6424 results about "Nanofiber" patented technology

The invention belongs to the technical field of gel materials, and particularly relates to aerogel powder for polyolefin modification and a preparation method and application thereof. The preparation method of the aerogel powder comprises the following steps: (1) preparing aramid nanofiber dispersion liquid; (2) preparing a polypyrrole coated aramid nanofiber dispersion liquid; (3) mixing polyamide acid and the polypyrrole coated aramid nanofiber dispersion liquid, and then carrying out partial imidization and solvent exchange to prepare hydrogel; and (4) carrying out freeze drying, thermal imidization and crushing to obtain the aerogel powder for polyolefin modification. The aerogel powder is a porous solid material formed by forming one-dimensional composite fibers from aramid nanofibers and polypyrrole and combining the one-dimensional composite fibers with polyimide resin. The aerogel powder and polyolefin resin are compounded to obtain the polyolefin resin composite material with high strength and antistatic property, and the polyolefin resin composite material can be widely applied to the fields of pipes, plates, grouting equipment parts, grouting bags and the like.

The invention belongs to the technical field of fiber materials, and particularly relates to a modified aramid nanofiber as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) preparing an aramid nanofiber dispersion liquid; (2) modifying the aramid nanofiber by using POSS; and (3) carrying out in-situ polymerization on polypyrrole on the surface of the aramid nanofiber. POSS (polyhedral oligomeric silsesquioxane) has a relatively large volume exclusion effect, the template effect of long-chain alkyl quaternary ammonium salt can be influenced by scattered adhesion of POSS on the surface of aramid nanofiber, uneven polymerization of pyrrole monomers is caused, and formation of a rough structure on the surface of the fiber is facilitated. According to the invention, the polypyrrole-coated aramid nanofiber with a coarse structure is used as a polyolefin modified material, so that the problem of low interfacial force existing in a common filler is solved, and the polyolefin resin composite material with high strength and antistatic property is obtained and can be widely applied to the fields of pipes, plates, grouting equipment parts, grouting bags and the like.

The invention discloses slurry, a battery diaphragm, a preparation method of the battery diaphragm and a battery, and belongs to the technical field of batteries. The slurry comprises the following components: ceramic particles, carbon nanofibers, a binder I and a solvent I, the ceramic particles comprise ceramic particles I and ceramic particles II; the particle size of the ceramic particles I is 0.55-1 [mu] m, and the particle size of the ceramic particles II is 0.05-0.45 [mu] m. The battery diaphragm comprises a base membrane and a composite coating, the composite coating is attached to at least one surface of the base film; the composite coating is formed by curing the slurry provided by the invention. The battery diaphragm provided by the invention has good thermal stability and mechanical strength, the passing rate of the lithium ion battery in coping with safety tests such as extrusion, puncture and heavy object impact is greatly improved, and meanwhile, the electrochemical performance of the lithium ion battery is also improved.

The invention provides a composite nanofiber membrane applied to detection of a C4F7N gas decomposition component C3F6, a preparation method of the composite nanofiber membrane and a sensing device. The composite nanofiber membrane comprises a polymer nanofiber substrate and a metal organic framework dispersed in the polymer nanofiber substrate, the metal organic framework is MIL-101 (M), and M represents a metal element and comprises at least one of Cr, Cu and lanthanide series metal elements; the surface of the interdigital electrode is coated with the composite nanofiber membrane, and the composite nanofiber membrane serves as a sensing device and is used for detecting C3F6 gas. The sensor disclosed by the embodiment of the invention can generate response within 25s, still has certain sensitivity (which is 3% or above) to 10ppm of C3F6 gas, and meets the requirements on high sensitivity and quick response in detection of a C4F7N gas decomposition product C3F6.

The invention discloses a hydrophobic-hydrophilic Janus water collecting film and an efficient preparation method thereof, and belongs to the field of water collecting materials. An electrostatic spinning process is adopted, and a hydrophobic polymer is accurately deposited on the surface of a hydrophilic substrate in the form of a nanofiber array, so that the Janus composite membrane with an asymmetric wetting gradient structure is successfully constructed. The unique double-sided wettability difference drives the liquid drops to realize directional transmission, and the core mechanism of the liquid drops is derived from capillary force regulation and control caused by interfacial wetting potential energy difference. The Janus membrane shows excellent performance in the aspect of air moisture trapping, the ultra-fast moisture absorption characteristic and the surface regeneration capacity are achieved, and compared with a traditional single-layer hydrophilic membrane, the water collecting efficiency is remarkably improved by 110%. A one-step forming process is adopted for preparation, the diameter of the nanofibers is controllable, complex post-treatment procedures are not needed, and energy consumption required by equipment is low. The high-performance water collecting film has important application value in the fields of atmospheric water taking in arid regions, dehumidification of precise instruments and the like.

The invention belongs to the technical field of composite fiber materials, and relates to a functional thermal management fabric, in particular to a phase change microcapsule doped flexible cooling fiber fabric and a preparation method thereof. The fabric has a controllable double-layer structure and is formed by assembling nanofibers and micro-nanofibers doped with a large number of phase change microcapsules. Wherein the micro-nano fiber layer has relatively high sunlight reflectivity and atmospheric window wave band emissivity, and shows an excellent radiation cooling effect; the microcapsule content of the nanofiber layer doped with a large amount of phase change microcapsules is not less than 10 wt%, and the nanofiber layer has no rupture phenomenon, has high heat storage capacity, not only makes up for the deficiency of radiation cooling capacity, but also effectively slows down temperature fluctuation. The radiation cooling technology and the phase change latent heat technology are combined, so that the long-time temperature control performance of the fabric is realized, and the thermal shock resistance is enhanced. In addition, the fabric also has excellent mechanical property, flexibility, washability, air permeability, moisture penetrability and sunscreen property.

The invention discloses a cement-based aerogel heat preservation and heat insulation coating material for concrete and a spraying construction process of the cement-based aerogel heat preservation and heat insulation coating material, and belongs to the technical field of concrete materials. The coating material is prepared from powder, composite emulsion and water, and the powder is prepared by mixing superfine sand, cement, modified silicon dioxide-carbon nanotube composite aerogel powder, hollow glass beads, nanofibers, graphene nanosheets, an ultraviolet light absorber, a water reducing agent and a defoaming agent. The composite emulsion is composed of an acrylate copolymer emulsion, a polyvinyl acetate-ethylene emulsion, a temperature-sensitive polymer emulsion and a coalescing agent. Based on the multi-stage pore network and multi-component emulsion optimization design and multi-component synergistic effect, the material has good fluidity after being mixed, and has low heat conductivity coefficient, high strength and high toughness after being hardened; the construction technology of high-pressure water flushing and layered spraying is provided, and the method has the advantages of being efficient in construction, stable in quality and the like and can be applied to heat preservation and heat insulation of a concrete structure in a severe environment.

The invention provides research and development of an early warning and self-repairing anticorrosive coating based on nanofibers, and the coating can realize timely self-early warning and self-repairing, so that people can timely discover and maintain a damaged part. A shell solution of the synthesized core-shell nanofiber is mainly prepared from a polymer shell material, a shell material spinning aid and a shell material solvent according to the mass ratio of 1: (01-1): (5-15); the core solution is mainly composed of a core material and a core material solvent, and parameters such as the feeding sequence, the heating temperature range, the stirring speed and the reaction time are optimized. A coaxial spinning mode is adopted in electrostatic spinning, and parameters such as voltage, liquid outflow speed and receiver moving speed in the electrostatic spinning process are optimized. The synthesized fiber structure is complex and interwoven together, so that the internal material has extremely high flowability. The coating is formed by mixing industrial epoxy resin, epoxy resin monomers, a curing agent and a diluent according to the mass ratio of 1: (0.2-1): (0.2-1.5). The coating added with the nanofibers has early warning and self-repairing performance at the same time, early warning of the coating material on corrosion under the coating can be achieved, external intervention is not needed, self-repairing is achieved, and important research significance and application prospects are achieved.

The invention discloses a bionic nanofiber-hydrogel composite biological scaffold as well as a preparation method and application thereof. The bionic nanofiber-hydrogel composite biological scaffold is a composite scaffold for simulating a gray-white matter partition structure of a spinal cord tissue, and comprises bionic nanofibers and a bionic hydrogel material, wherein the bionic nanofibers are arranged in an oriented manner and simulate a white matter ordered structure around the spinal cord, and the bionic hydrogel material is combined with the bionic nanofibers and simulates gray matter in the center of the spinal cord. According to the bionic nanofiber-hydrogel composite biological scaffold, the biological activity of loaded stem cells or adult cells can be improved, the problem that a large number of transplanted exogenous cells die due to unbalanced oxidative stress generated after tissue damage can be solved, and it is guaranteed that the transplanted cells reside in a damaged area and play a role; therefore, the spinal cord microenvironment is improved, proliferation and differentiation of endogenous neural stem cells are promoted, functional recovery after spinal cord injury is finally promoted, and great potential is achieved in spinal cord injury treatment.

The invention relates to the technical field of sewage treatment, in particular to a sewage treatment control process based on dynamic regulation and control of aeration and carbon source addition, which comprises the following steps: acquiring microbial metabolism heat change data in real time; biochemical treatment: monitoring the dielectric constant of a water body and the Reynolds number of sewage flow in real time, and constructing a multi-parameter coupling regulation and control model and dynamically regulating and controlling the aeration rate in combination with microbial metabolism heat change data obtained in the pretreatment step; accurately adding the carbon source according to a calculation result of the carbon source demand prediction model; sewage subjected to biochemical treatment is subjected to ultrafiltration through a nanofiber membrane and then subjected to combined disinfection treatment through ultraviolet rays and ozone, treatment parameters are regulated and controlled in real time according to the membrane flux attenuation trend in the treatment process, and dynamic and accurate control over sewage treatment is achieved. According to the method, the problem of energy consumption waste caused by excessive aeration or low degradation efficiency caused by insufficient aeration in a traditional process is solved, and accurate matching of dissolved oxygen supply and microbial requirements is realized.

The invention relates to a flexible electrochemical pH sensor as well as a preparation method and application thereof. Wherein the flexible electrochemical pH sensor comprises a flexible nanofiber substrate as well as a working electrode and a reference electrode which are arranged on the surface of the flexible nanofiber substrate at an interval, the working electrode comprises a first working part and a first wire part connected with the first working part, and the first working part is provided with a polyaniline sensitive layer. The flexible electrochemical pH sensor has the characteristics of high sensitivity, good flexibility and good air and moisture permeability, can be tightly attached to the surface of skin to monitor the pH value of body fluid, and is high in monitoring accuracy and simple in manufacturing method.

The invention belongs to the technical field of biomedical engineering, and particularly relates to a biological rotator cuff patch with a double-gradient structure and a preparation method of the biological rotator cuff patch. The preparation method comprises the following steps: carrying out electrostatic spinning on a spinning solution, controlling the rotating speed of a receiving roller to increase at a constant speed in the electrostatic spinning process, and obtaining a nanofiber membrane after electrostatic spinning; l-polylactic acid and D-polylactic acid are simultaneously dissolved in the spinning solution; the minimum value of the rotating speed of the receiving roller is 100-500 rpm, and the maximum value of the rotating speed of the receiving roller is 3000-4000 rpm. The finally prepared biological rotator cuff patch with the double-gradient structure presents an orientation degree gradient and a piezoelectric effect gradient at the same time on the thickness scale, and has mechanical supporting capacity and biocompatibility, and bionic healing promotion of the patch with the gradient structure is achieved.

The invention discloses a preparation method of a ceramic membrane with efficient separation and catalysis functions as well as a product prepared by the preparation method and application of the ceramic membrane. The preparation method comprises the following steps: preparing a ceramic membrane support body by taking large-particle-size ceramic particles as a raw material, and preparing a transition layer by taking transition metal oxide nanofibers as a raw material by adopting a dip coating method; small-particle-size ceramic particles are used as raw materials to prepare a separation membrane layer by adopting a dip-coating method, and the ceramic membrane with a sandwich structure is formed through one-step co-firing. The transition layer with high porosity and specific surface area is formed by adopting the transition metal oxide nanofibers, so that the number of catalytic active sites and the permeation flux are improved; small-particle-size ceramic particles are adopted to form a separation membrane layer with uniform pore size distribution and a flat membrane surface, so that the separation efficiency of particulate matters and organic matters in water is improved, the accumulation of the particulate matters and the organic matters on the membrane surface is reduced, and meanwhile, the particulate matters and the organic matters in water are prevented from covering active sites of the catalytic ceramic membrane; therefore, the separation efficiency and the catalytic degradation efficiency of the ceramic membrane are synchronously improved.

The invention relates to the field of physiological status detection, and provides a wearable microfluidic fluorescence sensor based on a Janus membrane for sweat analysis. The sensor comprises a Janus membrane-based micro-fluidic chip and a fluorescent sensing layer which are stacked, the Janus membrane-based micro-fluidic chip comprises a hydrophobic nanofiber membrane, a bottom polydimethylsiloxane layer, a hydrophilic nanofiber membrane and a top polydimethylsiloxane layer which are stacked, and the fluorescent sensing layer comprises three paper chips, the simultaneous fluorescence detection of chloride ions, glucose and pH of sweat is realized. The Janus membrane with the directional water conveying capacity is used as a substrate for preparing a micro-fluidic chip. In one aspect, sweat may be automatically delivered to an analysis zone along a designed path. On the other hand, sweat is transferred from a hydrophobic membrane close to the skin to a hydrophilic membrane, sweat accumulation is effectively avoided, and a comfortable skin microenvironment is promoted. A Janus membrane-based micro-fluidic chip is combined with fluorescence sensing, a micro-fluidic fluorescence sensor based on a Janus membrane is constructed, and simultaneous high-stability and high-accuracy analysis of multiple targets in human sweat is realized.

The invention discloses a composite electrode material for a zinc-bromine flow battery and a preparation method and application thereof, and the preparation method comprises the following steps: S1, uniformly stirring a copper salt, a zinc salt, a sodium salt and distilled water at room temperature, aging in air, and then filtering, washing and drying to obtain a zinc-copper composite salt; s2, adding a polymer into an organic solvent under a stirring condition, and stirring under a water bath condition to obtain a spinning solution; then adding zinc-copper composite salt, stirring and then carrying out ultrasonic dispersion to obtain a composite spinning solution; s3, preparing the composite spinning solution into a precursor nanofiber material by utilizing high-voltage electrostatic spinning; and S4, carrying out pre-oxidation and carbonization treatment on the precursor nanofiber material in an atmosphere furnace, and cleaning and drying the carbonized material to obtain the composite electrode material for the zinc-bromine flow battery. According to the invention, the problems of low surface activity of bromine electrode reaction on an electrode material, unstable electro-catalytic performance, bromine permeation and the like in the zinc-bromine flow battery can be solved.

The invention discloses a phase change energy storage waterborne polyurethane nanofiber membrane and a preparation method thereof. Lignin-based phase change microcapsules are prepared by combining ultraviolet crosslinking with lignin shell packaging, and then the nanofiber membrane containing the phase change microcapsules is prepared through an electrostatic spinning technology. And finally, constructing the waterborne polyurethane phase change fiber membrane with asymmetric wettability through a low-temperature plasma technology. According to the invention, lignin is self-assembled to form nanoparticles, and ultraviolet light induces free radical polymerization to form a polymer film, so that the packaging capability of the phase change material is improved. The phase change microcapsule prepared by the method is high in packaging efficiency and excellent in phase change performance, the preparation process is green and environment-friendly, the technological operation is simple, the temperature of the prepared phase change energy storage waterborne polyurethane nanofiber membrane conforms to the comfortable temperature range of a human body, and the phase change energy storage waterborne polyurethane nanofiber membrane has excellent temperature regulation, waterproof and moisture permeable performance and is suitable for being used in the field of water treatment. Good application prospects are realized in the field of functional textiles with functions of intelligent temperature regulation, water resistance and air permeability and the like.

The present invention is an electrospun web including a carrier substrate and an electrostatically charged nanofiber. The electrospun web has a pressure drop of about 5 mmH2O or less, a percent penetration of about 50% or less, and a clarity of about 80% or more.

The invention provides a slit type bubble electrostatic spinning device assisted by hot air flow. The slit type bubble electrostatic spinning device comprises a hot air flow channel, a slit type metal solution channel, a bubble pipe and an electrostatic generator. The hot air flow channel and the slit type metal solution channel are circular truncated cone-shaped pipelines formed by gradually narrowing inner and outer pipes; the pipe diameter of an inner pipe of the hot air flow channel is the same as that of an outer pipe of the slit type metal solution channel; the slit type metal solution channel penetrates through the inner pipe of the hot air flow channel and is fixedly attached to the inner pipe of the hot air flow channel, the bubble pipe extends and is fixed to the inner pipe of the slit type metal solution channel, and the electrostatic generator is connected with the slit type metal solution guide pipe through a wire. The arrangement of polymer molecular chains in the solution is improved through the slit type metal solution channel, high-speed hot airflow is provided by the circular-truncated-cone-shaped hot airflow channel to upwards support bubbles from the periphery and assist the polymer molecular chains to be evenly distributed in parallel with the surfaces of the bubbles, and the enhanced nanofibers are prepared by improving the internal structure of the nanofibers.

The invention provides a carbon nanotube / polyvinyl alcohol hydrogel and a preparation method and application thereof, and belongs to the technical field of composite materials and flexible electron cross materials. Cellulose nanofibers and multi-walled carbon nanotubes are dispersed in deionized water to obtain dispersion liquid; uniformly mixing a polyvinyl alcohol solution and the dispersion liquid to obtain a mixed solution; carrying out oriented freezing forming on the mixed solution, and then freeze-drying the mixed solution to obtain an aerogel sample; performing hot pressing on the aerogel sample to obtain a thin film material; and swelling and balancing the film material in deionized water to obtain the carbon nanotube / polyvinyl alcohol hydrogel. According to the invention, collaborative optimization of conductive network continuity, interface bonding strength and energy dissipation capability is realized, so that high conductivity, high stress and obdurability are considered, and the material is endowed with multi-dimensional strain sensing capability and signal stability; and a new idea is provided for realizing effective balance between high conductivity and excellent mechanical properties of the hydrogel material.

The invention discloses a flexible multi-mode hydrogel sensing patch as well as a preparation method and application thereof. The flexible multi-mode hydrogel sensing patch is composed of a bottom hydrogel-based bimodal pressure-temperature sensing layer and a top electrostatic spinning nanofiber-based non-contact detection layer. The hydrogel serves as a core base material and has high toughness and water-retaining property, multi-mode sensing of temperature, pressure and non-contact proximity is achieved through different sensing mechanisms, and crosstalk interference does not exist. In a simulated real scene, the feasibility of the multi-mode sensing function of the robot hand is verified by grabbing an object through the robot hand. A plurality of multi-mode sensing patches integrated at different positions of the pillow are used for intelligent sleep monitoring, and a one-dimensional convolutional neural network is used for acquiring and analyzing various human pillow interaction information and time-dependent evolution thereof, so that tracking of head movement and recognition of wrong postures possibly causing poor sleep are realized; and a promising method is provided for sleep monitoring.

The invention discloses a C5F10O mixed gas decomposition component adsorption material as well as a preparation method and application thereof. The adsorption material is a metal organic framework / nanofiber composite membrane which is prepared by uniformly dispersing a metal organic framework material on a nanofiber membrane obtained by an electrostatic spinning technology through a spraying doping method and is used for adsorbing decomposition components of C5F10O mixed gas. According to the adsorption material provided by the invention, through mutual cooperation of the metal organic framework material and the porous nanofiber membrane base material, a formed composite membrane has a larger specific surface area and more metal active sites, adsorption of gas molecules is promoted, permeation and diffusion of the gas molecules are also facilitated, and the adsorption efficiency is improved. Therefore, the gas sensitivity and the adsorption effect of the adsorption material are remarkably improved.

The invention belongs to the field of building decoration materials, and discloses a GRG gypsum composite reinforced material and a preparation method thereof. The high-strength concrete is prepared from the following components in parts by weight: 45 to 65 parts of alpha-semi-hydrated gypsum, 12 to 20 parts of composite reinforced fiber, 0.5 to 2 parts of graphene nanofiber, 2 to 5 parts of nano silica fume, 5 to 10 parts of ethylene-vinyl acetate copolymer latex powder, 1 to 2.5 parts of hydroxypropyl methyl cellulose, 0.1 to 0.8 part of polycarboxylic acid type water reducing agent, 1 to 4 parts of calcium stearate, 3 to 8 parts of vermiculite powder and 28 to 40 parts of deionized water. Aiming at the problems that an existing GRG material is insufficient in mechanical property, low in fireproof grade, poor in thermal performance, poor in durability and the like, a multi-dimensional synergistic enhancement system is constructed by adopting composite reinforced fibers, functional nanofiller and a gradient preparation process, the problems of dispersion and interfacial compatibility of the nanofiller are solved, and the comprehensive performance of the GRG material is improved. The performance breakthrough of high strength, high fire resistance, low heat conduction and long durability is realized.

The invention discloses a self-cleaning waterproof coating and a preparation method thereof, and relates to the technical field of waterproof coatings. Wherein the waterproof coating is prepared from organic silicon modified acrylic resin emulsion, a photocatalyst nano composite material, hydrophobic modified silicon dioxide aerogel powder, a nanofiber reinforced material, a dispersing agent, a coalescing agent, a thickening agent, a defoaming agent and deionized water; through the compatibility design of the core-shell structure photocatalyst and the super-hydrophobic silicon dioxide aerogel, multiple self-cleaning of adsorption, degradation and scouring is achieved, the durability and reliability of self-cleaning are remarkably improved, surface modified nanofibers are adopted as a reinforcing material, a three-dimensional network structure is formed in a coating film, and the self-cleaning performance is improved. And the flexibility of the organic silicon modified acrylic resin is synergistically complemented, so that the tensile strength and the deformation resistance of the coating are improved, the brittleness problem of rigid particles is avoided, and the durability of the coating is remarkably improved.

The invention discloses a lithium ion battery composite diaphragm, a preparation method and a lithium ion battery, and relates to the technical field of lithium ion batteries. The lithium ion battery composite diaphragm comprises a base membrane and a functional coating arranged on the negative electrode side of the base membrane, the functional coating sequentially comprises an ion conducting layer, a thermal barrier layer and a self-repairing layer from the position close to the base film to the position far away from the base film; wherein the base membrane is a polyimide and aramid nanofiber blended electrostatic spinning membrane; the ion conducting layer comprises a compound of a modified fast ion conductor and polyvinylidene fluoride-hexafluoropropylene; the thermal barrier layer comprises a cross-linked network of boron nitride nanosheets and polybenzimidazole; the self-repairing layer comprises polyurethane microspheres loaded with dynamic disulfide bonds. The composite diaphragm provided by the invention can remarkably inhibit a purple area on the surface of a negative electrode, and enhance high-temperature self-protection and interface self-repairing of the lithium ion battery, so that the cycle and safety performance of the lithium ion battery are remarkably improved.

Composites of metal-organic framework particles and bacterial cellulose, methods of making the composites, and methods of using the composites in the hydrolysis of organic compounds are provided. The composites, which are aerogels comprising metal-organic framework particles embedded in a bacterial cellulose nanofiber network, are fabricated using a microbial synthesis strategy in which bacterial cellulose nanofiber is biosynthesized using a cellulose-producing bacteria in a fermentation medium in which metal-organic framework particles are dispersed.

The invention provides an aerogel-based heat-preservation, heat-insulation and waterproof composite coating material for a building outer wall and a preparation method thereof, and belongs to the field of building materials. Through hydrophobic modified silicon dioxide aerogel, a lightweight heat insulation frame is provided, and the waterproofness and compatibility are improved; the mechanical property and the crack resistance are enhanced through the modified potassium titanate nanofibers, and self-adaptive heat insulation is achieved; the thermoelectric effect, the wear resistance and the thermal regulation performance are optimized through plasma treatment and polyaniline coated tungsten carbide nanoparticles; the heat management performance, the crack resistance and the comprehensive heat insulation and waterproof capacity are improved through graphene oxide composite modified boron nitride; the flexibility, the hydrophobicity and the interfacial compatibility are improved through organic silicon modified bisphenol A epoxy resin; and the performance of the coating is optimized through the synergistic effect of the components.

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 PBa reinforced aramid III nanofiber flame-retardant aerogel and a preparation method thereof, and belongs to the field of aerogel preparation. The preparation method comprises the following steps: constructing aramid fiber III nanofibers by a deprotonation method, then preparing aramid fiber III nanofiber gel by protonation, then blending a benzoxazine solution and phosphoric acid, and finally freeze-drying to obtain the flame-retardant aerogel. The prepared flame-retardant aerogel is composed of phosphoric acid catalyzed granular polybenzoxazine (PBa) and a cross-linked aramid fiber III nanofiber skeleton and has a longitudinal stripe pore structure, and the granular PBa with phosphoric acid covers aramid fiber III nanofibers to cooperatively construct a continuous and stable flame-retardant skeleton, so that a multi-stage flame-retardant structure is provided for the flame-retardant aerogel. The flame-retardant aerogel prepared by the invention has good and stable mechanical properties and excellent flame-retardant and heat-insulating capabilities, and has a wide application prospect in the field of flame retardance and heat insulation.

The invention discloses an ionic liquid modified polyimide nanofiber film and an air purification filter screen based on the ionic liquid modified polyimide nanofiber film, and belongs to the technical field of film filtering materials. The preparation method comprises the following steps: firstly, selecting a diamine monomer and a dianhydride monomer to carry out low-temperature polycondensation reaction, and then carrying out solvent replacement and freeze drying to obtain polyamide acid powder; dissolving the powder to obtain a polyamide acid spinning solution, preparing an ionic liquid / polyamide acid spinning solution on the basis, and carrying out electrostatic spinning to obtain an ionic liquid / polyamide acid nanofiber membrane; and finally, carrying out high-temperature thermal imidization treatment to prepare the ionic liquid / polyimide nanofiber membrane. The method is simple and efficient, the problems of low resistance, high pressure drop and the like of a traditional nanofiber film in air filtration are solved, development and application of the nanofiber film in the field of air filtration are further widened, and the nanofiber film has important scientific significance and application value in the fields of high-temperature filtration, gas adsorption and the like.

The invention discloses a preparation method of a cellulose acetate / thermoplastic polyurethane / polypyrrole composite conductive nanofiber aerogel composite pressure sensing material. The preparation method comprises the following steps: (1) preparing a cellulose acetate and thermoplastic polyurethane spinning solution; (2) preparing a cellulose acetate / thermoplastic polyurethane composite nanofiber membrane; (3) preparing cellulose acetate / thermoplastic polyurethane short nano dispersion liquid; (4) preparing a cellulose acetate / thermoplastic polyurethane / polypyrrole polymerization solution; and (5) preparing the cellulose acetate / thermoplastic polyurethane / polypyrrole composite conductive nanofiber aerogel. According to the preparation method, a high-temperature thermal annealing process is not needed, and the prepared nanofiber composite aerogel has high conductivity, ultralow volume density, high compression deformation performance and high pressure resistance sensing sensitivity.