130results about How to "Improve gas permeability" patented technology

The invention belongs to the technical field of membranes and in particular relates to a porous material-polymer gas separation composite membrane. The composite membrane comprises a separation layer and a supporting layer, wherein a porous material-polymer hybrid membrane is adopted as the separation layer; one of a porous flat plate and a tubular or hollow fiber membrane is adopted as the supporting layer; the porous material of the separation layer is metal-organic frame materials (MOFs) with large specific surface area and high gas adsorption. The MOFs are added into the separation layer so that the gas permeation and selectivity of the membrane are obviously improved; the separation layer and the supporting layer are compounded so that the membrane keeps good mechanical property, and the separation layer is allowed to exist in a compact or asymmetric structure. The composite membrane provided by the invention has high gas separation property, good mechanical property and wide industrial application prospect.

Disclosed herein are a polyimide dope solution composition, a method for preparing a hollow fiber using the composition and a hollow fiber prepared by the method. More specifically, disclosed are a method for preparing a hollow fiber, comprising preparing a polyimide dope solution composition comprising polyhydroxyimide, polythiolimide or polyaminoimide, spinning the composition to prepare a hollow fiber, and thermally rearranging the hollow fiber, and the hollow fiber prepared by the method.In accordance with the method, a hollow fiber made of a high free volume polymer membrane can be prepared by spinning the dope solution composition to prepare a hollow fiber and thermally rearranging the hollow fiber via thermal treatment. The hollow fiber thus prepared exhibits excellent gas permeability and selectivity, thus being suitable for use as a gas separation membrane.

An object of the present invention is to provide a material which can absorb moisture with ease and certainly, which exists in an equipment such as an electronic device. The invention relates to a moisture absorbing formed body comprising a hygroscopic agent and a resinous component.

The invention discloses a preparation method of a carbon fiber / toughened epoxy resin prepreg for a non-autoclave vacuum bag forming process. According to the method, the dissolution degree and the particle size of a curing agent and a toughening agent in epoxy resin are controlled by controlling a resin formula, the particle sizes of the curing agent and the toughening agent and process conditionsfor resin system configuration, and meanwhile, two modification effects are achieved: 1, the resin system is toughened; and 2, the requirements of a non-autoclave process on the viscosity of the resin in the prepreg and a room-temperature storage period are met. The prepared epoxy resin system is prepared into a rubber film, the carbon fiber / epoxy resin prepreg is further prepared by adopting a rubber film calendering method, and the semi-impregnated prepreg (unsaturated impregnated prepreg) is obtained by controlling the pressure and temperature during compounding of the rubber film and carbon fibers.

The invention provides a semi-aromatic polyimide material, a preparation method and application thereof, and a gas separation membrane containing the semi-aromatic polyimide material. The semi-aromatic polyimide has a structure shown as a formula I, can be used as a gas separation membrane material, and is obtained by synthesizing a diamine monomer I containing an imide chain link from aromatic dianhydride and aromatic or aliphatic diamine, synthesizing a diamine monomer II containing an imide chain link from alicyclic dianhydride and aromatic or aliphatic diamine, and polymerizing the diaminemonomer I and the diamine monomer II under the action of an initiator. The semi-aromatic polyimide molecular chain provided by the invention has a Troger base structure, and the aromatic ring structure in the main chain is matched with the alicyclic structure, so that the gas separation membrane prepared from the semi-aromatic polyimide molecular chain has good mechanical properties and heat-resistant stability, and has a high permeability coefficient and good selectivity when being used for hydrogen separation and air separation.

Disclosed herein are a polyamic acid dope solution composition, a method for preparing a hollow fiber using the composition and a hollow fiber prepared by the method. More specifically, disclosed are a method for preparing a hollow fiber, comprising preparing a polyamic acid dope solution composition comprising polyhydroxyamic acid, polythiolamic acid or polyaminoamic acid, spinning the composition to prepare a hollow fiber, and imidizing and thermally rearranging the hollow fiber, and the hollow fiber prepared by the method.In accordance with the method, a hollow fiber made of a high free volume polymer membrane can be prepared by spinning the dope solution composition to prepare a hollow fiber and thermally rearranging the hollow fiber via thermal treatment. The hollow fiber thus prepared exhibits excellent gas permeability and selectivity, thus being suitable for use as a gas separation membrane.

The invention relates to an adsorption filter material with a multilayer construction, particularly with a permeable adsorptive barrier layer composite, preferably for ABC protective clothing, wherein the adsorption filter material has at least a first barrier layer having a plurality of openings and at least a second barrier layer having a plurality of openings, as well as an adsorption layer disposed between the first and second barrier layers, wherein the first and second barrier layers are disposed in such a manner, that the openings and the openings do not overlap and / or do not coincide. The adsorption filter material is very comfortable and, at the same time, offers excellent protection against chemical poisons.

The present invention generally relates to a crosslinked silane-modified molecularly self-assembling material, cured manufactured article comprising the crosslinked silane-modified molecularly self-assembling material, semipermeable membrane comprising the crosslinked silane-modified molecularly self-assembling material, method of using the semipermeable membrane to separate an acid gas from a separable gas mixture comprising the acid gas and a permeation-resistant gas, and method of preparing the cured manufactured article from a curable manufactured article comprising a shaped reactive silane-modified molecularly self-assembling material.

Provided is a hollow fiber with a structure including a cavity positioned at the center of the hollow fiber, macro-pores present in the periphery of the cavity, and meso-pores and pico-pores present in the periphery of the macro-pores, wherein the pico-pores are connected to each other in a three-dimensional manner to form a three-dimensional network. The hollow fiber contains a polymer derived from a polyamic acid, wherein the polyamic acid includes repeating units prepared from aromatic diamines and dianhydrides containing at least one functional group present in an ortho-position relative to an amine group.

The present invention relates to a method for making an open celled microcellular foam comprising providing at least one foamable polymer and a crosslinking agent in an extruder, injecting at least one blowing agent into said at least one foamable polymer and said crosslinking agent in said extruder, blending said blowing agent injected into said at least one foamable polymer and said crosslinking agent in said extruder, feeding said blended blowing agent, at least one foamable polymer and said crosslinking agent in said extruder to a die, and depressurizing said blended blowing agent, said at least one foamable polymer and said crosslinking agent.

A cycloolefin addition polymer is prepared by addition polymerization of a cycloolefin-functionalized siloxane and optionally norbornene in the presence of catalyst A which is a nickel or palladium complex having a cyclopentadienyl ligand and a methyl, triphenylphosphine or allyl ligand and co-catalyst B, typically tris(pentafluorophenyl)boron or trityltetra(pentafluorophenyl)borate. The polymer is easy to manufacture and has high thermal stability and mechanical strength as well as good gas permeability.

The invention discloses a mixed matrix membrane as well as a preparation method and application of the mixed matrix membrane. The mixed matrix membrane comprises a base material and packing, wherein the base material is polyetherimide and the packing is a molecular sieve; the polyetherimide is selected from one or more of polyetherimide represented by a formula I shown in the specification, wherein A is described in the specification; Z is described in the specification; R is H, CH3 or OCH3; and B is -O-, -CH2-, -CO-, -SO2- or a formula shown in the specification. The mixed matrix membrane takes polyetherimide as the base material so that a polar ether oxygen group in polyetherimide can be sufficiently utilized so as to improve the selectivity of CO2; meanwhile, the molecular sieve with an interconnection pore structure is used as the packing so that the infiltration capacity and the selectivity of gas can be improved and the gas separation performance is excellent. Therefore, the mixed matrix membrane has high selectivity and good gas permeability.

The present invention provides an asymmetric modified CMS hollow fiber membrane having improved gas separation performance properties and a process for preparing an asymmetric modified CMS hollow fiber membrane having improved gas separation performance properties. The process comprises treating a polymeric precursor fiber with a solution containing a modifying agent prior to pyrolysis. The concentration of the modifying agent in the solution may be selected in order to obtain an asymmetric modified CMS hollow fiber membrane having a desired combination of gas permeance and selectivity properties. The treated precursor fiber is then pyrolyzed to form an asymmetric modified CMS hollow fiber membrane having improved gas permeance.

Disclosed is a spiral wound carbon membrane and preparation method thereof. The spiral wound carbon membrane is composed of one or more integral and windable membrane layers composed of a porous support and carbon materials containing fillers filled in the surface, pores and gaps thereof. The spiral wound carbon membrane has a developed ultramicropore porous structure with superior mechanical strength and toughness, and can be directly used to separate a gas mixture with different molecular sizes or liquid mixture.

The invention discloses a modified atmosphere freshness-retaining method for strawberry. Freshly picked strawberry is pre-cooled and put in a packaging container and the mixed gas of oxygen, carbon dioxide and nitrogen is introduced into the packaging container to lead the nitrogen concentration to be 85-95%, the oxygen concentration to be 1-8% and the carbon dioxide concentration to be 1-6%. The packaged strawberry is put in a refrigerator for cold storage at the temperature of 0-2 DEG C. The method leads the strawberry which is liable to oxidation stain to keep fresh and unchanged color and taste within 25 days, thus the product quality is ensured.

Disclosed is a hollow fiber that includes a hollow positioned at the center of the hollow fiber, macropores positioned at adjacent to the hollow, and mesopores and picopores positioned at adjacent to macropores, and the picopores are three dimensionally connected to each other to form a three dimensional network structure. The hollow fiber includes a polymer derived from polyamic acid, and the polyamic acid includes a repeating unit obtained from aromatic diamine including at least one ortho-positioned functional group with respect to an amine group and dianhydride.

The invention discloses a high-performance heat conduction material. The high-performance heat conduction material contains organic silicon resin, hexagonal boron nitride, aluminum oxide, graphene, platinum catalyst, hydrogen-containing silicone oil with hydrogen content of 0.5 to 0.8 percent, silane coupling agent, organosiloxane surface modifier, organic silicone oil and antioxidant 168; the organic silicon resin is low in surface tension, small in viscosity-temperature coefficient, high in compressibility and high in gas permeability, and the hexagonal boron nitride is high in precision and excellent in heat conduction performance and heat radiation performance, so that when the hexagonal boron nitride material is used for preparing an LED heat radiator, a high effect of heat resistance transfer and heat radiation for the LED can be realized; the hexagonal boron nitride and the aluminum oxide are used as heat conduction fillers, so that the cost performance is high; the graphene and the heat conduction fillers are combined with organic silicon resin in the formula, so that the reaction performance of the hexagonal boron nitride in the preparation process can be enhanced through the surface modifier, the compatibility and mechanical properties among the materials can be coordinately improved by virtue of the coupling agent, hydrogen-containing silicone oil and other additives, and a product with high quality and high performance can be obtained.

A room temperature curable organopolysiloxane composition is provided. The composition comprises (I) an organopolysiloxane which is a condensation product of component (A) (an organopolysiloxane comprising R 3 SiO 1 / 2 unit and SiO 4 / 2 unit and containing 0.02 to 0.12 mol / 100 g of hydroxy group bonded to the silicon atom) and component (B) (a diorganopolysiloxane raw rubber having hydroxy group on opposite ends thereof), (II) an organosilane compound having at least 2 hydrolyzable groups bonded to the silicon atom on average per molecule, and / or its partial hydrolytic condensate, (III) a solvent, and (IV) a silica nano particle having its surface modified by a branch structure. The composition is capable of providing a high strength film without incorporating reinforcement fillers, with no curing inhibition by the inorganic nano particles, and without inhibiting gas separation performance realized by the inorganic nano particles.

The invention discloses a modified atmosphere preservation method of spinach. The modified atmosphere preservation method comprises the following steps: (1) the spinach to be preserved is picked and selected; (2) the picked and selected spinach is precooled; (3) the precooled spinach is sterilized; (4) the sterilized spinach is put in a packaging container and the mixed gas of oxygen, carbon dioxide and nitrogen is introduced into the packaging container until the concentration of nitrogen, oxygen and carbon dioxide is 85-95%, 1-8% and 1-6% respectively; (5) after modified atmosphere packaging, the spinach is refrigerated in a cold storage. According to the preservation method disclosed by the invention can, in-vivo breath of the spinach can be restrained, body water of the spinach can be kept and the shelf life of the spinach is prolonged.

The present invention relates to a technology for manufacturing a nanocomposite membrane comprising a graphene oxide coating layer with a thickness of 1 nm to 50 nm, which is formed on various supports and has nanopores, and a reduced graphene oxide nanocomposite membrane, and applying the membranes to gas separation. The graphene oxide nanocomposite membrane for gas separation of the present invention has excellent gas permeability and selectivity at the same time, and especially, excellent hydrogen gas permeability and hydrogen gas selectivity compared with carbon dioxide, and the reduced graphene oxide nanocomposite membrane has remarkably enhanced hydrogen gas permeability and hydrogen gas selectivity compared with carbon dioxide, and thus the membranes are applicable as a gas separation membrane in an industrial field involving a hydrogen separation process. Furthermore, a graphene oxide nanocomposite membrane for gas separation can be provided, in which strong binding force between a support and a graphene oxide coating layer is induced by modifying surfaces of various supports and thus the graphene oxide coating layer is not easily delaminated.

A method for producing an ultra-high-molecular-weight polyethylene porous membrane, including: a step of molding a film using an ultra-high-molecular-weight polyethylene raw material; a step of biaxially stretching the obtained film in X-axis and Y-axis directions at a temperature of from a melting point of the film to 180° C.; and a pore-forming step of stretching the stretched film along at least one axis of the X-axis and Y-axis at from 142° C. to 170° C. Alternatively, a method for producing an ultra-high-molecular-weight polyethylene film, including: a step of molding a film by two steps of press-molding and roll-molding using an ultra-high-molecular-weight polyethylene raw material; and a step of biaxially stretching the film obtained in the above step, in X-axis and Y-axis directions at a temperature of from a melting point of the film to 180° C.

Provided is a hollow fiber with a structure including a cavity at the center of the hollow fiber, macro-pores disposed in the periphery of the cavity, and meso-pores and pico-pores disposed in the periphery of the macro-pores, wherein the pico-pores are connected to each other in a three-dimensional manner to form a three-dimensional network. The hollow fiber contains a polymer derived from a polyimide, wherein the polyimide includes repeating units prepared from aromatic diamines and dianhydrides containing at least one functional group existing at an ortho-position relative to an amine group.

The disclosure provides a porous metal substrate structure with high gas permeability and redox stability for a SOFC and the fabrication process thereof, the porous metal substrate structure comprising: a porous metal plate composed of first metal particles; and a porous metal film composed of second metal particles and formed on the porous metal plate; wherein the porous metal plate has a thickness more than the porous metal film, and the first metal particle has a size more than the second metal particle. Further, a porous shell containing Fe is formed on the surface of each metal particle by impregnating a solution containing Fe in a high temperature sintering process of reducing or vacuum atmosphere, and the oxidation and reduction processes. The substrate uses the porous shells containing Fe particles to absorb the leakage oxygen.

The invention discloses a modified atmosphere preservation method of fresh honey peaches. Precooled fresh honey peaches are put in a packaging container; mixed gas of oxygen, carbon dioxide and nitrogen is introduced into the packaging container until the concentration of nitrogen, oxygen and carbon dioxide is 85-95%, 1-8% and 1-6% respectively. According to the preservation method disclosed by the invention, the problems that honey peaches are extremely difficult to store and the time for preservation is short can be mainly solved, and the refreshing time the honey peaches lasts for as long as 25 days.

To provide a fibrous laminate having excellent secondary processability in processing into a filter or the like by laminating a fibrous layer composed of ultrafine fibers with another fibrous layer and strongly adhering and uniting each interlayer while reduction of characteristics of the ultrafine fibers is suppressed at a minimum to compensate insufficiency of mechanical strength and rigidity of a layer of ultrafine fibers.The fibrous laminate includes fibrous layer I composed of ultrafine fibers having a mean fiber diameter of 10 to 1,000 nm and fibrous layer II composed of thermo-fusible conjugate fibers having a mean fiber diameter of 5 to 100 μm, in which contact points between the ultrafine fibers and the thermo-fusible conjugate fibers are bonded by melting of the thermo-fusible conjugate fibers composing the fibrous layer II, and the fibrous layer I and the fibrous layer II are laminated and united by the formed bonding points.

The invention provides a method for preparing a poly(4-methyl-1-pentene) hollow fiber membrane with a gradient pore structure through coupling of a thermally induced phase separation method and a non-solvent induced phase separation method. The method comprises the following steps: uniformly mixing poly(4-methyl-1-pentene) and a diluent at high temperature, and carrying out extrusion to realize one-shot molding; after the formed mixture passes through an air section, allowing the mixture to enter a cooling bath for cooling so as to realize thermally induced phase separation and non-solvent phase separation; and finally, extracting the diluent to obtain the hollow fiber membrane. The hollow fiber membrane prepared by the method provided by the invention has improved safety, and the thermally induced phase separation process and the non-solvent induced phase separation process in a poly(4-methyl-1-pentene) diluent system are easy to regulate and control, so the poly(4-methyl-1-pentene) membrane with better mechanical strength, gas permeability and plasma infiltration resistance is obtained. The invention also provides the poly(4-methyl-1-pentene) hollow fiber membrane and applicationthereof in the field of artificial membrane lungs.

The invention provides a high-performance non-linear non-ether group doped mixed-matrix film. The high-performance non-linear non-ether group doped mixed-matrix film comprises, by mass, 20 to 100% ofa polymer matrix, 0 to 80% of a main body filling material, and 0 to 50wt% of an auxiliary filling material. The main body filling material is prepared from a material which possesses a non-linear structure and contains groups such as ester groups, nitrile groups, and carbonyl groups, so that uniform dispersion of the auxiliary filling material can be promoted effectively; the plurality of kinds of filling materials are capable of acting in the two aspects of gas dissolvability and diffusivity at the same time, and mixed matrix film gas penetration performance can be improved more effectively;the filling material chain carbon number, i.e. chain length is adjusted, so that the temperature resistance and the penetration performance of the obtained mixed matrix film can be improved. The prepared high-performance non-linear non-ether group doped mixed-matrix film possesses excellent separation performance on acidic gas CO2, SO2 and H2S.

The invention discloses a method for preparing ion exchange SAPO-34 molecular sieve membrane, comprising the following steps of: (1) synthesizing SAPO-34 molecular sieve seeds; (2) loading the SAPO-34 molecular sieve seeds on a porous carrier; (3) synthesizing a SAPO-34 molecular sieve membrane; (4) loading a metal salt with a melting point lower than a roasting temperature in a step (5) on the SAPO-34 molecular sieve membrane; and (5) high temperature roasting to remove a template, and simultaneously carrying out ion exchange to obtain the ion exchange SAPO-34 molecular sieve membrane. By loading metal salts with a low melting point on the surface of the molecular sieve membrane, the method combines two steps: template removal and ion exchange, into one step, thereby simplifying a preparation process of the SAPO-34 molecular sieve membrane, reduces synthesis cost, and simultaneously raising gas separating performance of the SAPO-34 molecular sieve membrane.

The invention discloses a modified atmosphere freshness-retaining method for freshly cut fruits, comprising the following steps that: (1) fresh fruits are selected, cleaned, peeled and cut; (2) the freshly cut fruits after cutting are sterilized; (3) the sterilized freshly cut fruits are subjected to rinsing, color protection and draining; (4) the freshly cut fruits which are subjected to color protection are subjected to centrifugal dewatering; (5) after centrifugal dewatering, the freshly cut fruits are subjected to pre-cooling; (6) after pre-cooling, the freshly cut fruits are put in a packaging container and the mixed gas of oxygen, carbon dioxide and nitrogen is introduced into the packaging container to lead the nitrogen concentration to be 85-95%, the oxygen concentration to be 1-8% and the carbon dioxide concentration to be 1-6%; and (7) after modified atmosphere packaging, the fruits are put in a refrigerator for cold storage. The method aims at leading the freshness-retaining time of freshly cut fruits which are used for a combined fruit plate and are liable to enzymatic or non-enzymatic browning to be kept longer than 7 days.

The invention discloses a hybrid film containing fluorosilicone / silicon rubber, which is prepared by the following steps: (1) mixing vinyltriethoxysilane and hydrogen-containing silicone oil, and dropwisely adding catalyst to react, thereby obtaining a crosslinking agent; (2) weighing silicon rubber, dissolving the silicon rubber in tetrahydrofuran, and dropwisely adding the crosslinking agent and catalyst to carry out crosslinking reaction; (3) adding tridecafluorooctyltriethoxysilane, regulating the pH value of the reaction system to 4.0-4.5, and reacting to obtain a solution containing fluorosilicone / silicon rubber; and (4) pouring the solution on a polyethylene terephthalate rubber sheet to form a film, and stripping the film from the rubber sheet after the solution solidifies, thereby obtaining the hybrid film containing fluorosilicone / silicon rubber. The hybrid film containing fluorosilicone / silicon rubber maintains the advantage of excellent gas permeability in the rubbery-state separation film, greatly increases the oxygen / nitrogen separation coefficient, has favorable film-forming properties and mechanical properties, and solves the problems of poor film-forming properties, low film strength and the like in the existing polymer film material.