18 results about "Nafion membrane" patented technology

The application belongs to the technical field of graphene composite membrane preparation, and specifically discloses a preparation method and application of a Nafion / graphene / PES-liquid Nafion semi-hydrated composite membrane, wherein the preparation method comprises the following steps: attaching copper foil with graphene to a solid Nafion membrane, with the side of the copper foil with better graphene growth quality being in contact with the solid Nafion membrane; performing heat pressing treatment on the device; etching off the graphene on the other side of the copper foil that is not in contact with the Nafion membrane by using a dry etching method; removing the copper foil by using a wet etching method; drying the Nafion / graphene composite membrane at room temperature; immersing a PES porous membrane in liquid Nafion to obtain a PES-liquid Nafion sample; placing the sample in a water vapor environment to perform a semi-hydrated reaction and obtain a PES-liquid Nafion semi-hydrated membrane; and after drying at room temperature, attaching the Nafion / graphene composite membrane to the PES-liquid Nafion semi-hydrated membrane to obtain a Nafion / graphene / PES-liquid Nafion semi-hydrated composite membrane. The semi-hydrated composite membrane prepared by the application can be stably electrolyzed in liquid water for a long time, can enrich heavy water, and can better protect the graphene.

The application discloses an integrated system and method for online observation of stable isotopes of multiple methane emission pathways in rice fields, collects methane gas emitted by plants and non-plant mediation respectively, pre-processes the gas by using a Nafion membrane drying tube and a correction algorithm, realizes continuous measurement of data by using a cavity ring-down spectrum-based analyzer, controls semi-automatic or full-automatic switching of different cavities by using a multi-channel switching and control module, and finally analyzes stable isotope characteristics of plant-mediated and non-plant-mediated emission by using a data processing module combined with a Keeling plot method, so that integrated, continuous and online observation of methane emission pathways in rice fields is realized, and real-time performance, comparability and model verification capability of data are significantly improved.

A method for controllable stepwise reduction of electrocatalytic unsaturated nitro compounds with potential regulation belongs to the field of organic electrocatalysis. In a three-electrode system, an electro-reduced copper nanowire catalyst (ER-Cu / CF) grown on copper foam is used as the cathode, a platinum sheet is used as the counter electrode, and an Ag / AgCl electrode is used as the reference electrode. The two poles of the electrolytic cell are separated by a nafion membrane to form an electrocatalytic reactor. In a neutral electrolyte containing nitro compounds, by adjusting the low direct current voltage, the electrocatalytic unsaturated nitro compounds are controllably stepwise reduced to obtain hydroxylamine intermediates, amino products, and fully reduced products with high selectivity and high yield. In the present invention, the selectivity and yield of the products are very high, it can be carried out at normal temperature and pressure, the operation is simple, green and safe, and the reaction controllability is high; it avoids problems such as low yield, poor selectivity, use of noble metal catalysts and toxic reagents, environmental pollution, and the need for high reaction temperature and pressure in other methods.

The present invention belongs to the field of energy material technology, specifically a PEM water electrolysis membrane electrode based on modified Nafion ionomer and its preparation method. The modified Nafion ionomer provided by the present invention is obtained by doping and modifying Nafion ionomer or solid membrane, denoted as FOH n ‑Nafion ionomer, doped with CF3(CF2) n CH2OH; The present invention modifies the Nafion solution by heating and stirring, and modifies the Nafion membrane by impregnation; the modified ionomer is mixed with the anode catalyst to form a slurry, and the membrane electrode is sprayed to prepare a membrane electrode with better stability than the original Nafion; The present invention effectively improves the stability and use value of the non-precious metal catalyst membrane electrode, and is expected to replace precious metal catalysts, thereby reducing the application cost of PEM. In the PEM test, 1A cm ‑2 The voltage is 1.84V under the current density, and good stability is maintained, and the stable operation is 40 hours, which is 10 times of the original. The modification method of the present invention is simple and suitable for mass production.

The invention relates to the technical field of proton exchange membrane materials and preparation, and particularly discloses an enhanced ether-free skeleton hydrocarbon proton exchange membrane as well as a preparation method and application thereof. The proton exchange membrane comprises an ether-free skeleton polyphenyl high polymer matrix, a sulfonate group grafted to a side chain of the matrix, and a polyether-ether-ketone woven mesh reinforcement layer compounded in the matrix, the ether-free skeleton polyphenyl high polymer is prepared through super acid catalysis one-step polymerization, the sulfonate group is introduced through chemical modification to endow proton conduction capacity, and the polyether-ether-ketone woven mesh cloth is combined with a high polymer matrix through a pouring composite process to improve mechanical performance and stability. According to the invention, the problems of environmental harm, supply chain limitation and high cost of the existing perfluorosulfonic acid membrane are solved, the chemical stability is obviously improved compared with that of the traditional sulfonated polyether ether ketone membrane, and the membrane has more advantages in the aspects of dimensional stability, ion selectivity, vanadium ion permeability and comprehensive electrical property of the all-vanadium redox flow battery compared with a commercial Nafion membrane; and the method has extremely high commercial application value.

The invention discloses a method for preparing a high-quality two-dimensional conjugated metal organic framework (2D c-MOFs). At present, 2D c-MOFs synthesized by using a conventional solvothermal method are generally of a polycrystalline structure, the grain size is small, and research on intrinsic properties of the 2D c-MOFs is hindered. An H-shaped pool is used as a reaction container, an organic ligand and a transition metal salt solution are arranged on the two sides of the H-shaped pool respectively, and a Nafion membrane (cation exchange membrane) is arranged between the H-shaped pool and the transition metal salt solution. By utilizing the selective permeability of the membrane to metal cations, the membrane is diffused to a ligand side and is subjected to coordination reaction, so that nucleation and growth kinetics are accurately adjusted, and high-quality 2D c-MOFs are obtained. The preparation method is simple, convenient to operate, high in universality and suitable for growth of various 2D c-MOFs, the obtained material has high crystallinity and large grain size, and a foundation is laid for revealing an intrinsic structure and expanding application of the material.

The present invention discloses a hydrogen removal catalytic layer, a preparation method thereof, and a PEM water electrolysis membrane electrode having the hydrogen removal catalytic layer. The hydrogen removal catalytic layer is obtained by mixing a chloroplatinic acid solution, a surfactant, and a Nafion resin solution, adding a reducing agent to form a catalyst slurry, adjusting the slurry to a suitable viscosity, and finally spraying or coating and drying to form a film. In the membrane electrode preparation of the present invention, the hydrogen removal catalytic layer is added to allow leaked hydrogen to react with oxygen, thereby reducing the hydrogen concentration in the anode oxygen. The preparation method of the hydrogen removal catalytic layer utilizes in-situ reduction of Pt ions within the Nafion membrane, effectively improving the uniformity of Pt distribution and enhancing hydrogen removal efficiency.

The invention discloses a flow battery composite diaphragm and a preparation method thereof, and belongs to the technical field of flow battery manufacturing. According to the preparation method of the flow battery composite diaphragm provided by the invention, the front and back surfaces of a Nafion membrane are subjected to solvent spraying activation to swell the Nafion membrane, then the swelled surface is coated with a Nafion solution containing a nano material through electrostatic spraying and pre-dried, and an ultrathin blended layer is formed; and then carrying out heat treatment on the composite membrane to obtain the composite diaphragm with a sandwich structure. According to the method, the surface swelling treatment and the electrostatic spraying technology are combined, so that fusion of the coating and the base film is promoted, and layering and nanoparticle agglomeration are prevented; the ultra-thin blending coating with high nano filler content is constructed on the two sides of the Nafion film through electrostatic spraying, the permeability of vanadium ions is reduced, and meanwhile the original conductivity and mechanical performance of a base body are kept.

An amide-containing aromatic diamine has the following structural formula: where Ar is a group with an aromatic ring structure. The preparation method includes the following steps: (1) mixing and reacting components including aromatic diamine, p-nitrobenzoic acid, alkyl phosphoric anhydride and polar aprotic organic solvent; (2) adding carboxylic acid and halogen-free quaternary ammonium salt to the product obtained in step (1) to obtain a mixed solution, which is placed in the cathode cell of an H-type electrolytic cell; the anode cell and the cathode cell are separated by a Nafion membrane; adding the same polar aprotic organic solvent and halogen-free organic electrolyte as the cathode cell to the anode cell of the H-type electrolytic cell, and adding a metal ion-free reducing agent; and conducting the reaction by electrolysis; (3) purifying the cathode reaction solution obtained in step (2) by post-treatment to obtain the amide-containing aromatic diamine. The yield, purity and whiteness of the amide-containing aromatic diamine are higher.

The present invention discloses a method and application for preparing a proton exchange membrane using a polymer chemical vapor deposition technology. The method comprises: placing a substrate on a sample stage of a chemical vapor deposition reactor; arranging a nickel-chromium wire above the reaction stage and heating it to a predetermined temperature; heating an initiator, di-tert-butyl peroxide, a first functional monomer, 1H,1H,2H,2H-perfluorodecyl acrylate, a second functional monomer, methacrylic acid or 4-methyl-5-vinylthiazole, and a third functional monomer, vinylphosphonic acid, to vaporize them and flow them into a reactor; the initiator enters the reactor and is heated and decomposed by the nickel-chromium wire to generate free radicals, thereby initiating a free radical chain polymerization reaction between the monomers; the synthesized polymer is deposited on a substrate material to form a thin film to obtain a proton exchange membrane. The present invention synthesizes a multi-component nanoscale proton exchange membrane on the surface of a Nafion membrane in one step, preparing a proton exchange membrane with high proton conductivity at high temperatures.

The application discloses a method for preparing Nafion-Li or Nafion membrane by array capillary and application thereof in batteries. The research result shows that the array capillary can precisely control the transfer of polymer solution to form a uniform ultrathin liquid film, and on this basis, the dynamic viscosity of the liquid film can be well controlled to inhibit the Marangoni flow and capillary flow caused by liquid evaporation, thereby forming a uniform and ultrathin Nafion-Li or Nafion membrane. The method solves the problem that the prior art cannot prepare an ultrathin and uniform ion-selective membrane. The Nafion-Li or Nafion membrane prepared according to the strategy exhibits high ion selectivity and lithium ion transmission flux in lithium batteries, effectively inhibits the shuttle effect of polysulfides, and improves the coulombic efficiency and energy efficiency of the batteries.

The present invention relates to the field of all-vanadium redox flow batteries and discloses a method for modifying a proton exchange membrane. The method comprises the following steps: synthesizing a hollow TiO2-SO3H nanomaterial, comprising: mixing tetrabutyl titanate (TNB) and polyvinyl pyrrolidone (PVP) in a solvent of ethanol and anhydrous acetic acid, vigorously stirring, and then calcining to obtain solid TiO2; subjecting the solid TiO2 to a hydrothermal reaction in a NaOH solution to form a hollow TiO2; and subjecting the hollow TiO2 to a sulfonation reaction in a H2SO4 solution. By introducing the TiO2-SO3H@PMoA nanocomposite into a Nafion membrane, the proton conductivity of the membrane is significantly improved, reaching a proton conductivity of 200-300 mS / cm. This method maintains efficient proton conduction while ensuring the membrane's overall vanadium resistance, making it suitable for all-vanadium redox flow battery applications at high current densities.

The invention relates to the technical field of fuel cells and polymer composite materials, and particularly discloses an organic-inorganic composite filling cross-linked proton exchange membrane and a preparation method thereof. According to the proton exchange membrane, bacterial cellulose is used as a three-dimensional porous framework, the surface of the bacterial cellulose is coated with a silicon dioxide, titanium dioxide or zirconium dioxide inorganic oxide layer in situ, and sulfydryl active sites are introduced through a sulfydryl-containing silane coupling agent; then, under ultraviolet irradiation, sulfydryl and 2-acrylamide-2-methyl propane sulfonic acid (AMPS) are subjected to a sulfydryl-alkene click reaction, a poly PAMPS continuous network covalently crosslinked with the inorganic framework is formed, pores are filled with the poly PAMPS continuous network, and a three-in-one composite structure with the organic framework, the inorganic enhancement layer and the sulfonic group conduction phase is constructed. Compared with the existing Nafion membrane or pure PAMPS membrane, the membrane disclosed by the invention has high proton conductivity, excellent mechanical strength, low swelling property and good chemical resistance stability, and is suitable for electrochemical devices such as fuel cells, water electrolysis hydrogen production and the like.

The invention relates to an underwater fuel cell technology, in particular to a single cell and a hydrogen fuel cell system with the same. Comprising an anode plate, a proton exchange layer and a peroxide layer which are sequentially arranged from front to back, a hydrogen inlet and a hydrogen outlet are formed in the left side and the right side of the anode plate respectively, and gas inlet flow channels are formed in the front end face and the rear end face of the anode plate, so that the gas inlet flow channels are arranged in a double-face mode; two openings are formed in the exchange layer and are respectively communicated with the hydrogen inlet and the hydrogen outlet, and hydrogen firstly enters through the hydrogen inlet. And the power generation process depends on the oxygen selection effect of the PTFE oxygen permeation membrane and the proton conduction of the Nafion membrane, so that a sustainable development scheme without an oxygen bottle is realized, and the practicability of underwater application is remarkably improved. And particularly, the PTFE film is used, so that the system is suitable for energy supply of underwater platforms such as submersible and deep sea detection equipment.

The application provides a low-loading IrO2 electrolytic water membrane electrode, a preparation method and application thereof, and the preparation method comprises the following steps: S1, dispersing iridium dioxide and a polymer in a mixed solution to obtain a spinning precursor solution; the mixed solution comprises a Nafion solution, water and isopropyl alcohol; S2, performing electrostatic spinning on the spinning precursor solution to obtain an IrO2 nanofiber layer; S3, performing hot pressing transfer printing on the Nafion membrane to form an anode catalytic layer; S4, spraying a cathode catalyst slurry on the other side of the Nafion membrane, and performing hot pressing to form a cathode catalytic layer, and finally obtaining the low-loading IrO2 electrolytic water membrane electrode. The low-loading IrO2 electrolytic water membrane electrode with high ordering degree, uniform and controllable fiber diameter and uniform catalyst particle distribution is constructed, the utilization rate of the catalyst is improved while the loading of the noble metal catalyst is reduced, the three-phase interface of the membrane electrode is enlarged, and the high activity is achieved in water electrolysis catalysis.

The invention discloses a sulfonated polyaryletherketone proton exchange membrane and a preparation method thereof, and belongs to the technical field of fuel cells, and the method comprises the following steps: synthesizing a BDHPM monomer, carrying out polycondensation, bromination, phosphonic acid grafting and sulfonation to obtain PhSPAEK-x, carrying out composite membrane casting with 2-methylimidazole, annealing, and carrying out sulfuric acid protonation and strong phosphoric acid doping to prepare a PA / MeIm-PhSPAEK-x membrane. According to the membrane, PhSPAEK-x is used as a matrix, imidazole and phosphoric acid are compounded, a phosphoric acid pool is formed inside, the maximum power density is larger than or equal to 118 mWcm <-2 > under 130 DEG C / 20% RH, the maximum power density is larger than or equal to 487 mWcm <-2 > under 80 DEG C / complete humidification, the phosphoric acid retention rate is larger than or equal to 50%, and the thermal decomposition temperature is gt; the temperature is 400 DEG C; the membrane is simple in preparation process, low in cost and free of fluorine pollution, can replace a Nafion membrane and is suitable for proton exchange membrane fuel cells.

The present invention belongs to the technical field of fuel cells, and discloses an application of a hydrogen-bonded organic framework material in the preparation of a proton exchange membrane for a fuel cell. The proton exchange membrane is a composite membrane formed by dispersing the hydrogen-bonded organic framework material in Nafion. The chemical formula of the hydrogen-bonded organic framework material is [(CN<subgt;3< / subgt;H<subgt;6< / subgt;)<subgt;2< / subgt>(C<subgt;10< / subgt>O<subgt;8< / subgt>H<subgt;4< / subgt>). The proton conductivity of the composite membrane composed of the hydrogen-bonded organic framework material of the present invention is higher than that of a commercial Nafion membrane, which helps to realize the large-scale commercial application of proton exchange membrane fuel cells. Moreover, the hydrogen-bonded organic framework material of the present invention is crystalline, which is beneficial to exploring the proton transport mechanism of the proton exchange membrane.

The invention relates to the technical field of electrochemical energy storage of all-vanadium redox flow batteries, in particular to an ultrathin PBI / Nafion composite membrane as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) dissolving polybenzimidazole powder in a solvent A to obtain a PBI spin-coating solution; and (2) dipping the Nafion membrane in a solvent B for swelling, spreading the Nafion membrane on a carrier, coating the surface of the swelled Nafion membrane with the PBI spin-coating liquid in a rotating state, and drying to obtain the ultrathin PBI / Nafion composite membrane. The composite membrane prepared by the method can be applied to the all-vanadium redox flow battery, can be used as an ion exchange membrane of the all-vanadium redox flow battery, can effectively inhibit permeation of vanadium ions, improves coulombic efficiency and charge-discharge capacity retention rate of the all-vanadium redox flow battery, and prolongs the cycle life of the all-vanadium redox flow battery.