32results about How to "Increased permeability selectivity" patented technology

The invention discloses a preparation method of a polyamine nanoparticle self-assembled nanofiltration membrane. Polyamine monomer molecules are adopted as raw materials, polyamine is taken as a bionic adhesive, the polyamine nanoparticles are formed through auto-polymerization in an aqueous solution, and the polyamine nanocomposite nanofiltration membrane is prepared by in-situ self-assembly and interfacial cross-linking on the surface of a porous support membrane. By regulation of the surface self-assembly behavior and the interfacial crosslinking process of the polyamine nanoparticles, the thickness, the crosslinking degree and surface properties of a nano-separation layer can be optimized, and the nanofiltration membrane with high permeation selectivity and good stability can be obtained. The water flux of the nanofiltration membrane in operating pressure of 0.6MPa is 80-150 Lm<-2>.h<-1>, the organic matter molecular interception rate can be as high as 98%, and the inorganic salt ion interception rate is generally lower than 30%. Therefore, the prepared polyamine nano-composite nanofiltration membrane has high separation selectivity and water permeation flux; the preparation method of the membrane is simple, convenient, controllable and low in cost, thereby having good industrial application prospect.

The invention discloses an MOFs (metal-organic frameworks)-cross-linked polyethylene glycol diacrylate mixed substrate membrane, a preparation and an application. PEGDA (polyethylene glycol diacrylate) is selected as substrate membrane materials, MOFs are selected as fillers, and the MOFs-cross-linked polyethylene glycol diacrylate mixed substrate membrane is prepared by ultraviolet crosslinking and curing under induction of photo-initiators. The mixed substrate membrane has remarkable performances (PCO2>160Barrer, alpha CO2/N2>70, alpha CO2/CH4>40) for separating mixed gas of CO2/N2 and CO2/CH4. Compared with a pure cross-linked polyethylene glycol diacrylate membrane, the MOFs-cross-linked polyethylene glycol diacrylate mixed substrate membrane has higher CO2 gas permeability and separation selectivity, and can be applied to purification of flue gas and natural gas.

The invention relates to a uniwafer type bipolar ion exchange membrane and a method for preparing the same. An anion exchange layer and a cation exchange layer of a bipolar membrane are combined on two sides of the same carrier material respectively or the same side of a uniwafer type ion exchange membrane. The preparation method comprises the following steps that: a, according to certain proportion, an evocating agent, a functional monomer, a comonomer, a crosslinking agent and other additional compositions are prepared into a reaction solution of the corresponding ion exchange layer; and b, according to different carriers, the method carries out single side or double side coating treatment, that is the reaction solution is coated on the carrier material with certain thickness; the carrier material is positioned in an ultraviolet source and is radiated so that the carrier material is cured to obtain the ion exchange layer of one side; the other side of the ion exchange layer is coated with another reaction solution, positioned in the ultraviolet source and is radiated and cured, and according to requirements, cured membrane is positioned in a corresponding ionized treating solution and treated to obtain an ion exchange layer; and the bipolar membrane of the uniwafer type ion exchange layer is finally obtained. The voltage drop of two sides of the membrane is reduced; and the method has low cost and rapid reaction speed and is simple and feasible.

The invention discloses a polyvinylamine film with a branched network structure as well as a preparation method and an application of the film. The film consists of a polyethyleneimine modified indianite tube composite and a polyvinylamine substrate in the mass ratio being (0.1-5.0):100. Firstly, polyethyleneimine with a branched network structure is supported on indianite nanotubes with an electrostatic self-assembling technology, then, the polyethyleneimine modified indianite nanotubes and polyvinylamine are blended, a membrane casting solution is obtained and applied to the surface of a microporous filter membrane, and the functional polyvinylamine film with the branched network structure is prepared and has the thickness of 1-100 mu m. By means of the polyethyleneimine modified indianite nanotubes, crystallization of polyvinylamine molecular chains can be reduced, the polyethyleneimine modified indianite nanotubes with the branched network structure are uniformly dispersed in the polyvinylamine film, and a rapid delivery channel is provided for CO2.

The invention discloses a preparation method of an ultra-low-pressure and high-flux metal-organic nano particle assembly nanofiltration membrane. Polyamine molecules and polyoxometalates serve as rawmaterials, dopamine serves as a biomimetic adhesive, and organic nano particle seeds loaded with metal ions are generated in a water solution through oxidation polymerization; the surface of a poroussupport membrane is coated with an aqueous dispersion of the nano particle seeds, and a membrane is formed through assembly; the membrane is soaked with an organic ligand solution, metal-organic nanoparticles are formed on the surface of the membrane, and finally, through interface crosslinking, the high-permselectivity and high-stability metal-organic nano particle assembly nanofiltration membrane is obtained. The metal-organic nano particle assembly nanofiltration membrane prepared by using the preparation method has the advantages that the structure and the characteristics of the membranecan be controlled, the operation pressure is low, the water flux is high, the separation selectivity is high, and the preparation method is simple and suitable for industrialized application.

The invention discloses a preparation method of a mixed matrix membrane material, and belongs to the technical field of membrane materials. Porous MIL-101 (Cr) particles with the particle size of 200-300 nm are prepared by adopting a solvothermal synthesis method, different amounts of MIL-101 are uniformly dispersed in an MOF dispersion liquid by adopting a stirring-ultrasonic treatment method, the formed solution is added into an ethanol/water solution of high polymer polyether block amide, a series of mixed matrix membranes with different composition proportions are obtained by adopting a natural tape casting method. The method comprises the following steps: preparing the MIL-101 (Cr), preparing the MIL-101-coated Pebax membrane and the like. A permeability comparison diagram shows that MIL-101-coated Pebax mixed matrix membranes with different composition proportions have certain permeability selectivity to ethylbenzene/N2, and along with the increase of the doping amount of MIL-101, the permeation rate of ethylbenzene is increased, and the permeability is improved. The method can be used for separating the VOCs-containing waste gas.

The invention discloses a preparation method of a hollow fiber membrane for removing carbon dioxide from natural gas, belonging to the technical field of gas separation membranes. The method comprisesthe following steps: dissolving MOF particles and a high polymer material in a polar organic solvent to prepare a uniformly mixed spinning solution; filtering the spinning solution, carrying out vacuum defoaming treatment, and performing standing at a spinning temperature; spinning the spinning solution by adopting a dry-wet phase inversion method to prepare a mixed matrix hollow fiber membrane;and drying the hollow fiber membrane by adopting a solvent replacement method, and coating the outer surface of the hollow fiber membrane with a silicone rubber layer. According to the invention, theMOF particles are added into the high polymer material; due to the fact that the MOF particles can provide a high specific surface area and a micropore structure, the gas permeability and separation selectivity of the hollow fiber membrane are improved and the permeation selectivity of the hollow fiber membrane is effectively improved through introduction of the MOF particles; and the preparationmethod is simple in process, easy to operate and good in industrial practicability.

The invention discloses a preparation method of an assembled membrane based on triazine porous organic nano particles. The preparation method comprises the following steps: taking a triazine derivative, a 1,2-dicarbonyl compound and an aldehyde compound as reaction monomers, preparing triazine porous organic nano particles in an acetic acid aqueous solution through a Debus-Radziszewski reaction; mixing the triazine porous organic nano particles with cationic polyelectrolyte to prepare dispersion liquid, and preparing the assembled membrane based on triazine porous organic nano particles on thesurface of a porous support membrane through a pressurized deposition filtration-chemical crosslinking method. The prepared assembled membrane has an efficient dye desalination performance and good stability, and can be applied to the application fields of dye purification, wastewater treatment and the like.

The invention belongs to the technical field of gas membrane separation, and provides a preparation method of an MOFs and polymer bicontinuous mixed matrix membrane. The preparation method comprises the following steps: adding inorganic metal salt particles into an electrospinning polymer for electrostatic spinning, then calcining and converting into metal oxide fibers, then taking oxide nanofibers as a self-sacrifice template, growing MOFs in situ through'coordination-replication ', maintaining the balance between template dissolution and MOFs nucleation, and converting the metal oxide nanofiber mat into the MOFs nanofiber mat. Functional small molecules with low molecular weight are polymerized into gaps of the MOFs nanofibers in situ, so that the compact MOFs/PDA mixed matrix gas separation membrane with high air permeability is constructed. The MOFs/PDA can provide a low-resistance rapid transfer path, selective screening of gas molecules is realized, and the prepared gas separation membrane has the characteristics of high permeability, high selectivity and high mechanical strength, so that the application prospect of the membrane is wider.

The invention belongs to the technical field of blended matrix membrane separation, and particularly relates to a MoS2/organic silicon blended matrix membrane, a preparation method and an application thereof, and the method comprises the following steps: preparing organic silicon sol from organic alkoxy silane through a hydrolytic polymerization method; uniformly mixing the MoS2 dispersion liquid with organic silicon sol to prepare MoS2/organic silicon dispersion liquid; and coating the support body with the MoS2/organic silicon dispersion liquid, and calcining to obtain the MoS2/organic silicon blended matrix membrane. The MoS2/organic silicon blended matrix membrane prepared by the method has good H2 permeability and selectivity, and can be applied to separation of hydrogen in mixed gas.

The invention discloses a charged composite nanofiltration membrane based on organic-inorganic nanoparticles and a preparation method of the charged composite nanofiltration membrane. The nanofiltration membrane is composed of a supporting layer and a nanofiltration functional layer, the nanofiltration functional layer is formed by cross-linking cross-linked ionic amphiphilic polymer nanoparticles and inorganic nanoparticles, the ionic amphiphilic polymer nanoparticles are mutually cross-linked, and the inorganic nanoparticles and the ionic amphiphilic polymer nanoparticles are mutually cross-linked; the supporting layer is crosslinked with the nanofiltration functional layer through reactive groups on the surface of the supporting layer; according to the preparation method of the nanofiltration membrane, the nanofiltration membrane in a flat, hollow fiber or tubular form can be prepared, the prepared nanofiltration membrane is high in flux, efficient separation of ions and charged small molecules of different valence states can be achieved through the charge characteristic of the nanofiltration membrane, and the nanofiltration membrane is excellent in pressure resistance and has the potential of treating high-concentration brine; the method has great application value in the fields of seawater desalination, ion separation, sewage treatment, hard water softening, biological medicine, food processing and the like.

The invention provides a preparation method for a high-performance polyimide hollow fiber membrane. The hollow fiber membrane is prepared by using a dry-wet spinning technology, and the mechanical strength and the solvent resistance of the polyimide hollow fiber membrane are improved by using a high-temperature annealing method. When the annealing temperature is close to the glass-transition temperature, the annealing process can improve the tensile strength of the polyimide hollow fiber membrane, and when the annealing temperature is higher than the glass-transition temperature, the tensile strength and the solvent resistance of the polyimide hollow fiber membrane can be obviously improved. The method is simple and effective, and has a good application prospect in the aspect of gas separation.

The invention provides a nitrogen-containing natural gas membrane separation process with low-temperature enhancement of permeation selectivity, and belongs to the field of petrochemical industry. Nitrogen-containing natural gas is subjected to pretreatment such as compression and dehydration, then high-efficiency and high-yield methane concentration is realized through a multi-stage low-temperature membrane process, and commercial natural gas with the nitrogen content being less than 4.0 vol% is produced. According to the separation process disclosed by the invention, the permeation selectivity is remarkably improved by reducing the operation temperature of a membrane, so that the separation efficiency and the methane recovery rate are improved; and through throttling refrigeration of membrane permeation, expansion refrigeration of high-pressure tail gas and compression refrigeration driven by a turbine, sufficient cooling capacity is provided for the low-temperature membrane process, and it is avoided that external energy is consumed to drive a refrigeration system. By adopting the membrane separation process provided by the invention, feed gas with the single power consumption of about 0.22 kWh/Nm<3> and the nitrogen content of about 30 vol% is produced, and the methane recovery rate exceeds 75.0%.

Epitaxial thin films for use as buffer layers for high temperature superconductors, electrolytes in solid oxide fuel cells (SOFC), gas separation membranes or dielectric material in electronic devices, are disclosed. By using CCVD, CACVD or any other suitable deposition process, epitaxial films having pore-free, ideal grain boundaries, and dense structure can be formed. Several different types of materials are disclosed for use as buffer layers in high temperature superconductors. In addition, the use of epitaxial thin films for electrolytes and electrode formation in SOFCs results in densification for pore-free and ideal grain boundary/interface microstructure. Gas separation membranes for the production of oxygen and hydrogen are also disclosed. These semipermeable membranes are formed by high-quality, dense, gas-tight, pinhole free sub-micro scale layers of mixed-conducting oxides on porous ceramic substrates. Epitaxial thin films as dielectric material in capacitors are also taught herein. Capacitors are utilized according to their capacitance values which are dependent on their physical structure and dielectric permittivity. The epitaxial thin films of the current invention form low-loss dielectric layers with extremely high permittivity. This high permittivity allows for the formation of capacitors that can have their capacitance adjusted by applying a DC bias between their electrodes.

The invention discloses a preparation method of a positively charged composite nanofiltration membrane. The preparation method specifically comprises the following steps: (1) preparing a water phase solution; (2) preparing an organic phase solution; and (3) preparing the positively charged composite nanofiltration membrane. Compared with a pure polyethyleneimine nanofiltration membrane, the positively charged composite nanofiltration membrane is higher in permeation selectivity and stronger in anti-pollution capacity.