348 results about "Hydrophilic membrane" patented technology

The present invention relates to devices, kits, instruments and methods for conducting lateral flow assays. A naturally hydrophilic membrane a fluorescent or luminescent label are used in the present devices, kits, instruments and methods. Preferably, a single naturally hydrophilic membrane and/or a fluorescent or luminescent particle label is used.

A process for imparting hydrophilic properties to a polymeric membrane by exposing the membrane to an acrylate monomer containing hydrophilic segments, such as ethylene oxide, and a hydrophilic functional group, a diacrylate monomer containing hydrophilic functional groups, and an initiator for facilitating crosslinking and polymerization reactions.

A hydrogen generator capable of operating in any orientation and having no moving parts includes a catalyst retaining structure. The catalyst retaining structure is disposed in a housing and serves to separate the housing into a fuel holding portion and a hydrogen chamber. The catalyst retaining structure also includes one or more pores, each pore being in communication with the fuel holding and hydrogen chambers. A catalyst, that promotes the generation of hydrogen gas upon contact with the fuel, is disposed within the pores. The fuel enters the pores and thereupon generates hydrogen gas which passes into the hydrogen chamber. Contact of the fuel with the catalyst in the pores may be controlled and the position of the fuel-hydrogen interface within the pore may be moved so as to regulate the generation of hydrogen. The catalyst retaining structure can take different forms, including one or more hollow elongated members or plates, and may further incorporate hydrophobic and/or hydrophilic membranes.

The invention discloses a dopamine-based method for improving surface hydrophilicity and biocompatibility of a medical polyurethane material. The method comprises the following steps: carrying out pretreatment on a medical polyurethane material by using dopamine so as to obtain a site with proper surface roughness and abundant reaction activity; putting the medical polyurethane material subjected to dopamine pretreatment into hydrophilic membrane concentrate, and carrying out heating reaction for 4-8 hours; and fully cleaning and drying the reaction product. According to the method disclosed by the invention, a layer of film is prepared on the material surface on the basis of the dopamine, and the prepared film has high hydrophily, the blood compatibility can be improved, the damage to tissue is reduced, the film has good stability, and low water contact angle and high hydrophily of a sample can be kept for a long period of time.

The invention relate to a non-crystallization type permanent hydrophilic polyvinylidene fluoride material and the preparation method thereof. The invention adopts crystalline non-crystallization type polyvinylidene fluoride macromolecules, mixes the polyvinylidene fluoride macromolecule with long chain hydrophilic or long chain hydrophilic and noncrystalline hydrophobic macromolecules; thus, the polyvinylidene fluoride macromolecules and water-soluble long chain macromolecules physical cross-linking are formed in polar excellent solvent, and liquid-liquid phase separation is realized via adding micromolecule addictives and improving the temperature of coagulation bath at the same time to speed up the phase separation of the macromolecules; after treatment, the permanent hydrophilic membrane material is obtained, the membrane material is mainly formed by amorphous macromolecule material, the crystallinity of the material is 0 to 0.4; the water contact angle is 0 to 50 degrees with permanent hydrophilicity.

A method of manufacturing a hydrophilic membrane and hydrophilic membranes having improved antifouling property using a supercritical fluid or a subcritical fluid. The method involves combining a coating solution from a hydrophilic group-containing monomer, an initiator, a cross-linking agent and a supercritical fluid or subcritical fluid in a high pressure solution vessel and transferring the coating solution to a membrane in a high pressure coating vessel, coating the surfaces and micropores of the membranes through cross-linking polymerization reactions. Non-reacted coating material is returned to the high pressure solution vessel. The membranes are removed from the coating vessel, cleaned and dried. The hydrophilic membrane manufactured by the present invention is excellent in properties of hydrophobic membranes such as thermal stability, chemical stability and mechanical strength, and surfaces and micropores of the membranes are uniformly coated.

The present invention relates to a preparation method for a microporous membrane having a multi-scale gradient micro-structure surface. The method comprises: fixing a screen mesh on the upper surface of a rough flexible substrate, coating a polymer solution layer with a thickness of 50-500 mum on the upper surface of the screen mesh at a constant speed, curing, washing, and carrying out simple mechanical peeling to remove the rough flexible substrate to obtain the microporous membrane having the multi-scale gradient micro-structure surface. According to the present invention, the process of the method is simple, the membrane area can be controlled, continuous production can be achieved, mechanical properties of the membrane are high, and the membrane has super-hydrophobic or super-hydrophilic property, wherein the super-hydrophobic membrane has super-lipophilic property, and the super-hydrophilic membrane has super-oleophobic property under water and has super-hydrophobic property under oil; and the obtained membrane can be adopted to effectively separate various oil and water mixtures including nano-scale oil water emulsions, and can further be used in fields of self-cleaning ultrafiltration/microfiltration membrane sewage treatments, medical sterilization, food turbidity removal, sterilization, material separation, membrane distillation, and the like.

The invention discloses a reverse osmosis membrane and a preparation method thereof. The reverse osmosis membrane comprises a non-woven support layer, a polysulfone base membrane layer, a polyamide desalination layer and a transition layer, wherein the non-woven support layer is coated with the polysulfone base membrane layer; the transition layer is a hydrophilic membrane layer and is arranged between the polysulfone base membrane layer and the polyamide desalination layer. According to the reverse osmosis membrane, as the hydrophilic transition layer is inserted between the polysulfone base membrane layer and the polyamide desalination layer, the hydrophilic transition layer improves dispersion uniformity of a polyamine solution on the surface of the polysulfone base membrane layer, a binding force of the hydrophilic polyamide desalination layer with the polysulfone base membrane layer is increased greatly, the reverse osmosis membrane is high in desalinization ratio, uniformity and water flux, and long in service life, and can bear at least 0.5 MPa backpressure, and significantly lower engineering cost and manufacturing cost.

The invention discloses a polyvinylidene fluoride hollow fiber ultrafiltration membrane with permanent hydrophilcity and a preparation method thereof. The preparation method comprises the following steps of: sequentially adding 13 wt% to 25 wt% of polyvinylidene fluoride, 8 wt% to 16 wt% of additives and 0.02 wt% to 3.0 wt% of surface active agents and solvents in a dissolving tank, and then stirring for dissolving for 2 to 16 hours at 15 to 90 DEG C to the fully uniform state to prepare that initial membrane casting liquid; sequentially adding initiating agents accounting for 0.1 wt% to 3.5 wt% of polar monomers and the polar monomers accounting for 0.1 wt% to 5.0 wt% of the membrane casting liquid in the membrane casting liquid, and reacting for 1 to 12 hours at 15 to 90 DEG C to prepare hydrophilic membrane casting liquid; and preparing the hydrophilic hollow fiber ultrafiltration membrane by adopting the traditional dry-wet spinning technology. For the hydrophilic polyvinylidene fluoride hollow fiber ultrafiltration membrane prepared in the preparation method, the pure water permeability coefficient is greater than 230 L/m2*hr*0.1MPa, the retention rate of bovine serum albumin (67000MW) is greater than 95.0%, the breaking elongation rate of fibers is greater than 200%, and the fracture pressure is greater than 0.55 MPa. The polyvinylidene fluoride hollow fiber ultrafiltration membrane with permanent hydrophilcity is especially suitable for deep treatment and recycling of waste water, clarification and separation in the fields of biochemical engineering and medicament, and the like.

The present invention relates to an infusion set (10) that provides for continuous air free delivery of liquid to patients undergoing infusion procedures. In particular, the invention provides for an infusion set (10) that prevents air entering the infusion tubing (40) through the drip chamber (20) by using a hydrophilic membrane (21) having a defined wetting time and a defined mean pore size that will provide a defined bubble pressure point under gravitational pull to permit continuous air free infusion liquid flow there-through. The invention further provides for a clip (50) that once closed, no air bubble is able to pass through the hydrophilic membrane (21) due to the adjustment of the roller clamp (60) along the infusion tubing (40) thereby ensuring safe replacement of the infusion bottle during multiple infusion procedures, thus preventing the occurrence of air embolism in patients especially when the drip chamber (20) is empty.

A stable system for producing liquid products such as ethanol, butanol and other chemicals from syngas components contacts CO or a mixture of CO₂ and H₂ with a hydrophilic membrane under anaerobic conditions and transfers these components into contact with microorganisms contained as a biofilm on the membrane. Maintaining the microorganisms as a biolayer on the surface of the membrane facilitates cleaning of the membrane surface that retains the biofilm. In addition the shell gas space that surrounds the membranes may be flooded to reduce or remove the biofilm. Agitation of the liquid, by for example the bubbling of gas in the surrounding shell space, can fully or partially remove the biofilm from the membrane.

The invention provides composite porous membranes comprising a porous hydrophobic substrate coated with difunctional surface-modifying molecules. The difunctional surface-modifying molecules provide a hydrophilic surface without forming branches of interconnected polymer molecules in the pores. The invention also provides a method for making composite porous membranes, such as a composite hydrophilic membrane with reduced concentration of surface modifying molecules required to coat a hydrophobic substrate.

Water vapor is introduced into an inlet air stream (16) of an engine (12), for example, by a pervaporation process through a non-porous hydrophilic membrane (18). A water reservoir (20), which can contain contaminated water, provides a vapor pressure gradient across the hydrophilic membrane (18) into the inlet air stream (16), while the rate of delivery of the water vapor to a cylinder (38-40) is self-regulated by the rate of flow of air across the membrane. The hydrophilic membrane (18) therefore also filters the water from the water reservoir (20) to an extent that pure water vapor is provided to the air inlet stream (16). Delivery of water vapor can nevertheless be controlled using a hood (26) that slides over the hydrophilic membrane to limit its exposed surface area. Alternatively, water vapor is introduced into one or more of the gas streams of a fuel cell by separating the gas stream from the wet exhaust gas stream by a hydrophilic membrane such that moisture passes across the membrane to moisten the gas stream and thereby prevent drying out of the proton exchange membrane.

The invention discloses a waterproof and moisture permeable composite membrane and a preparation method thereof. The waterproof and moisture permeable composite membrane includes a hydrophobic film and a hydrophilic membrane; a thermoplastic polyester elastomer (TPEE) membrane is used as the receiving base, a hydrophobic polymer spinning solution is stretched into nanoscale/sub-micron fibers through the electrostatic spinning nanotechnology, and is deposited on a non-porous membrane to form the composite membrane (hydrophilic membrane and microporous membrane). With adoption of the electrostatic spinning one-step forming method, the preparation technology of the composite membranes is greatly shortened. The preparation technology is simple and practical, and the spinning process is stable and free from contamination. The prepared composite membrane has high adhesive fastness, is applicable to fire control chemical protective clothing fabric, and also can be widely used in individual protective equipment fabric in the industries and fields of metallurgy, petroleum, military, dangerous chemicals, decontamination and the like.

The invention relates to a method for in-situ polymerization and modification of a polyvinylidene fluoride microporous membrane. In the method, polyvinylidene fluoride microporous is dissolved in triethyl phosphate at first to prepare membrane-forming precursor solution, active solution is added into the membrane-forming precursor solution for in-situ polymerization under nitrogen protection, the mixture is kept static for 18-36 hours at the reaction temperature after reaction, membrane casting solution is prepared via deaeration and is processed by a membrane forming machine to prepare a primary membrane, the primary membrane is soaked in a coagulating bath for 0-3 hour(s) and is then transferred into an deionized water bath to be immersed for 1-48 hour(s) so as to be cured into a membrane, the membrane is naturally dried in the air at the room temperature, and thus the dry hydrophilic polyvinylidene fluoride membrane is prepared. The method is environmentally friendly, the reaction conditions are mild, the preparation method is simple, modification and preparation are completed simultaneously, the repeatability is good, the method cannot be limited by the type of the microporous membrane, a high-flux separating membrane can be obtained with no needs for external pore-forming agents, and the prepared microporous membrane is a dry hydrophilic membrane.

The present invention relates to a device for conditioning breathing air comprising a housing (1) provided with an inlet (5) for non treated breathing air and an outlet (6) for the treated breathing air, wherein said housing (1) comprises passive humidifying means (7) and active humidifying means wherein said active humidifying means comprises a water supply inlet (13), a heating device for the supplied water, a membrane (12) having substantial water impermeable and water vapor permeable characteristics, and a heat exchange element (14), characterized by the fact that said membrane (12) is divided into a hydrophilic membrane (12a) and a water vapor permeable and water impermeable membrane (12b), and that said heat exchange element is selected from the group comprising perforated metal plate (14) and/or a heating resistance. The invention further relates to a method for the conditioning of breathing air, comprising the steps of supplying through the inlet opening non treated breathing air, passively humidifying said supplied air through the passive humidifying means, and actively humidifying said breathing air, through the active humidifying means of a device.

The invention relates to polymeric ultrafiltration or microfiltration membranes of, for instance, Halar, PVDF or PP, incorporating PVME or vinyl methyl ether monomers. The PVME may be present as a coating on the membrane or dispersed throughout the membrane or both. The membranes are preferably hydrophilic with a highly asymmetric structure with a reduced pore size and/or absence of macrovoids as a result of the addition of PVME. The PVME maybe cross-linked. The invention also relates to methods of hydrophilising membranes and/or preparing hydrophilic membranes via thermal or diffusion induced phase separation processed.

A hydrophilic semipermeable membrane can include a porous polymeric structure containing a blend of PVDF and hydroxyalkylcellulose. The membrane may be used for ultrafiltration. A method of making a hydrophilic semipermeable membrane can include providing a blend containing PVDF and hydroxyalkylcellulose, forming the blend into a porous polymeric structure, and purifying the porous polymeric structure.

The invention provides a membrane aeration and membrane separation coupled sewage treatment device and method, wherein the hydrophobic membrane for aeration and the hydrophilic membrane for separation are mounted in a common cylinder shaped reactor, forming a membrane aeration and separation reactor, a bioreactor is also arranged on the reflux line, so as to realize circulatory flow of the treated sewage water between the two reactors, thus achieving the coupling of aeration, membrane separation and biological degradation.