664 results about "Nafion" patented technology

A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various thermoplastc polymers for high temperature polymer electrolyte fuel cells have also been developed. Miscible blends are used for solution casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes. With the thermally resistant polymer, e.g., polybenzimidazole or a mixture of polybenzimidazole and other thermoplastics as binder, the carbon-supported noble metal catalyst is tape-cast onto a hydrophobic supporting substrate. When doped with an acid mixture, electrodes are assembled with an acid doped solid electrolyte membrane by hot-press. The fuel cell can operate at temperatures up to at least 200° C. with hydrogen-rich fuel containing high ratios of carbon monoxide such as 3 vol % carbon monoxide or more, compared to the carbon monoxide tolerance of 10-20 ppm level for Nafion®-based polymer electrolyte fuel cells.

Disclosed is a non-noble metal catalyst for oxygen reduction. The catalyst comprises a flake-like graphene carrier; a nitrogen-doped carbon skeleton arranged between neighbor flake layers of the flake-like graphene carrier; the graphene flake layers are separated by the nitrogen-doped carbon skeleton; and nanometer particles are adhered to the flake layers of graphene. The nanometer particles are one or more than two of carbon-coated non-noble metal particles, carbon-coated non-noble metal carbide particles, and carbon-coated non-noble metal nitride particles. A preparation method of the non-noble metal catalyst for oxygen reduction comprises: adding graphite oxide and non-noble metal precursor salt into water; performing mixing and standing; adding nitrogen-containing micro-molecules, a Nafion solution, and an oxidizing agent; performing uniform mixing; allowing the obtained solution to be evaporated; performing freeze-drying; and performing temperature programming thermal treatment and other after-treatment to obtain the non-noble metal catalyst for oxygen reduction. The catalyst has advantages of high oxygen reduction activity, good mass transfer performance, and low price.

A microfluidic acoustic-based cell lysing device that can be integrated with on-chip nucleic acid extraction. Using a bulk acoustic wave (BAW) transducer array, acoustic waves can be coupled into microfluidic cartridges resulting in the lysis of cells contained therein by localized acoustic pressure. Cellular materials can then be extracted from the lysed cells. For example, nucleic acids can be extracted from the lysate using silica-based sol-gel filled microchannels, nucleic acid binding magnetic beads, or Nafion-coated electrodes. Integration of cell lysis and nucleic acid extraction on-chip enables a small, portable system that allows for rapid analysis in the field.

The invention relates to a lithium negative electrode protection film, a preparation method and a lithium metal secondary battery, belonging to the field of lithium metal secondary batteries. The lithium anode protective film is composed of lithium salt, ionic liquid, inorganic nanoparticles and lithium-treated Nafion polymer. Ionic liquids containing lithium salts are adsorbed on the surface of inorganic nanoparticles and uniformly dispersed in lithium-treated Nafion polymers. By arranging a mixed solution of lithium salts and ionic liquids; Mixing the mixed solution and the inorganic nanoparticles by sealed ball milling to obtain a quasi-solid electrolyte; The quasi-solid electrolyte is mixed with a lithium-treated Nafion polymer solution, coated on the surface of lithium or copper foil,and the protective film is prepared after the solvent is completely volatilized. As that lithium negative electrode protective film can inhibit the generation of lithium dendrite, the lithium negative electrode protective film has good mechanical properties and chemical stability, high lithium ionic conductivity and good film for performance; A lithium metal secondary battery provide with that lithium anode protective film has excellent electrochemical performance.

The invention relates to a novel ordering membrane electrode and a preparation method and application thereof. The membrane electrode consists of a composite electrolyte membrane and a catalyst layer. The composite electrolyte membrane is a proton exchange membrane modified by Pd metal or Pd-Cu alloy or Pd-Ag alloy or Pd-Ni alloy or Pd-Ag-Ni alloy, the catalyst layer is an ordering catalyst layer which comprises a composite electrolyte membrane metal layer consists of conducting polymer nanowires distributed on the surface in an ordering array mode and Nafion self-assembled Pt-PDDA catalyst adhered to the surfaces of the conducting polymer nanowires. The novel ordering membrane electrode has the advantages of being low in Pt bearing capacity, high in utilization rate and the like and can effectively reduce the cost of a fuel-cell catalyst. In addition, the novel ordering membrane electrode can enhance mass transfer of fuel in the catalyst layer while effectively reducing liquid fuel penetration and accordingly improves the fuel utilization rate.

A new class of hybrid organic-inorganic materials, and methods of synthesis, that can be used as a proton exchange membrane in a direct methanol fuel cell. In contrast with Nafion® PEM materials, which have random sulfonation, the new class of materials have ordered sulfonation achieved through self-assembly of alternating polyimide segments of different molecular weights comprising, for example, highly sulfonated hydrophilic PDA-DASA polyimide segment alternating with an unsulfonated hydrophobic 6FDA-DAS polyimide segment. An inorganic phase, e.g., 0.5–5 wt % TEOS, can be incorporated in the sulfonated polyimide copolymer to further improve its properties. The new materials exhibit reduced swelling when exposed to water, increased thermal stability, and decreased O₂ and H₂ gas permeability, while retaining proton conductivities similar to Nafion®. These improved properties may allow direct methanol fuel cells to operate at higher temperatures and with higher efficiencies due to reduced methanol crossover.

A liquid organic, fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion™. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon™-binder structure is immersed within a Nafion™/methanol bath to impregnate the electrode with Nafion™. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.

The invention discloses a preparation process of a hydrogen fuel battery membrane electrode, and belongs to the field of battery membrane electrodes. The membrane electrode is prepared by the aid of an ultrasonic spraying process and a heat transfer printing process. The preparation process includes the steps: firstly, sequentially spraying a transfer printing medium with carbon powder slurry, electric catalyst slurry and binding agent slurry by the aid of the ultrasonic spraying process; secondly, loading a catalyst layer on a proton exchange membrane by the aid of the heat transfer printing process; finally, performing hot-pressing for self-made diffusion layers by the aid of the ultrasonic spraying process to obtain the membrane electrode. According to the preparation process, the diffusion layers are closely combined by the aid of actions among Nafion slurry, the proton exchange membrane and carbon powder slurry and the diffusion layers, electrochemical performance of the membrane electrode is greatly improved by the aid of the heat transfer printing process, the service life of the membrane electrode is prolonged, the problems such as wrinkle and swelling of the proton exchange membrane are solved, a lot of time for paving and treating the membrane is saved, and mass production of the membrane electrode is facilitated.

The invention relates to a preparation method for an ordered ultra-thin electrode of a proton exchange membrane fuel cell. The preparation method comprises the steps of preparing an ordered electrode structure and establishing an ultra-thin catalyst layer; a process of impregnating and annealing is carried out on a carbon paper to obtain TiO<2> seed crystals; then a TiO<2> nanorod is grown through a hydrothermal method; a TiN ordered array is prepared through NH<3> etching; and the array is loaded with a catalyst to establish the ordered ultra-thin catalyst layer without containing a proton conductor (such as Nafion). The established ordered ultra-thin catalyst layer can be used for the proton exchange membrane fuel cell, other fuel cells and electrochemical devices.

The invention discloses a method for preparing perfluoro sulfonic resin with abandoned ion exchange membrane in alkali-chloride industry, comprising following steps: swelling said abandoned ion with lower alcohol, emulsifying it with emulsion machine to resin particle, adding alcohol/ water solvent and resin particle into autoclave, dissolving resin particle under high temperature and pressure and protection of nitrogen; getting solid mixture of perfluoro sulfonic resin and solution, separating with solid-liquid separation method and getting perfluoro sulfonic resin solution and solid perfluoro sulfonic resin. The resin solution is characterized by transparent, low content of foreign matter, high purity, similar property to that of Nafion EW 1100 solution, usage in field of mending ionic membrane pinhole and other mechanical damage, preparation of fuel battery proton exchange membrane and stereoscopic electrode and chemical catalysis.

The invention discloses a preparation method of a hydrogen evolution electric catalyst based on a metal-organic framework compound. The method includes the following steps that 1, cupric acetate aquo-complex Cu (OAc) <2>H<2>O is dissolved in acetic acid for preparing a cupric acetate solution; 2, trimesic acid (H<3>BTC) particles are dissolved in absolute ethyl alcohol for preparing a trimesic acid solution; 3, the trimesic acid solution is transferred to and mixed with the cupric acetate solution; 4, the mixed solution is subjected to ultrasonic operation; 5, the mixed solution is placed in a centrifugal tube for centrifugal operation and activating treatment; 6, a centrifugal product obtained after activating treatment is placed in a drying oven for being dried; 7, after samples and organic solvent are mixed according to proportion, the Cu-MOF@Nafion hydrogen evolution catalyst is obtained. The obtained Cu-MOF@Nafion hydrogen evolution catalyst has unique physical properties of good transmission protons, good electrochemical stability is achieved, efficiency of a hydrogen evolution reaction can be improved, and the recycling service life can be greatly prolonged.

The invention discloses a method for preparing a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) composite modified electrode. The method comprises the following steps of: uniformly mixing PEDOT:PSS aqueous dispersion liquid and Nafion, which are taken as raw materials, and then directly dispensing a mixture on the surface of a composite modified electrode; and in the conventional three-electrode system, performing secondary electrochemical doping by using hydrophobic ionic liquid, and thus obtaining the PEDOT:PSS composite modified electrode which is high in water resistance and high in conductivity. The PEDOT:PSS composite modified electrode which is prepared by the method fully combines the film-forming property of the PEDOT:PSS aqueous dispersion liquid, the adhesion characteristic, biological compatibility and anti-interference characteristic of the Nafion, high conductivity and hydrophobicity of the ionic liquid and the electrochemical catalysis characteristic of a nanometer material, can be applied to electrochemical biosensors or electrochemical sensors, is directly applicable to electrochemical detection of auxin, roxithromycin, vitamin C, benzenediol isomer, organophosphorus, glucose, hydrogen peroxide and the like, and has the characteristics of good detection effect, short response time, high water resistance, wide linear range, high sensitivity, high anti-interference, high stability and the like.

The invention discloses a micro direct methanol fuel cell membrane electrode and a preparation method thereof, and relates to a fuel cell and a preparation method thereof. The membrane electrode comprises an anode diffusion layer, an anode catalyst layer (3), a proton exchange membrane, a cathode catalyst layer (5) and a cathode diffusion layer, wherein the cathode catalyst layer (5) includes an inner layer (5a), an intermediate layer (5b) and an outer layer (5c); the outer layer (5c) is nearest to the cathode diffusion layer; and the inner layer (5a) is nearest to the proton exchange membrane. The preparation method comprises the following steps: taking carbon paper or carbon cloth as a supporting layer, then coating the diffusion layer formed by a carbon material, polytetrafluoroethylene and the like, coating a size formed by a catalyst, Nafion resin, a pore forming substance and the like for several times, and performing heat treatment and pressing to form the membrane electrode. The micro direct methanol fuel cell membrane electrode can inhibit the water permeation of the proton exchange membrane, enhance the splashing effect from the cathode to the anode, and improve the gas diffusion mass propagation speed.

The invention provides a preparation method of a high-performance and voltage-reversal-resistant membrane electrode assembly. The method comprises the following steps: 1. sequentially adding a catalyst, an anti-reversal-electrode electrolyzed water catalytic material and a proper amount of nafion solution into a beaker, carrying out stirring for 10 minutes, adding a dispersing agent, and carryingout uniformly dispersing to obtain anode slurry; 2, spraying the anode slurry on the anode side of a proton exchange membrane; 3, adding a catalyst and a proper amount of nafion solution into a beaker, carrying out stirring for 10 minutes, adding a dispersing agent, and uniformly dispersing to obtain cathode slurry; 4, spraying the cathode slurry on the cathode side of the proton exchange membraneto obtain the required CCM; 5, applying 70kg/cm < 2 > of force to the prepared CCM, the gas diffusion layer and the polyester frame through an oil press, and performing hot pressing to prepare MEA; and step 6, assembling the prepared MEA into a single battery, and carrying out performance test and anti-reverse pole test. According to the invention, the anti-reverse-pole electrolytic water catalytic material is added into the anode catalytic layer, so that reverse poles caused by gas shortage can be effectively reduced.

The invention provides an electrochemical detection method for detecting trace heavy metal ions in water with a modified graphene oxide composite modified electrode. The method includes the steps that graphene oxide is ultrasonically dispersed into a Nafion solution containing bismuth, and GO-Bi-Nafion suspension is obtained; the polished, cleaned and dried surface of a glassy carbon electrode is uniformly coated with the GO-Bi-Nafion suspension, and a GO-Bi-Nafion/GCE is obtained. The developed graphene oxide material meets the requirements for detection and deep removal of heavy metal ions in water. The electrode material with high electrochemical activity has the advantages that sample treatment is easy, cost is low, the speed is high, and trace heavy metal can be detected when applied to electrochemical transducer rapid determination of heavy metal in water. In addition, the development of the heavy metal water pollution detection and treatment technology in China is promoted by the electrochemical detection method, and the modified graphene oxide composite modified electrode will have great economic and social benefits after industrialization.

The invention discloses a method for preparing an enzyme electrode with an MWCNTs-TiO2/Nafion composite medium. In the method, MWCNTs-TiO2 core-shell nanocomposite materials are scattered into Nafion to prepare an organic-inorganic composite membrane as a fixed matrix for biological molecules for structuring a hemoglobin electrode, and a hemoglobin biosensor with fast response, high sensitivity and strong catalytic capacity is prepared by using the properties of large specific surface area, high surface reactivity, strong adsorption capacity, large electrical conductivity and the like of the MWCNTs-TiO2 core-shell nanocomposite materials and the properties of membrane forming, high chemical stability, high anti-interference capacity and the like of the Nafion. The biosensor has good biocompatibility, stability and repeatability, and has potential application in structuring biosensors. The sensor can be used for detecting the substances of hydrogen peroxide, trichloroacetic acid and the like, and has the advantages of low sensitivity, low detection limit and the like.

The invention provides a Pt nano particle-carbon nano tube composite material, a method and an application thereof. The invention is characterized in that ammonia is used for pretreating the carbon nano tube; the carbon nano tube pretreated by the ammonia, sodium citrate, chloroplatinic acid and methanol are used as raw materials; and Pt nano particles are reduced on the outer wall of the carbon nano tube in situ. The weight ratio of the carbon nano tube and chloroplatinic acid, the proportion of the methanol and the sodium citrate and the types of carbon nano tube are improved to obtain the Pt nano particles with smaller particle size and even distribution to wrap the carbon nano tube. The composite material is dispersed in Nafion solution, the mixed solution is dripped on a glassy carbon electrode for natural drying and a thin film modified electrode can be prepared. The electrode has excellent electrocatalytic performance to oxidation reaction of H2O2 and methanol. The method has simple technique, convenient operation, low cost and easy obtaining for the used raw materials, has good application prospect in the electrocatalytic biological sensor and a methanol fuel battery and is applicable to industrial production.

The invention discloses a method for preparing the anode of a microorganism fuel battery with a graphene and ferrous disulfide compound, and belongs to the field of environments, materials and energy. The method comprises the following steps: (1) gradually dropping a ferric trichloride and thiourea solution into a graphene oxide dispersion in a reaction kettle one droplet by one droplet, uniformly stirring, sealing the reaction kettle, and performing hydrothermal reaction for 12-24 hours within 140-200 DEG C so as to obtain a hydrogel sample; (2) washing the hydrogel sample for times with deionized water, performing freeze-drying, and crushing so as to obtain a nano powder of the graphene and ferrous disulfide compound; (3) mixing the nano powder with a 5% nafion solution, isopropanol and deionized water, uniformly oscillating, coating carbon cloth with the solution, fixing the carbon cloth with a fixing part, and drying the carbon cloth in air, so as to obtain the anode. The method has the advantages that the synthesis steps are very simple, obtained particles are uniform in morphology, graphene lamellas are overlapped to form a well-developed porous structure, good electrochemical properties and biocompatibility can be achieved, and the anode of the microorganism fuel battery has very good properties.