52results about How to "The film making method is simple" patented technology

The invention relates to a preparation method for a proton-conducting membrane, and belongs to the technical field of ion exchange membranes. The preparation method is characterized in that dimethyl sulfoxide is adopted to dissolve polyvinylidene fluoride and sodium allylsulfonate monomer containing proton conducting functional group; a flow casting method is adopted to form a membrane on a smooth solid surface through flow casting; the sodium allylsulfonate monomer is initiated to carry out polyreaction; and the products of the polyreaction and polyvinylidene fluoride molecular chain are formed into the proton-conducting membrane of macromolecular interpenetrating network structure. The preparation method can obtain an ion exchange membrane material with ideal proton conductibility, and overcomes the disadvantage that the prior melting mould pressing process cannot prepare homogeneous phase ion exchange membranes; moreover, the preparation method has the advantages of simple technological process, easy industrial scaling up and the like.

The present invention is preparation process of reinforced hybrid organic-inorganic film and belongs to the field of organic-inorganic separating film preparing technology. During the preparation of the reinforced hybrid organic-inorganic film, inorganic precursor is added directly into filming liquid of organic polymer to obtain the mixture film casting liquid comprising organic polymer 10-20 wt%, additive 0-10 wt%, solvent 55-80 wt% and inorganic precursor 0-24 wt%; the film casting liquid is then cured at 25-75 deg.c for 1-2 days before flow casting or spinning; the flow cast or extruded filming liquid is pre-evaporated in the air for 0-120 s before curing in solidification bath in pH 0.4-4 or pH 10-13; and the cured film is further soaked in the solidification bath for 5-25 min and soaked in pure water for 1-2 days. The reinforced hybrid organic-inorganic film has simplified preparation process and high mechanical strength.

The invention relates to a preparation method of a metal-organic framework material / polymer composite proton exchange membrane. The method is characterized by comprising the following steps: dissolving a polymer matrix and a certain amount of metal-organic framework material with an organic solvent and carrying out ultrasonic dispersion to form a uniform membrane liquid; coating the flat and smooth surface of a glass plate with the obtained membrane liquid, and then removing the organic solvent to obtain a composite membrane; and carrying out vacuum drying on the composite membrane for 24 hours to prepare the composite proton exchange membrane for an all-vanadium redox flow battery. The composite proton exchange membrane is smooth in surface; the internal structure of the membrane is regular; the membrane is uniform in thickness and free of a defect; and the thickness is 10-300 microns. The composite proton exchange membrane provided by the invention has excellent vanadium ion permeation blocking ability, keeps excellent proton transfer performance, overcomes the defect of relatively high vanadium ion permeability of an existing all-vanadium redox flow battery membrane, and has the advantages of being simple in preparation process, high in proton transmittance, excellent in vanadium blocking property, excellent in oxidative resistance, easy to industrially amplify and the like.

The invention discloses a method for preparing a nanofiber-based composite nanofiltration membrane by low-temperature reverse interface polymerization, which is characterized in that it comprises: electrospinning a polymer solution to obtain a nanofiber non-woven fabric, which is obtained after cold pressing The nanofiber porous base membrane; the surface of the nanofiber porous base membrane is infiltrated with a low-temperature oil phase monomer solution; then the water phase monomer solution is added for reverse interfacial polymerization reaction; the nanofiber base composite nanofiltration membrane is obtained after heat treatment. The invention reduces the volatilization rate of the oil phase under low temperature conditions by controlling the temperature of the oil phase solution, provides a complete and uniform reaction interface for the reverse interface polymerization, and overcomes the skin layer inherent in the reverse interface polymerization caused by the rapid volatilization of the oil phase Defects and infiltration problems, the thickness, uniformity and density of the functional barrier layer are optimized by controlling the temperature of the oil phase solution and the polymerization parameters of the reverse interface, thereby enhancing the nanofiltration performance of the composite membrane.

The invention discloses a super hydrophobic modification method for polyvinylidene fluoride hydrophobic membranes and belongs to the technical field of membrane separation. The method comprises: preparing membrane casting solution by using polyvinylidene fluoride (PVDF), N,N-dimethylacetamide (DMAC) serving as a solvent and non-solvent low-molecular-weight alcohol and aging the membrane casting solution to form upper membrane solution; preparing membrane casting solution by using PVDF, DMAC, LiCl or / and polyvinyl pyrrolidone (PVP), and aging the membrane casting solution to form lower membrane solution, wherein the PVDF content in the lower membrane solution is higher than that in the upper membrane solution; scraping the lower membrane solution and the upper membrane solution on a glass plate in turn, and placing the glass plate in air at 50 to 75 DEG C and at a water relative humidity of 80 to 100 percent to obtain a primary ecological membrane; and immersing in running water for stripping the membrane and drying to obtain a polyvinylidene fluoride composite film of which the surface is super hydrophobic. In the invention, the method is simple, the process flow is short, the cost is low, and the prepared membrane has high flux and high salt rejection rate.

The invention discloses a composite flat-sheet polysulfone membrane doped with active carbon and nanometer zinc oxide and a preparation method. The preparation steps are as follows: mixing nanometer zinc oxide, active carbon particles, polysulfone and 1-methyl-2-pyrrolidone in a mass ratio of (0.5-1) to 5 to 20 to 100; ultrasonically oscillating and dispersing the components; stirring the mixture until the components are completely dissolved, de-foamed and membrane-pushed; standing the pushed membrane in the air for 15-20 seconds, then soaking the membrane to a water coagulating bath for 20 minutes, putting the soaked membrane to deionized water to soak for 3 days and then taking out the soaked membrane. The composite flat-sheet polysulfone membrane provided by the invention can improve anti-pollution and adsorption performances of the membrane, and further can carry out photocatalysis under ultraviolet irradiation to effectively remove degradation-resistant pollutants in the water.

The invention relates to a carbon dioxide separation membrane with primary amino groups and carbonate groups and a preparation method thereof; preparation of poly(vinylamine-diallyl dimethyl ammonium carbonate) copolymer and polyvinylamine or polydiallyl A blend of dimethyl ammonium carbonate; with polysulfone ultrafiltration membrane as a support, the blend is dissolved in deionized water, stirred and defoamed to obtain a coating solution; dried for a period of time under certain temperature and relative humidity conditions to obtain A CO2 separation membrane with both primary amine groups and carbonate groups. The invention realizes the synergistic coupling effect between different functional carriers: not only the efficiency of the functional carriers is enhanced, but also the disadvantages of various functional carriers when used alone are avoided. Excellent CO2 permeation selectivity performance: For CO2 / N2 mixed gas, under the feed gas pressure of 0.11-2.00MPa, the CO2 permeation rate is (137-1842)×10-6, and the CO2 / N2 separation factor is 23-160 .

The invention discloses a method for preparing a charged nanofiltration membrane by chloromethylated polysulfone. According to the invention, chloromethylated polysulfone is placed in a trimethylamine solution to obtain a positively charged polysulfone material, then the material is subjected to magnetic stirring for 24 h, the positively charged polysulfone material is placed in ethylene glycol monomethyl ether to prepare a casting solution, the casting solution is used for coating the surface of a polysulfone ultrafiltration base membrane, and the base membrane is dried in a temperature scope of 30-40 DEG C to prepare the nanofiltration membrane; under pressure of 1.2 MPa, the nanofiltration membrane has retention rate and flux on sodium chloride and magnesium chloride being 69.3% / 52.6 L.m<-2>.h<-1> and 76.8% / 40.6 L.m<-2>.h<-1>. The film forming material contains a positively charged group, the retention rate of a positively charged dye by the membrane can reach 95% and above, the charged nanofiltration membrane can be used for separating the salt and the positively charged dye, the nanofiltration membrane has the hydrophilic group, and has good anti-pollution performance.

The invention provides a preparation method for separating phenolic organic matter / water thermoplastic pervaporation polymer membrane. Through the synergistic effect of solvent ratio, temperature and solvent volatilization rate, the curing rate of thermoplastic materials is regulated, and pervaporation polymer films with excellent film-forming properties are prepared. The pervaporation polymer membrane prepared by the method has outstanding separation performance in removing phenolic organic matter in water, and its flux and separation factor are superior to the similar separation membranes prepared by the traditional method. The method can better retain the intrinsic properties of the membrane material and maximize the performance of the separation membrane.