic materials from such de-sulfated saline streams.

A filtration system is provided with hollow membrane filter elements operable to remove solids, particulate and colloidal matter from a process fluid. Acoustic, vibration and ultrasonic energy may be used to clean exterior portions of the hollow membrane filter elements to allow substantially continuous filtration of process fluids. The filtration system may be satisfactorily used with process fluids having a relatively high concentrations of solids, particulate and colloidal matter.