5752 results about "Metal salts" patented technology

An integrated carbon honeycomb structure material and its preparation method are disclosed, belonging to the field of carbon materials technology. Based on a co-sacrificial template low-temperature pyrolysis strategy, the target material can be obtained through three main steps: preparation of a metal salt-colloidal microsphere template precursor, precursor pressing and molding, and subsequent calcination and carbonization. This technology has the characteristics and advantages of simple preparation process, regular and controllable macroscopic structure of the sample (such as shape, area, and thickness), rich and tunable chemical composition, and three-dimensional interconnection of graphene carbon matrix. It has great application potential in many fields such as electrochemical energy storage, catalysis, gas separation, adsorption, and electromagnetic shielding.

A long-term fire retarding biochemical liquid composition including: a dispersing agent realized in the form of a major amount of water, for dispersing alkali metal ions dissolved in the water; a major amount of a first fire retarding agent realized in the form of a primary alkali metal salt of a nonpolymeric saturated carboxylic acid, for example, tripotassium citrate, for providing metal potassium ions dispersed in the water when the at least one alkali metal salt is dissolved in the water to form a mixed retardant solution; a minor amount of a second fire retarding agent realized in the form of a secondary alkali metal salt of a nonpolymeric saturated carboxylic acid, for example, potassium, sodium, calcium and / or magnesium benzoate, for providing benzoate ions dispersed in the water when the secondary alkali metal salt is dissolved in the mixed retardant solution, for functioning as a secondary fire retardant agent.

The invention discloses a phosphonic acid-based metal organic framework solid electrolyte as well as a preparation method and application thereof, and belongs to the technical field of solid electrolyte materials. The method comprises the following steps: mixing a metal salt, an organic phosphonic acid ligand and an organic solvent, carrying out a coordination reaction, and treating to obtain MOF powder; heating and activating the MOF powder to obtain activated MOF powder; the method comprises the following steps: mechanically grinding lithium salt and MOF powder to form a mixture, heating to enable the molten lithium salt to permeate and fill MOF channels, and cooling to obtain solid electrolyte powder. The ionic conductivity of the solid electrolyte at 30 DEG C reaches 1.01 * 10 <-4 > S cm <-1 >, and the solid electrolyte is kept stable in a 4.4 V high-voltage window. The symmetrical battery based on the phosphonic acid-based MOF solid electrolyte can stably operate, and shows excellent compatibility and stability of the electrolyte and a lithium metal negative electrode. The method has the advantages of simple operation, cheap and easily available components, and is expected to be suitable for large-scale preparation.

The invention discloses a p-methyl benzyl chloride production process and a production system thereof, p-xylene side chains and chlorine are subjected to a gas phase substitution reaction under micro negative pressure and visible light catalysis to generate crude methyl benzyl chloride and hydrogen chloride, and 99.0% methyl benzyl chloride, a small amount of benzyl dichloride and 31% hydrochloric acid are respectively generated through rectification and absorption; the device consists of four working sections of chlorination, rectification, hydrochloric acid absorption and distillation. According to the method, the defects in the prior art are overcome, on one hand, chlorine is introduced, and an aromatic ring chlorination reaction is carried out under visible light catalysis; on one hand, a supported catalyst filler is arranged at the bottom of a chlorination tower, and a zeolite molecular sieve modified by long-chain alkylsilane and supported by metal salt is used as a catalyst to catalyze chloromethylation reaction, on the other hand, the hydrophobicity of the modified catalyst is obviously enhanced, and meanwhile, the density of acidic sites is not reduced; the contact opportunity of the catalyst and a reaction substrate is greatly increased, and the catalytic efficiency of the catalyst is improved.

The invention belongs to the technical field of catalysts, and particularly relates to a supported catalyst as well as a preparation method and application thereof. The preparation method of the supported catalyst provided by the invention comprises the following steps: mixing soluble transition metal salt, a carrier, an alkaline aqueous solution and water, and dipping to obtain a primary catalyst; the soluble transition metal salt comprises transition metal oxalate, transition metal formate or transition metal citrate; and carrying out microwave roasting on the primary catalyst to obtain the supported catalyst. According to the method, the transition metal salt is used as a roasting precursor, the transition metal is subjected to in-situ reduction in the reducing atmosphere generated during thermal decomposition of the transition metal salt in the roasting process, roasting and reduction are completed through microwave roasting one-step heating, the preparation steps are simplified, and meanwhile energy consumption is reduced. The supported catalyst is used in a catalytic condensation coupling hydrogen transfer reaction, has high conversion rate and coupling product selectivity, and can stably operate for a long time.

The invention discloses a preparation method and application of an amorphous nickel-cobalt-iron phosphate anode catalyst, and belongs to the technical field of alkaline water electrolysis hydrogen production, the preparation method comprises the following steps: (1) dissolving transition metal salt in a solvent, and stirring to obtain a metal salt solution; (2) dissolving phosphate in a solvent, and stirring to obtain a phosphate solution; and (3) adding the phosphate solution into the metal salt solution for reaction, washing with deionized water and ethanol, centrifugally separating, and drying to obtain the amorphous nickel-cobalt-iron phosphate anode catalyst. According to the preparation method and application of the amorphous nickel-cobalt-iron phosphate anode catalyst, process safety improvement and environmental friendliness optimization are achieved through an all-water-phase green synthesis system, the obtained catalyst shows excellent performance in an AEM electrolytic cell, the cell voltage is only 1.87 V under the current density of 2 A / cm, and the method has remarkable industrial application prospects.

The invention belongs to the technical field of energy storage materials, and particularly relates to a high-entropy oxide Fe0. 2Co0. 2Ni0. 2Cu0. 2Zn0. 2O and an ultrafast synthesis method and application thereof. According to the preparation method, ferroferric oxide, cobalt oxide, nickel oxide, copper oxide and zinc oxide with equal molar ratio are adopted as direct synthesis raw materials, toxic gases such as chlorine and nitrogen dioxide generated in the synthesis process of a metal salt precursor are avoided, and the uniformly distributed single-phase high-entropy oxide is synthesized in an ultrafast manner within 10 seconds by using a Joule heating technology; the synthesized high-entropy oxide is used as a lithium ion battery negative electrode material, and shows more excellent electrochemical performance and cycling stability compared with other high-entropy oxides prepared from transition metals with different proportions; in the preparation process, extra additives are not needed, operation is easy, the synthesis speed is high, the yield is high, element distribution is uniform, and the method has the advantages of being low in cost, high in efficiency and free of pollution and has the industrialization prospect.

The present disclosure is directed to a processing solution composition comprising a metal salt, an acid, a solvent, and a non-metal reductant. The present disclosure is also directed to a method of impregnating a porous material by covering or coating the porous material with a processing solution comprising a metal salt, an acid, a solvent, and a non-metal reductant.

The invention provides anti-ionizing radiation powder with a core-shell heterogeneous gradient structure and a preparation method and application of the anti-ionizing radiation powder, and belongs to the field of radiation protection.The preparation method of the anti-ionizing radiation powder with the core-shell heterogeneous gradient structure comprises the following steps that high-atomic-number metal salt is added into deionized water, aging, washing, drying and primary calcination are conducted in sequence, and the anti-ionizing radiation powder with the core-shell heterogeneous gradient structure is obtained; a core layer is obtained; the core layer and low-atomic-number metal salt are added into deionized water, aging, washing, drying and primary calcination are sequentially conducted, and preliminary wrapping powder with the high-atomic-number metal core layer wrapped by low-atomic-number metal is obtained; and adding the preliminarily wrapped powder and rare earth salt into deionized water, and sequentially performing aging, washing, drying, primary calcining, secondary calcining, airflow crushing and air rotation purging to obtain the anti-ionizing radiation powder with the core-shell heterogeneous gradient structure. Through cooperation of the core-shell heterostructure, the high-atomic-number oxide, the low-atomic-number oxide and the multi-element rare earth element, the shielding performance of the material is remarkably improved.

The invention belongs to the field of photocatalytic materials, and particularly relates to a high-entropy sulfide and a preparation method and application thereof. The high-entropy sulfide is granular, the molecular general formula is (MnaFebCocCudZe) xS, x is equal to 1, and the atomic ratio of Mn to Fe to Co to Cu to Zn is a: b: c: d: e of (1-2): (1-2): (1-2): (1-2): (1-2): (1-2): (1-2). The preparation method comprises the following steps: S1, dissolving metal salt in a mixed solvent of isopropanol and glycerol according to the atomic ratio of metal elements, and carrying out solvothermal reaction to obtain a precursor; and S2, dispersing the precursor in ethanol, adding thioacetamide as a sulfur source, and carrying out solvothermal reaction to obtain the high-entropy sulfide. The high-entropy sulfide disclosed by the invention is used as a photocatalytic material and shows excellent photocatalytic performance.

The invention discloses a high-entropy nanoparticle catalytic material with a metal atom shell structure and a preparation method of the high-entropy nanoparticle catalytic material, and belongs to the technical field of preparation of catalytic materials. The preparation method comprises the following steps: dispersing a metal salt and a nanofiber precursor in an organic solvent, and carrying out electrostatic spinning to obtain a nanofiber membrane; and then calcining and pre-oxidizing the nanofiber membrane, and then carbonizing and calcining to obtain the nanofiber membrane. Wherein the selection principle of the metal salt is as follows: (n-1)-(n-2) metals are selected as an alloy substrate, and the sum of the mixing enthalpy of elements of the alloy substrate is not greater than-5kJ mol <-1 >; one or two metal elements serve as a precipitated phase, and the sum of the mixing enthalpy of the metal elements of the precipitated phase and the elements of the alloy substrate is larger than 20 kJ mol <-1 >; the high-entropy nanoparticle catalytic material obtained by the method shows relatively high catalytic activity and stability, and the method has wide universality.

The invention discloses a bimetallic composite catalyst of copper and rare earth, a preparation method of the bimetallic composite catalyst and application of the bimetallic composite catalyst in electrochemical reduction of carbon dioxide. The preparation method of the bimetallic composite catalyst comprises the following steps: mixing copper salt and rare earth metal salt in water, adding ammonium carbonate and inorganic alkali into the mixture, stirring and reacting, and centrifuging, washing and drying the mixed solution to obtain a catalyst precursor; calcining the catalyst precursor to obtain the bimetallic composite catalyst, the Cu and rare earth bimetallic compound catalyst has the advantages of high current density, high selectivity, good system stability and long service life when being used for electrically reducing CO2. The catalyst has rich active sites, has a large surface area, can be fully contacted with an electrolyte and CO2, and can overcome the limitation of substance transfer. Selective output of methane or multi-carbon products is efficiently achieved by regulating and controlling the molar ratio of copper to rare earth elements, the partial current density of methane and the multi-carbon products reaches the industrialization level, and the catalytic effect is excellent.

The invention discloses a metal-doped carbon quantum dot as well as preparation and application of the metal-doped carbon quantum dot in a nano antibacterial agent, citric acid, urea and tea polyphenol are taken as precursors, metal salt is added, carbon dot synthesis and metal ion doping are synchronously completed in one step through a hydrothermal method, and the metal-doped carbon quantum dot is prepared; the surfaces of the metal-doped carbon quantum dots are negatively charged, and the metal-doped carbon quantum dots have peroxidase-like activity and catalase-like activity at the same time; the metal ions adopt any one of Fe < 3 + >, Cu < 2 + > and Ce < 3 + >; the metal-doped carbon quantum dots are in a sphere-like shape. The metal-doped carbon quantum dots prepared by the preparation method disclosed by the invention have peroxidase-like activity and catalase-like activity at the same time through precise doping of metal ions, and the two activities have a synergistic effect in an oral periodontitis microenvironment, so that a good antibacterial effect is achieved.

Articles for reducing the risk of infection, bearing, or containing an antimicrobial composition containing a solid-phase peroxyxcarboxylic acid metal salt are provided. Methods of reducing the risk of infection using the antimicrobial composition are also provided.

The invention relates to the technical field of flocculants, in particular to a composite flocculant containing a cationic etherifying agent and a preparation method of the composite flocculant, and the composite flocculant is prepared from the following raw materials in parts by weight: 15-20 parts of carboxymethyl guar gum, 12-15 parts of cationic konjac glucomannan, 1.2-1.5 parts of the cationic etherifying agent, 1.8-2.2 parts of a magnetic polysilicate metal salt flocculant and 0.2-0.3 part of a preservative. According to the present invention, by compounding the flocculant, the flocculated floc has magnetism and can be recovered and repeatedly utilized, and the photoresponse azobenzene structure is grafted in the cationic konjac glucomannan, such that the controllable pollutant aggregation and separation can be achieved, and the good flocculation performance can be maintained after the composite flocculant is repeatedly recovered and repeatedly utilized.

The invention provides a polyanionic precursor, a sodium-ion battery positive electrode material, a preparation method of the sodium-ion battery positive electrode material, a sodium-ion battery and electric equipment, and relates to the field of sodium-ion batteries. The polyanionic precursor contains a substance of which the chemical general formula is NaqMm + nM'wPxOy.zH2O. The preparation method of the polyanionic precursor comprises the following steps: mixing a metal salt containing M < 2 + > and a first phosphorus source containing pyrophosphate to obtain a mixed solution, and reacting to obtain a mixed solution of pyrophosphate containing divalent metal M; and adding an oxidizing agent and a second phosphorus source for reaction, carrying out solid-liquid separation, and drying the separated solid to obtain the polyanionic precursor. The polyanionic precursor is high in tap density, and the prepared sodium ion battery positive electrode material is high in purity and excellent in electrochemical performance. The polyanionic precursor provided by the invention contains a small amount of insoluble Na, so that a sodium source can be saved when a positive electrode material is prepared.

The invention discloses deep eutectic gel polymer electrolyte as well as preparation and application thereof, belongs to the technical field of battery electrolyte, solves the problems of low thermal stability, low ionic conductivity and poor mechanical property in the prior art, and comprises a bimetallic salt-eutectic solvent and a polymer chain which are dynamically crosslinked and constructed, the bimetallic salt-eutectic solvent comprises lithium ions, heterogeneous metal salt and Lewis base, and the polymer chain is formed by free radical polymerization, atom transfer radical polymerization (ATRP) or reversible addition-fragmentation chain transfer radical polymerization (RAFT). According to the invention, the deep eutectic solvent is introduced as a reaction solution, so that the organic gel monomer is subjected to photopolymerization or thermal polymerization in the solution, the elongation at break can reach more than 500%, the organic gel has excellent mechanical stretchability, a polymer network is formed by utilizing a long-chain molecular formula of a polymer chain, the deep eutectic solution is wrapped in the polymer network, and the organic gel has excellent thermal stability; and the good ionic conductivity of the electrolyte is ensured.

The invention discloses a special oiling agent for paddle-free DTY (Draw Textured Yarn) as well as a preparation method and application of the special oiling agent. The oiling agent comprises the following components in percentage by mass: 30-50% of a lubricant, 10-20% of an antistatic agent, 15-25% of a bundling agent, 1-5% of an antioxidant, 5-10% of an emulsifier and the balance of deionized water. According to the invention, the traditional sizing process is omitted in fiber processing. The oiling agent can significantly improve the fiber performance and reduce the production cost, has excellent environmental protection property, and is suitable for efficient production of synthetic fibers such as terylene, chinlon and the like. After being treated by the oiling agent, the oiling agent forms a compact protective film on the surface of the fiber, has bundling and lubricating functions, does not need additional sizing, can reduce fiber hairiness, improve breaking strength and remarkably improve the antistatic performance, and the oiling agent containing the metal salt multi-effect antistatic agent can remarkably improve the antistatic performance and also can improve the anti-static performance of the fiber. The anti-ultraviolet performance and the antibacterial performance of the fiber can be improved at the same time.

The invention discloses a multi-metal borate nano-particle as well as a preparation method and application thereof. The preparation method comprises the following steps: in the presence of small molecules with alkyl chains, performing high-temperature thermal decomposition on an organic metal compound or a metal salt compound precursor and organic borate in a solvent, and then centrifuging, modifying, performing ultrafiltration, dialyzing and purifying to obtain the multi-metal borate nanoparticles. The preparation method disclosed by the invention has the characteristics of mildness, high efficiency and strong controllability. The multi-metal borate nanoparticles prepared by the preparation method disclosed by the invention have the advantages of monodisperse size, relatively high magnetic property and good biocompatibility. Therefore, the prepared multi-metal borate nanoparticles not only have multi-modal imaging functions such as magnetic resonance imaging, near-infrared two-region imaging, nuclear medicine imaging and magnetic particle imaging, but also can be used for various treatment means such as magnetocaloric therapy and boron neutron capture therapy; potential advantages are realized in biomedical applications such as magnetic targeting tumor treatment and imaging contrast agents, and high practical values are realized.

The present invention discloses a low-temperature conductive adhesive, which is prepared by weight using raw materials including 70-80 parts of silver powder, 20-30 parts of resin matrix, 1-10 parts of curing agent, 0.1-0.5 parts of silane coupling agent, 0.1-0.5 parts of stabilizer, and 0.1-0.5 parts of metal salt. The present invention introduces an organic metal salt into the resin matrix to reduce the contact resistance of the colloid, and after wet heat aging, maintains a lower contact resistance increase rate. The present invention adopts a combination of epoxy resin, acrylate and modified epoxy acrylic resin, and the weight of epoxy resin and acrylate is less than or equal to the weight of modified epoxy acrylic resin, so that low-temperature curing can be achieved. The present invention can achieve 60-80 ° C, 20-40 min curing, and the conductive adhesive elongation at break obtained can reach more than 8%, and before and after wet heat aging, there is a more stable and relatively small contact resistance, which is particularly suitable for the electronic field with high requirements for contact resistance.

The invention relates to cerium dioxide and a preparation method and application thereof, and the preparation method of the sphere-like cerium dioxide comprises the following steps: (1) carrying out first mixing on cerium salt, doped metal salt, a solvent, inorganic acid and organic acid to obtain a first mixture; the doped metal salt comprises praseodymium salt and / or neodymium salt; (2) under a hydrothermal condition, carrying out second mixing on the first mixture, ammonia water and ammonium salt to obtain a second mixture with the pH value of 8-10, and carrying out sol-gel reaction to obtain sphere-like cerium dioxide sol; and (3) carrying out post-treatment on the sphere-like cerium dioxide sol to obtain the sphere-like cerium dioxide. According to the preparation method of the sphere-like cerium dioxide, provided by the invention, a mixing process and a reaction process of cerium salt and specific raw materials are designed, so that the sphere-like cerium dioxide with regular particle shape, good size uniformity and high purity and crystallinity is obtained.

The invention belongs to the field of electrochemistry, and particularly relates to a method for electrochemical lithium extraction of a decommissioned lithium battery assisted by a pseudocapacitor cathode, which comprises the following steps: a) providing an anode electrode and a cathode electrode; the anode electrode is an anode electrode made of a recycled retired lithium battery anode material or an retired lithium battery anode plate; the cathode electrode contains a Prussian blue analogue, the Prussian blue analogue is prepared by mixing citrate, transition metal salt and cyanide in water for reaction, and the transition metal salt is one or more of cobalt salt, ferric salt, copper salt and nickel salt; and b) immersing the anode electrode and the cathode electrode into the electrolyte, and electrifying to carry out electrochemical lithium extraction. According to the method, a pseudocapacitance material with a lithium discharging characteristic is adopted as a cathode to replace a common metal pole plate or a carbon material, a pseudocapacitance reaction with a corrected electrode potential is adopted to replace a hydrogen evolution reaction on the cathode of an existing system, and finally, low-energy-consumption and high-selectivity recovery of lithium is realized.

The invention belongs to the technical field of high-purity gas preparation and catalysis, and discloses a copper-iron double-component composite catalyst for removing trace acetylene and ethylene in petrochemical byproduct hydrogen chloride gas to prepare electronic grade hydrogen chloride gas, and a preparation method of the copper-iron double-component composite catalyst comprises the following steps: immersing activated carbon in hydrochloric acid; washing the activated carbon carrier with deionized water until the pH is neutral, and drying to obtain the pretreated activated carbon carrier; and impregnating the active component on the pretreated active carbon carrier, carrying out ultrasonic-assisted impregnation, standing, and drying, thereby obtaining the product, the active components are Fe metal salt and Cu metal salt. According to the method, trace acetylene and ethylene in the petrochemical byproduct hydrogen chloride gas are catalyzed to react with the hydrogen chloride gas at the same time, so that acetylene and ethylene are removed at the same time, and the acetylene and ethylene removal step in the existing hydrogen chloride purification process is simplified. Compared with a traditional method, the reaction efficiency of preparing the electronic-grade hydrogen chloride gas is remarkably improved.

A bioleaching composition for treating ores or other materials including metals or metal salts is presented, wherein the bioleaching composition includes a biosurfactant and a metal solubilizing agent. The biosurfactant may be a sophorolipid biosurfactant (SLP), and the metal solubilizing agent includes an acid and an oxidizing agent or a microorganism. In a bioleaching process using the bioleaching composition, the metal in the ore may be separated from a solution phase or a non-solution phase. Compositions derived from microorganisms are also provided for the pre-leaching treatment of a metal source, which compositions can be used to reduce impurities in the metal source. The use of the bioleaching composition increases the extraction rate and / or the throughput of the process.

This invention discloses a method for preparing a CuZnAlGa-based layered double hydroxide (TLH)-derived catalyst for methanol production from carbon dioxide-rich syngas. Using Cu, Zn, Al, and Ga metal salts as precursors, Na₂CO₃ and NaOH as precipitants, and a mixed alcohol-water solution as an auxiliary solvent, co-precipitation is performed under controlled temperature and pH to obtain a LDH-like catalyst precursor. After high-temperature calcination and in-situ reduction in a hydrogen atmosphere, a layered framework structure of Cu nanoparticles immobilized by oxides is obtained. The LDH-like structure provides lattice confinement, preventing Cu particle aggregation, and the interaction between Cu and the oxides enhances the catalyst surface's adsorption capacity for CO and CO₂, thereby improving the activity and stability of methanol production from carbon dioxide-rich syngas.

The invention discloses a stress whitening resistant polyamide composite material, which comprises the following components by weight: 74-86 parts of polyamide; 0.1-1 part of rice bran wax metal salt; 5-30 parts of a toughening agent; and 0.3 to 0.8 part of carbon black and 0.1 to 0.5 part of aniline black. The rice bran wax salt is used as a nucleating agent to reduce the grain size of the crystal, the aniline black can improve the tinting power to a crystalline region to reduce light reflection at a stress whitening position, the carbon black can also adjust the tinting power to the crystal and an amorphous region, and under the cooperation of the three, the grain size of the crystal is reduced to be smaller than the wavelength of visible light to realize absorption of visible light. Light reflection caused by tiny gaps generated by separation of the flexibilizer and a polyamide resin matrix after the polyamide composite material is bent under stress is improved, and the defect of stress whitening of the polyamide composite material is remarkably reduced.

The invention relates to the technical field of gas separation membranes, in particular to a gas separation membrane based on a metal organic cage and a preparation method and application of the gas separation membrane based on the metal organic cage, a solution containing metal salt, an organic ligand and an organic solvent is prepared and reacts for 2-160 h at the temperature range of 50-200 DEG C, and a metal organic cage material is obtained; preparing a water-phase dispersion liquid containing a metal organic cage and an organic-phase reaction liquid containing polyacyl chloride or polyaldehyde; placing the organic phase reaction liquid on the surface of a support membrane to obtain a support membrane adsorbing an organic phase monomer; placing the water-phase dispersion liquid on the surface of a support membrane adsorbing an organic-phase monomer to obtain a nascent state separation membrane; the operation is repeated, the organic phase reaction liquid and the water phase dispersion liquid are poured on the surface of the nascent state separation membrane for multiple times, and the gas separation membrane based on the metal organic cage is obtained. The metal organic cage gas separation membrane prepared by the invention has high CO2 permeation rate, relatively high CO2 / N2 and CO2 / H2 separation factors and good long-term operation stability.

Adhesive compositions including a multivalent metal salt, an multidentate acidic organic compound, and an aqueous medium are disclosed. The multivalent metal salt and multidentate acidic organic compound can include, as a mixture, a carbonate salt and / or carbonic acid. The aqueous medium can include pH adjusting agent such as sodium hydroxide. The adhesive composition, upon curing, can have a porosity of 10-50%. The adhesive composition, upon curing, can include a plurality of pores. The adhesive composition can be porous, and upon curing can have a plurality of pores having a pore size of between 20 μm to 200 μm. Methods of producing the adhesive composition are disclosed. Methods of using the adhesive composition are further disclosed.

The invention belongs to the field of flame-retardant finishing of textiles, and discloses a phytic acid-based flame retardant and a preparation method of a flame-retardant cotton fabric. Natural phytic acid, polyethylene glycol, melamine and metal salt are used as main raw materials, the environment-friendly characteristic of a biomass material is combined, an efficient and environment-friendly flame retardant is prepared, the prepared flame retardant is arranged on a cotton fabric through a traditional impregnation method, and the flame retardance and smoke suppression performance of the arranged cotton fabric are greatly improved. The method not only has a good flame retardant effect, but also avoids potential hazards of a traditional flame retardant to the environment and human health, and has a wide application prospect. The flame-retardant cotton fabric can be widely applied to the fields of household textiles, protective clothing, fire-fighting equipment and the like, and has remarkable economic benefits and social benefits. The invention not only provides an efficient and environment-friendly flame retardant preparation method, but also opens up a new way for application of biomass materials in the field of flame retardance, and has important scientific significance and practical value.

The invention provides a polyimide multilayer composite membrane material as well as a preparation method and application thereof, and belongs to the technical field of gas separation. According to the method, through collaborative design of a functional support layer, a gradient MOF layer and an ultrathin selection layer structure, the problems of support layer pore seepage, MOF agglomeration, weak interface bonding and the like in an existing composite membrane material are solved. The preparation method comprises the following steps: firstly, carrying out electrostatic spinning on a polyamide acid glue solution, and synchronously introducing dopamine by adopting a chemical imidization method to prepare a functionalized polyimide fiber membrane containing hydroxyl and amino on the surface, so that the mechanical property of a supporting layer and the MOF anchoring capability are remarkably improved; growing MOF layers with different particle sizes on the surface of the fiber membrane by regulating and controlling the concentration gradient of ligand / metal salt and the reaction time, and passivating through a silane coupling agent after each step of growth so as to avoid heterogeneous nucleation and construct a gradient structure; after the MOF gradient layer is subjected to Ar plasma pretreatment to introduce hydroxyl, the ultrathin polyamide selection layer is formed by utilizing interfacial polymerization of fluorine-containing acyl chloride and a macrocyclic amine monomer, and the ultrathin polyamide selection layer is suitable for gas separation work.