2124results about How to "Shape is easy to control" patented technology

The invention relates to compound millimicron fibrous membrane material of cellulose and cellulose matrix which can perform the biological degradation and the biological absorption and a preparation method thereof and an industry and medical purpose, and belongs to the biological macro-molecule non woven fabric material field which can perform the biological degradation and the biological absorption. Electrostatic spinning equipment is used to obtain the fibrous membrane material which can perform the biological degradation and the biological absorption, the weight of the cellulose is taken as basic reference, the component of the material comprises cellulose more than 0 and less than or equal to 100 weight parts, other biomacromolecule more than and equal to 0 and less than 100 weight parts, 0 to 10 weight parts of curative drug or 0 to 50 weight parts of inorganic catalyzer and / or 0 to 50 weight parts of inorganic strengthening agent. The material of the invention has good biological compatibility, biological degradation property and degradation absorptivity, and can be used for haemostasia material, wound cladding material, organization engineering supporting rack material, the transportation and release of medicine, artificial skin and blood vessel, and postoperation anti blocking material, beauty material and catalyzer carrier, filtering membrane and radiation protection material and so on.

The invention belongs to the field of nanoparticle preparation, in particular to metallic nano cluster / silicon dioxide hollow nuclear shell structured nanoparticles and a one-step controllable preparation method thereof. The used surfactant is a nonionic surfactant, the organic phase is cyclohexane, toluene and other organic hydrocarbons, and a metal saline solution and a metal complexing agent are added to form a reversed micelle system. Meanwhile, the complexed metal saline solution in the reversed micelle system is reduced to obtain metallic nanoparticles and then ammonia water and ammoniawater are added directly in the solution to obtain size and shape controllable hollow silicon dioxide nuclear shell material with metallic nano clusters distributed uniformly on the inner wall of thecavity. The method has the advantages of simple process, easy operation and great yield and can obtain size and shape controllable metallic nano cluster / silicon dioxide hollow nuclear shell structured nanoparticles.

The invention discloses an ultra-hydrophobic conductive macromolecular nanometer fiber, which is characterized by the following: the fiber possesses coaxial nanometer fiber of core case structure; the core is 80-300 nanometer diameter polymerization fiber, whose coaxial case is 80-200 nanometer conductive macromolecular layer of 20-40 nanometer conductive macromolecular grain; the polymerization is polyacrylonitile, ethane polyepoxide, polythene pyrrolidone, polymethyl methacrylate, polyvinyl alcohol, cellulose acetate, polycarbonate; the conductive macromolecular is polyaniline, polythiofuran or polypyrrole. The invention utilizes electrostatic spinning and original position chemical oxidized polymeric method, which possesses reversible conversion property of ultra-hydrophobic and ultra-hydrophilic pH value respond in the intelligent microfluid switch, controllable separating technology, electromagnetic screen and sensor.

The invention belongs to the technical field of recovery of lithium-ion batteries and particularly relates to a method for recovering a waste / used lithium iron phosphate positive-pole material by an acid leaching method. The method provided by the invention comprises the following steps: (a) carrying out acid leaching: adding acid into the lithium iron phosphate positive-pole material for acid leaching so as to obtain a suspension, and carrying out filtration, so as to obtain filtrate; (b) carrying out oxidation: adjusting the pH value of the filtrate obtained in the step (a) to be smaller than 1, and adding an oxidant into the filtrate to oxidate ferrous ions in the filtrate into ferric ions, so as to obtain a mixed solution; (c) carrying out separation: adjusting the pH value of the mixed solution obtained in the step (b) to be 1.5 to 4, carrying out a reaction for 1 to 3 hours at the temperature of 60 DEG C to 95 DEG C so as to produce ferric phosphate precipitates, and carrying out filtrating and washing, thereby obtaining lithium-containing filtrate and ferric phosphate. The method provided by the invention is simple in process, continuous in cycle, low in cost and easy to industrialize and is environmentally friendly; the recovery rate of Li, Fe and P reaches 95% or more, subsequent prepared FePO4 is low in impurity content, the particle size is 1 to 6 microns, is uniform and is narrow in distribution, and the morphology is controllable, so that the FePO4 is battery-grade ferric phosphate.

The invention relates to a titanium dioxide / graphene nanocomposite material, a preparation method of the nanocomposite material and application of the nanocomposite material in the field of energy source and cleaning environment. The graphene accounts for 1-25wt% and the balance is titanium dioxide. Morphology of the titanium dioxide is a mesoporous structure or a structure with a dominant high energy surface, and titanium dioxide is scattered uniformly on the surface of graphene. According to the invention, by adopting a titanium source and graphene as initial materials, and water or organic solvents as reaction solvents, the nanocomposite material with titanium dioxide with the mesoporous structure or a titanium dioxide nano sheet with the dominant high energy surface compounded with graphene can be obtained through hydrothermal synthesis or a hydrolysis reaction. The invention can be carried out in an aqueous solution system and the crystallinity of the product is high. The composite material can be applied to a cathode material of a power ion battery, has a higher charge-discharge capacity, is excellent in high current charge and discharge, stable in circulating performance, has very good photocatalytic performance and can be used to light degradation of organic pollutants and water photolysis for preparing hydrogen.

The invention discloses a making method of high-hydrophilicity alumina film, which comprises the following steps: adopting electrochemical polished aluminium foil as anode and platinum piece as cathode; selecting one of sulfuric acid, oxalic acid phosphoric acid with water or poor water (the composite solution of oxalic alcohol and water) as electrolyte solution; using electrochemical oxidizing method to strip aluminium base; removing damping layer; obtaining the product with different shapes and areas.

The invention discloses a lithium ion phosphate positive electrode material of a nanometer core shell structure. The positive electrode material is provided with an inner core active material and a conductive outer shell structure; a conductive agent is an outer shell material; the active material is of an inner core structure; and the structure formula of the inner core active material is LiFe[1-x]MxP[1-y]AyO4, wherein x is greater than or equal to 0, y is less than or equal to 0.1, M is a transition metal element, and A is silicon. Additionally, the invention also discloses a preparation method of the lithium ion phosphate positive electrode material. According to the preparation method in the invention, a porous material is adopted as a synthesis microreactor, and a lithium ion phosphate precursor is loaded and filled in holes, namely, the inner core active precursor reversely wraps a porous precursor so as to form a special nanometer core shell structure, thus the topography granularity of primary granule is controlled; and the lithium ion phosphate positive electrode material of the nanometer core shell structure is prepared by adopting a liquid phase mixed material and solid phase sintering technology. According to the invention, on the premise that the electrical performance of the positive electrode material is not influenced, a nanometer core shell structured active substance with uniform and controllable topography and granularity is synthesized; and the preparation method disclosed by the invention has lower technology, devices and control costs, which is beneficial to large-scale production.

The invention relates to a hydroxyl oxidize iron-nickel-iron hydrotalcite integrated oxygen evolution electrode applicable to alkaline mediums and a preparation method and application thereof. The electrode is applicable to the oxygen evolution reaction in the water-electrolytic hydrogen making process under catalytic alkaline conditions. The hydroxyl oxidize iron-nickel-iron hydrotalcite integrated oxygen evolution electrode and the preparation method and application thereof have the advantages as follows: the nickel-iron hydroxide integrated electrode is shape-controlled, the preparation process is simple and under mild conditions, and the electrode can be used for a water electrolytic tank for hydrogen production from water splitting under external bias potentials; the prepared hydroxyloxidize iron-nickel-iron hydrotalcite integrated oxygen evolution electrode further has a better performance when being used in an alkaline solid polymer electrolyte (AEM) water electrolytic tank; and besides, an extensive utilization value in achieved in regenerative fuel cells (RFC), photoelectro-catalytic devices and electrolytic hydrogen generators.

The invention discloses application of a nitrogen-doped porous carbon fixed Co@Pt nano-particle composite material, prepared by taking ZIF-67 as a template, as an efficient catalyst for oxygen reduction catalytic reaction of a cathode of a fuel cell. The application has the superiorities that (1) a synthetic method of the catalyst is simple and feasible, the shape of the catalyst is controllable, batch preparation can be realized, and the catalytic performance is very stable; (2) the oxygen reduction catalytic reaction of nitrogen-doped porous carbon fixed cobalt-platinum core-shell nano-particles in the cathode of the fuel cell shows that the nano-particles have good catalytic activity and excellent methanol poisoning resistance stability, and compared with traditional commercial Pt / C, the nano-particles have relatively high take-off potentials and half-wave-peak potentials (nano-particles: 0.99V and 0.87V, and Pt / C: 0.98V and 0.83V); and (3) metal organic frameworks (MOFs) for preparing the catalyst have sequential microcellular structures and relatively large specific surface areas and can be widely applied to the storage and conversion of energy sources. Therefore, a method for simply and directly preparing cheap and efficient cathode oxygen reduction electro-catalyst is provided for the fuel cell and has a wide application prospect.

The invention relates to a method for preparing spherical aluminum-doped nickel lithium carbonate for a lithium ion battery positive electrode material by combining liquid phase oxidation and crystallization controlling. Through controlling of the preparation technique, firstly synthesizing a spherical hydroxyl oxygenized nickel cobalt aluminum precursor with high density, and then calcining at the temperature of 500-800 DEG C for 10-24 hours in a flow oxygen gas atmosphere after mixing the precursor with a lithium source, thus acquire the spherical aluminum-doped nickel lithium carbonate with high density. The synthesized aluminum-doped nickel lithium carbonate is in a single spherical shape, has good stacking density, and can be used for improving the volume ratio capacity of a battery.The aluminum-doped nickel lithium carbonate prepared by the method in the invention has the advantages of high specific capacity and good loop stability. The method provided by the invention has the advantages of simple technique, low cost, less pollution, good product performance and suitability for industrialized production.

A process for preparing nano-zinc oxide includes such steps as dissolving soluble Zn salt and urea in water, microwave radiating while reacting by homogenizing-depositing method to obtain the deposit of alkaline zinc carbonate, vacuum drying, ball grinding, calcining to obtain the crystal grains of nano-zinc oxide, mixing with surface modifier, organic solvent and disperser, ball grinding, and microwave radiating which surface modifying.

The invention discloses a method for producing a Ni-Co-Mn ternary hydroxide, and relates to a continuous synthesis method for a Ni-Co-Mn ternary hydroxide for a lithium ion battery. The method is characterized by comprising the following steps in a production process: first, adding a sodium hydroxide solution and an ammonia water solution into a Ni-Co-Mn metal salt solution, controlling the pH value of a reaction system to be 10.0-12.0, and carrying out a crystal nucleus creating reaction till the granularity of a created crystal nucleus reaches 3-5 [mu]m, so as to obtain a mixed solution containing the crystal nucleus; then, converging the mixed solution containing the crystal nucleus, the Ni-Co-Mn metal salt solution, the sodium hydroxide solution and the ammonia water solution, controlling the pH value of a system to be 9.5-11.5, carrying out a crystal nucleus growth reaction, and carrying out aging, filtration, washing and drying to obtain the Ni-Co-Mn ternary hydroxide. The Ni-Co-Mn ternary hydroxide produced according to the method is stable in product performance, narrow in granularity distribution, less in micro powder, and controllable in morphology.

The invention discloses a drop array chip which comprises a substrate. The substrate is provided with hydrophilic areas and hydrophobic areas, and the hydrophilic areas and the hydrophobic areas are alternately arranged to form a hydrophilic-hydrophobic array. The invention further discloses a preparation method of the drop array chip. According to the drop array chip, a large number of array type drop structures with uniform and controllable morphologies can be precisely and efficiently generated through the hydrophilic-hydrophobic property of the surface of the drop array chip, a foundation is provided for complex biochemical application based on drops, and meanwhile the advantages of being low in cost and capable of being reused are achieved.

The invention discloses a preparation method of high-purity superfine spherical cobalt carbonate, and belongs to the field of preparation of metal powder materials. The preparation method is as follows: metal cobalt is used as a raw material to prepare a cobalt salt solution, a complexing agent is used for prepare a complexed cobalt salt solution from the cobalt salt solution, a mixture of an ammonium salt and urea is prepared in to a precipitant solution, a dispersant is added into the precipitant solution, the complexed cobalt salt solution and the precipitant are added agent according to a certain volume ratio by a parallel flow feeding method into a reactor for reaction, the reaction temperature is controlled at 50-80 DEG C, the pH value is controlled to 7.8-8.3, and the stirring speed is 60-200rpm, and finally the superfine spherical cobalt carbonate is obtained by washing, filtering and drying of prepared cobalt carbonate. The preparation method has the advantages of simple production process, easy control, short production cycle, high efficiency and continuous production, a prepared cobalt carbonate product has the advantages of good mobility, uniform particle size distribution, spherical microtopography, high chemical purity and good chemical properties.

A cross linking maleic anhydride-vinyl acetate copolymer preparation method belongs to the field of copolymers. At present, the research on maleic anhydride-vinyl acetate copolymers mostly focuses on the polymerization research of linear polymers. The invention introduces a monomer, cross linking agents and initiators into medium to dissolve under the condition of nitrogen protection, and reacts for 2 to 24 hours under the temperature of 60 DEG C to 90 DEG C; the monomer is maleic anhydride Man and styrene St, the mol ratio is 1:1, and the mass concentration in the polymerization system is 5 percent to 45 percent; the initiators are organic peroxides or azo compounds, and are 0.05 percent to 1 percent of the total mass of the monomers; the cross linking agents are polyfunctionality alkene organic compounds, and are 0.08 percent to 8.8 percent of the total mass of the reactions system, and the rest is the alkyl ester of medium organic acid. The invention does not use surface active agents or stabilizers, can realize the adjustment and control of crosslinking polymer particle size, appearance and chemical physical properties through the adjustment of the addition amount of the cross linking agents.

The invention relates to a method for preparing series of high-purity silver nanometer materials. The method comprises the following steps: using a halogen-containing metal salt adjuvant to treat polyalcohol, a macromolecule surface active agent, the halogen-containing metal salt adjuvant and salts of silver ions in three steps, and then preparing the nanometer materials by performing a hybrid reaction at a high temperature. The nanometer materials prepared by the using the method have the advantages of uniform appearance, high purity, excellent monodispersity, lower cost, and simple reaction device. By using the method, the appearance is controllable, the size controlling scope is wide, and the large-scale synthesis of silver nanometer materials can be realized. The method has an industrialization prospect.

The invention discloses a preparation method of a tin sulfide material. A solvothermal method is adopted, dehydrate-stannous chloride is used as a tin source, the morphology and particle size of the synthetic material are controlled by controlling a sulfur source, the reaction temperature, reaction time, the solvent variety and the surfactant variety, and the SnS photocatalytic material with controllable morphology and high quality is prepared. The method is simple in preparation and easy to carry out, the yield is high, consumed time is short, cost is low, reaction conditions are mild, good development prospects are achieved, industrial production is easy to achieve, and the prepared material has high photocatalytic activity and has good industrial application prospects when serving as the photocatalytic material.

The invention discloses a preparation method of a silicon composite anode material for lithium ion batteries and the silicon composite anode material is composed of nc-Si / packing carbon / cracking carbon. Packing carbon powder is adopted as scattered matrix, Li-Si alloy powder is adopted as a reducing agent and a liquid silicon halide or a liquid silane halide is chemically deoxidized by the high-energy ball milling; afterwards, heat treatment and solvent washing are conducted over the deoxidized silicon halide or silane halide under the shielding gas so as to obtain an nc-Si / packing carbon complex, wherein the nc-Si is nanometer porous silicon and nanometer silicon fiber. The nc-Si / packing carbon complex passes through the high-molecular carbon source cladding and heat treatment under the shielding gas to obtain an nc-Si / packing carbon / cracking carbon composite anode material. A charge-discharge test of constant current is conducted at a current density of 0.1 mA / mg to 0.3 mA / mg; the coulombic efficiency of the first circulation of the silicon composite anode material reaches up to 70 percent to 80 percent; and after 30 circulations, the reversible capacity reaches 680 mAh / g and the capacity retention rate reaches more than 95 percent.

The invention discloses an in-situ synthesis method for a nano tin dioxide / carbon nano tube composite material, which mainly uses an inorganic tin salt, a carbon nano tube and an alkali source as raw materials. The experimental process mainly comprises the steps of precursor preparation, hydrothermal reaction, precipitate washing and drying and the like. The in-situ synthesis method for the nano tin dioxide / carbon nano tube composite material has the advantages that: a hydrothermal method is adopted to realize the in-situ deposition and the growth of the nano tin dioxide on the surface of the carbon nano tube; the obtained SnO2 nano particles have small and uniform particle size (less than 10nm), are well-crystallized, are uniformly coated on the surface of the carbon nano tube, and are tightly combined with the carbon nano tube; the composite material has potential application prospect in the aspects of a gas sensor material, an anode material of a lithium ion battery and the like. The method has no addition of any surface active agent, has simple and easily-obtained materials, simple process without pollution, short preparation period, mild reaction condition and low cost, and is suitable for large-scale production, so the method is an environment-friendly synthesis method.

The invention provides a preparation method for a molecular imprinting material and the molecular imprinting material prepared through the preparation method. The preparation method comprises the steps that silicon oxide is coated on the surfaces of magnetic ferroferric oxide nanometer particles, the magnetic ferroferric oxide nanometer particles are modified with gamma-(methacryloyl chloride) amino propyl trimethoxy silane to obtain magnetic ferroferric oxide nanometer particles with propenyl on the surfaces, the magnetic ferroferric oxide nanometer particles with the propenyl on the surfaces serve as carriers, estrogen receptors are simulated, functional monomers are optimized, a surface imprinting technology is adopted, and then the molecular imprinting material which can simultaneously identify seven kinds of environmental endocrine disrupting chemicals is prepared. According to the preparation method, the easy separation of a magnetic nanometer material, the good water solubility of a silicon oxide nanometer material, the specific recognition ability of molecular imprinting polymers and the surface imprinting technology are mutually combined, the preparation technology is simple, the conditions are mild, the prepared molecular imprinting material is large in adsorption capacity, fast to respond, high in magnetism, good in chemical stability and high in repeating utilization rate, and the problems that at present, multiple trace, steroid and phenol environmental endocrine disrupting chemicals are difficult to simultaneously identify, separate and enrich are solved.

A copolymerization method of phenylethene / maleic anhydride belongs to polymer preparation technical field, for resolving the defect caused by stabilizer in traditional disperse polymerization system, which comprises under nitrogen gas protection, dissolving monomer Man and St, inducer organic hyperoxide or azocompound of suitable ratio in organic acid alkyl ester, the mixture of aromatics and organic acid alkyl ester or the mixture of ketone and alkane to react for 1 / 4-12h at 60-90 DEG C to obtain the disperse system of polymer microballoon, wherein the average particle diameter of microballoon in the disperse system is 90-1715mm, the disperse factor is 1.04-1.004 and the number average molecular weight is 80000-300000g / mol. The invention has the advantages of eliminated stabilizer, simple process, low cost, clean polymer microballoon or particle surface, controllable particle diameter, controllable shape and narrow granularity distribution.

The invention provides a preparing method of a multielement nanometer composite strengthening thermal-resisting aluminum matrix composite. The surface of nanocarbon is coated with a metal ion precursor in advance, the nanocarbon is evenly scattered in aluminum powder, the precursor is converted into oxide through thermal treatment, reactive sintering and densifying treatment are carried out on the obtained composite powder, and the multielement nanometer strengthening aluminum matrix composite is obtained. The nanocarbon has the high specific surface area, the feature size of the nanocarbon is far larger than that of the nanometer oxide, and therefore a proper amount of nanometer oxide can be loaded and evenly led into the aluminum powder, metallic oxide, carbide, an intermetallic compound and other multielement nanometer strengthening phases are generated through the in-situ reaction, and the tissue stability and the thermal resistance of the aluminum matrix composite are improved coordinately. The method achieves the purposes of even leading of high-volume-content multielement nanometer strengthening phases and the space occupation control, and the conventional powder metallurgy technology can be adopted for preparing the multielement nanometer composite strengthening thermal-resisting aluminum matrix composite.

The invention discloses a method for preparing nano manganese dioxides with different appearances by adjusting the reaction time only under exactly same other conditions. The method comprises the following steps of adding potassium permanganate into deionized water, and stirring to form a uniform solution in which the concentration of potassium permanganate is 0.3mol / L; then adding manganese sulfate, wherein the mass ratio of potassium permanganate to manganese sulfate is 5:2; then transferring the solution into a high-temperature high-pressure reaction kettle of which the inner container is a polytetrafluoroethylene inner container; reacting for 1-18 hours at 140 DEG C; cooling, filtering, flushing and finally drying to obtain a target product. In the method disclosed by the invention, the process is simple, the cost is relatively low, the reaction conditions are mild, and the appearance of the crystal form is controllable; the obtained product has stable quality, relatively high catalytic electrochemical activity, wide applicability and the like, and can be widely applied to lithium ion batteries, molecular sieves, catalysts, super capacitors and the like as well as the basic study of related fields.

The invention discloses a nickel hydroxide nanosheet thin-film material as well as a preparation method and application thereof, and belongs to the technical field of nanometer thin-film materials and the technical field of chemical energy storage. Nickel hydroxide nanosheets vertically and sequentially grow on a foam nickel base, wherein the particle size of the nickel hydroxide nanosheets is 0.7-1.5 microns and the thickness is 5-9 nanometers. The preparation method comprises the following steps of: respectively placing foam nickel base sheets in hydrochloric acid, ionized water and ethanol for ultrasonic washing, dissolving soluble nickel salt and hexamine in deionized water to obtain clear solution, obliquely placing the foam nickel sheets in a reaction still, transferring the nickel salt and hexamine solution to the reaction still to carry out hydrothermal reaction, cooling to room temperature by using cooling water after the reaction, taking the foam nickel sheets out from the reaction still for cleaning via water and ethanol, and placing the products in a dryer until the products are dried. The integrated product has large capacitance value (range: 1500-3000F / g or 5-12F / cm<2>), can be well kept under high-current density and has good cycle performance, so that the integrated product is a super capacitor material with huge application prospect.

The present invention provides a doped cobalt carbonate preparation method. The preparation method comprises the following steps: cobalt carbonate is prepared; the cobalt carbonate is added into a metal alkoxide solution to be mixed to obtain the cobalt carbonate wrapped by the metal alkoxide; and the wrapped cobalt carbonate is dried to obtain a doped cobalt carbonate. The present invention also provides the doped cobalt carbonate prepared by the doped cobalt carbonate preparation method, a doped tricobalt tetroxide preparation method, and a doped tricobalt tetroxide prepared by the doped tricobalt tetroxide preparation method. The doped cobalt carbonate preparation method and the doped tricobalt tetroxide preparation method can prepare the doped cobalt carbonate and the doped tricobalt tetroxide which are uniform in particle sizes, evenly coated, and large in particle sizes, respectively.

The invention provides a manganese spinel nano material which comprises CoxMn(3-x)O4, MgMn2O4 and Mn3O4 nano particles as well as ZnMn2O4 hollow nano spheres, hollow micron spheres or nano pieces. The preparation method is as follows: MnO2 is reduced through a reducing agent at room temperature so as to prepare the manganese spinel nano material. The material can form a three-electrode system used for testing the redox property of the material, namely, in the three-electrode system, nano material is used as a working electrode, a Pt sheet is used as a counter electrode, saturated potassium chloride Ag / AgCl is used as a reference electrode and KOH solution is used as electrolyte. The invention has the advantages that the reaction process is carried out at room temperature, and energy source consumption is less; the nano material has a big specific surface area, and is capable of increasing the contact of active substance with oxygen and electrolyte; and the nano material as an electro-catalyst has high electro-catalysis efficiency, and has important value and actual significance in the fields of spinel oxide nano material preparation, electro-catalysis of metal air batteries and fuel cell and the like.

The invention relates to a method for manufacturing series silver nano-sheets in a batch. The method includes dividing polyhydric alcohol, dimethyl formamide, high-polymer surfactant, metal salt adjuvant containing halogen and metal silver salt into three batches to be treated by the aid of the metal salt adjuvant containing the halogen; then uniformly mixing the materials; and obtaining the series silver nano-sheets by means of heating reaction. The silver nano-sheets are uniform in shape, high in purity, fine in monodispersity and low in cost, a reaction device is simple, large-scale preparation of the silver nano-sheets can be realized, and the method has an industrial prospect.

The invention discloses highly dispersed sliver powder and conductive silver paste for film batteries. The highly dispersed sliver powder comprises polymer microspheres and nano-sliver coatings on the surfaces of the polymer microspheres. The polymer microspheres are made from methacrylic resin, photoinitiator 2, 4, 6-trimethylbenzoyl-diphenylphosphine oxide, and polyvinyl alcohol by ultraviolet irradiation. The conductive silver paste for film batteries is formed by well mixing the highly dispersed sliver powder with glass binder and organic solvent. The highly dispersed sliver powder has the advantages that the polymer microspheres are predictable and controllable in morphology and reasonable in size distribution by increasing or decreasing the time of UV (ultraviolet irradiation), the nano-silver powder synthetized in situ can be evenly and compactly coated on the surfaces of the polymer microspheres, the consumption of noble metal, the sliver powder, can be decreased, production cost is lowered, dispersibility and stability of the nano-sliver powder are also increased greatly, and conductivity of the sliver paste is further increased.

The invention relates to a preparation method of graphene aerogel and graphene-carbon nanotube aerogel. According to the method, graphene oxide or a mixture of graphene oxide and carbon nanotube is subjected to drying treatment; graphene oxide is reduced through a magnesium thermal reaction; the material is soaked in an acidic water solution; and impurities are removed, and the material is dried, such that graphene aerogel or graphene-carbon nanotube aerogel is obtained. Compared with prior arts, the method provided by the invention has the advantages of simple process, and is green and environment-friendly. Magnesium powder is adopted as a reducing agent. Compared to reducing agents such as hydrazine hydrate, sodium borohydride, formaldehyde, carbohydrate compounds, ascorbic acid and hydroiodic acid, magnesium powder has higher reducibility, such that the graphene aerogel or graphene-carbon nanotube aerogel with high carbon-oxygen ratio can be prepared. The electrical conductivity of the graphene aerogel or graphene-carbon nanotube aerogel can reach 10<4>s / cm. The graphene aerogel or graphene-carbon nanotube aerogel has large specific surface area, and is non-toxic and harmless. The graphene aerogel or graphene-carbon nanotube aerogel can be widely applied.