31results about How to "Shape is easy to control" patented technology

The application belongs to the technical field of optical materials, and particularly discloses a synthesis method of core-shell quantum dots based on surface activation, which comprises the following steps: S1, preparing a quantum dot core; S2, degassing reaction is carried out on zinc precursor, octadecene and oleylamine in proportion, then the quantum dot core obtained in S1 is injected, a metal alkyl compound is added, and the temperature is increased to 230-250 DEG C; S3, the shell precursor is injected for 3-4 times, the temperature is increased at the same time, the inner shell is grown, zinc stearate and TOP-S are injected again, the ZnS shell is grown, and the InP core-shell quantum dots with regular morphology are obtained. The synthesis method of core-shell quantum dots based on surface activation is adopted, the quantum dots with controllable morphology and size distribution are obtained, the method is suitable for industrial production, and has wide applicability.

This invention discloses a samarium-lanthanum co-doped calcium oxyborate yttrium nonlinear optical crystal material, its preparation method, and its applications. The samarium-lanthanum co-doped calcium oxyborate yttrium nonlinear optical crystal material belongs to the monoclinic crystal system, has a space group of Cm, and a chemical formula of Sm. 0.3 La 0.1 :Y 0.6 Ca4O(BO3)3 has a second harmonic response intensity of 0.89 × KDP, and exhibits transmittance exceeding 80% in the 500–1000 nm and 1600–2400 nm wavelength ranges. It also has a strong absorption peak in the 1000–1600 nm wavelength range. Therefore, the samarium-lanthanum co-doped calcium oxyborate yttrium nonlinear optical crystal can be considered as a nonlinear optical crystal material with broad application prospects in the field of optics.

The utility model discloses plastic material production equipment, relates to the technical field of positive and negative electrode material preparation equipment, and aims to solve the problem of structural regulation and control of the conventional positive and negative electrode material preparation. Comprising a box body and a cylinder body, the box body is communicated with the cylinder body through an adapter, and heating assemblies for heating the interiors of the box body and the cylinder body are arranged on the box body and the cylinder body; a feeding port communicated with the interior of the box body is formed in the box body, a conveying belt is further arranged in the box body, the conveying belt is driven by a conveying motor, a roller column is further arranged in the box body, the roller column is of a composite structure, and the roller column is arranged above the conveying belt and rolls materials on the conveying belt. The two ends of the cylinder body are rotationally connected with the adapter and the discharging port respectively, the cylinder body is driven by the driving mechanism, the discharging port is formed in the supporting seat, and an inner wall threaded groove is formed in the inner wall of the cylinder body. And meanwhile, the productivity is also improved.

The invention belongs to the technical field of synthesis and preparation of aluminum nitride, and discloses a controllable and extensible preparation method of a one-dimensional aluminum nitride nanowire / nanotube, which comprises the following steps: (1) uniformly mixing a solid aluminum source and a solid nitrogen source, transferring the mixture into a rotatable crucible, transferring the crucible into a tubular furnace, sealing the tubular furnace, and carrying out heat preservation for 2-3 hours; vacuumizing and then introducing protective gas; (2) under the condition that protective gas is continuously introduced, the tubular furnace is heated to a preset target temperature for a nitridation reaction, and the nitridation reaction is carried out under the condition that a crucible rotates at a constant rotating speed; and after the reaction is finished, cooling the tubular furnace and stopping the rotation of the crucible to obtain a one-dimensional aluminum nitride nanowire or nanotube product. According to the method, the solid aluminum source and the solid nitrogen source are used as raw materials, and the crucible rotation is introduced during the nitridation reaction to carry out dynamic enabling improvement, so that the single-crystal aluminum nitride nanowire or nanotube with high purity and uniform morphology can be efficiently synthesized.

This invention discloses high-entropy rare-earth silicate ceramic nanopowders, their preparation methods, and applications. The preparation method of the high-entropy rare-earth silicate ceramic nanopowders of this invention includes the following steps: 1) dissolving rare-earth oxide powder in an acid solution to prepare a rare-earth salt solution, then adding urea and silica powder and performing a gelation reaction to obtain a gel; 2) igniting the gel for combustion synthesis, grinding, and obtaining a precursor powder; 3) calcining the precursor powder to obtain the high-entropy rare-earth silicate ceramic nanopowders. The high-entropy rare-earth silicate ceramic nanopowders of this invention possess excellent characteristics such as fine particle size, uniform elemental distribution, large component space, and absence of impurities. Furthermore, its preparation method has advantages such as fast synthesis speed, simple equipment, simple and controllable process, and low industrialization cost, making it suitable for application in hot-end components of aerospace engines and possessing very broad application prospects.

The application discloses high-entropy rare earth silicate ceramic nano powder and a preparation method and application thereof. The preparation method of the high-entropy rare earth silicate ceramic nano powder comprises the following steps: 1) dissolving rare earth oxide powder in an acid solution to prepare a rare earth salt solution; 2) mixing the rare earth salt solution and a sodium silicate solution, adding ammonia water to perform chemical co-precipitation, then performing standing and aging, and then taking the precipitate to perform drying to obtain a precursor powder; and 3) placing the precursor powder under the condition that the temperature is 1100 DEG C to 1200 DEG C to perform calcination. The high-entropy rare earth silicate ceramic nano powder has excellent characteristics such as small particle size, uniform element distribution, large component space and no impurity phase, and the preparation method has the advantages of low synthesis temperature, simple equipment, simple and controllable process, low industrialization cost and the like, is suitable for being used on a hot end part of an aerospace engine and has a very wide application prospect.

The application provides a self-supporting Ni-Fe-Mn oxygen evolution electrocatalyst and a preparation method thereof, and belongs to the technical field of catalytic material preparation. The Ni, Fe and Mn metal raw materials are repeatedly smelted, and after smelting, suction casting is carried out to obtain a cast plate. The cast plate is subjected to homogenization treatment, and then is cut and polished. Finally, etching is carried out in a nitric acid solution to obtain the self-supporting Ni-Fe-Mn oxygen evolution electrocatalyst. The self-supporting electrocatalyst is prepared by the method of arc smelting, heat treatment and chemical etching, and has the advantages of simple preparation process, easy industrialization, adjustable size, excellent stability and excellent OER performance.

This invention belongs to the field of environmental protection and resource recycling technology, specifically relating to a method for preparing high-purity basic magnesium carbonate from low-grade magnesite. The method includes the following steps: S1, crushing the low-grade magnesite and mixing it with an acid solution for acid leaching to obtain an acid leaching solution; S2, removing impurities from the acid leaching solution to obtain a refined solution; S3, absorbing the carbon dioxide gas released during the acid leaching step using an absorbent to obtain a carbon dioxide-loaded solution; S4, mixing the refined solution and the carbon dioxide-loaded solution for precipitation to obtain basic magnesium carbonate product and a protonated absorbent solution; S5, recovering the acid and regenerating the absorbent solution from the protonated absorbent solution using a bipolar membrane electrodialysis device. This invention utilizes the CO2-loaded solution as a precipitant to react with the Mg in the refined solution. 2+ The reaction produces basic magnesium carbonate. The reaction conditions are mild, and the crystal morphology and particle size are easy to control, thus obtaining a high-value-added product that meets market demands.

The invention discloses a lanthanum ion doped oxygen calcium yttrium borate nonlinear optical crystal material and a preparation method thereof, the lanthanum ion doped oxygen calcium yttrium borate nonlinear optical crystal material belongs to a monoclinic system, the space group is Cm, the chemical formula is La0.1: Y0. 9Ca4O (BO3) 3, the frequency multiplication coefficient is 2 * KDP, the ultraviolet cut-off edge is less than 200 nm, and no absorption peak with the intensity greater than or equal to 0.2 cm <-1 > exists in the range of 200-2500 nm. Therefore, the lanthanum ion doped yttrium calcium oxide borate crystal can be used as a nonlinear optical material with a wide application prospect in the field of optical parameter chirped pulse amplification.

The application relates to the hydrogen energy preparation technical field, in particular to a methanol cracking hydrogen production carbon process and system, the methanol cracking hydrogen production carbon process comprises the following steps: a, preparing methanol gas; b, methanol cracking is carried out through a catalyst system: under an argon atmosphere, the catalyst system is heated to a predetermined temperature, the methanol gas is introduced, and methanol cracking hydrogen production carbon is carried out; the catalyst system comprises an alloy catalyst and a modified metal oxide catalyst; c, product collection: collecting hydrogen and carbon material obtained by cracking. The application provides a methanol cracking hydrogen production carbon process and system, so as to solve the problems of insufficient catalyst activity and selectivity, large reactor energy consumption and high investment.

The invention discloses a process and a method for preparing a nano material. Specifically, lithium iron phosphate, composite sodium iron phosphate and calcium carbonate are efficiently prepared by adopting a sol-gel method and a precipitation method respectively. When the lithium iron phosphate and the composite sodium iron phosphate are prepared, the reaction process is controllable by regulating and controlling the oscillation condition, the reaction temperature, the pH value and the retention time, and a target product is obtained after the gel is calcined. When calcium carbonate is prepared, nucleation and crystallization are enhanced by controlling the flow rates of a precursor, a precipitator and a surfactant and combining oscillation. According to the method, mixed mass transfer is enhanced by means of periodic oscillatory flow, local supersaturation and concentration gradient are inhibited, reactant deposition and channel blockage are reduced, continuous and stable production is guaranteed, meanwhile, the use amount and cost of a surfactant are reduced, and accurate regulation and control over the particle size, morphology and distribution of the material are achieved. Compared with a traditional process, the preparation period is greatly shortened, the product purity and the reaction efficiency are improved, and the method is suitable for industrial continuous production and has remarkable economic benefits and social benefits.

This invention provides a method for preparing a three-dimensional textured macroporous carbon composite with adjustable carbon shell morphology, comprising the following steps: S1, dispersing a phenolic prepolymer in a solvent to prepare a phenolic prepolymer slurry; S2, adding graphene oxide to the prepared phenolic prepolymer slurry, mixing well, and preparing a carbon precursor spraying liquid; S3, spraying the prepared carbon precursor spraying liquid onto a planar fiber carrier to obtain a carbon precursor carrier composite; S4, heat-treating the carbon precursor carrier composite to obtain three-dimensional hollow porous carbon. This invention uses planar fiber materials as the reaction site, eliminating the need for other templates, and uses graphene oxide as the key component of the carbon precursor. Combining the advantages of continuous operation technology such as ultrasonic dispersion and atomized spraying, the carbon precursor is composited on the surface and interior of the carrier. After heat treatment, three-dimensional hollow porous carbon is prepared. The morphology of the carbon shell composited on the three-dimensional textured macroporous carbon framework can be controlled simply by adjusting the content of the key components in the carbon precursor.

The present application adopts inkjet printing and non-catalyst chemical nickel plating method to deposit metal nickel on transparent nylon net and silk net, realizes the preparation of low-cost large-scale flexible transparent conductive substrate with controllable morphology, and is suitable for large-scale mass production. The present application is very beneficial to the integration of planar microelectronic devices. Based on the technology, a flexible transparent Zn net electrode is prepared by electroplating Zn on the Ni-P pattern nylon net. The ZECD window with zinc net anode and prussian blue (PB) cathode shows significant electrochromic performance, including fast switching time, high optical contrast and excellent cycle performance. These ZECDs are also very suitable for solar charging intelligent windows, which can further solve the problem of solar intermittency. These findings open up new opportunities for energy storage and conversion transparent devices.

The invention relates to the technical field of novel electro-catalysis materials, and discloses a fullerene modified carbon loaded amorphous niobium oxide nano island confinement osmium-based ultra-small cluster electro-catalyst as well as a preparation method and application of the fullerene modified carbon loaded amorphous niobium oxide nano island confinement osmium-based ultra-small cluster electro-catalyst. Amorphous niobium oxide (NbOx) and osmium (Os) clusters are uniformly loaded on the carbon substrate material, the amorphous niobium oxide is in a nano island form, and the average particle size of the osmium (Os) clusters is 0.8-1.2 nm. The ultrathin nano carbon sheet FDC prepared by modification of fullerene has the characteristics of excellent conductivity and high specific surface area, so that active components are fully exposed, the phase interface contact area is increased, and the heterogeneous catalysis behavior is greatly promoted. The electrocatalyst has excellent electrocatalytic activity and stability, the active components of the electrocatalyst have the characteristics of small particle size, uniform particle distribution and the like, and the problems of reduction of catalytic performance and the like caused by reduction of active sites due to overlarge particles of the active components in the electrocatalyst with a composite structure are solved.

The invention relates to the technical field of nickel-based powder, in particular to a preparation method and a preparation device of nano nickel-based powder, and the preparation method comprises the following steps: A, uniformly mixing nickel salt, a reducing agent, an additive and a solvent, and adjusting the pH value to 8-12 to obtain a precursor solution; b, the precursor solution is subjected to a reaction for 10-60 s and 10-60 min in a nucleation temperature section and a growth temperature section in sequence respectively, and then is frozen for 5-20 min in a freezing temperature section, and a nano nickel-based particle mixture is obtained; wherein the temperature of the nucleation temperature section is higher than that of the growth temperature section, and the temperature of the growth temperature section is higher than that of the freezing temperature section; and C, sequentially separating, washing and drying the nano nickel-based particle mixture to obtain the nano nickel-based powder. According to the preparation method of the nano nickel-based powder and the preparation device of the nano nickel-based powder, on the premise that the production cost is reduced, it is guaranteed that the size uniformity, dispersity and morphology of the nano nickel-based powder are controllable.

The application discloses a kind of zeolite molecular sieve for removing hexavalent chromium in wastewater and its preparation method, which comprises the following steps: mixing solution and stirring: all raw materials are placed into polytetrafluoroethylene lined stainless steel autoclave, then the polytetrafluoroethylene lined stainless steel autoclave is placed into ultrasonic cleaning machine for ultrasonic stirring, and slowly shakes during stirring process;Synthesis reaction: after stirring, the polytetrafluoroethylene lined stainless steel autoclave is tightened, the polytetrafluoroethylene lined stainless steel autoclave is placed into thermostat for constant temperature reaction;Sample removal: after constant temperature, the polytetrafluoroethylene lined stainless steel autoclave is taken out, the cover is rotated after cooling, the white lining is taken out, and is dried, to obtain molecular sieve.The application can solve the problems of complex process flow, huge energy consumption and inconvenient operation in the synthesis technology of existing molecular sieve.

The application discloses a morphology-controllable graphdiyne two-dimensional metal organic framework material and a preparation method and application thereof, a coordination reaction is carried out between a -C=C-C=C- functionalized hydroxyl ligand and a transition metal ion under a solvothermal condition to form a high-crystallinity and high-conjugation graphdiyne two-dimensional MOF; richly embedded acetylene serves as a promising active site to assist photogenerated exciton migration, so that the performance of photocatalytic hydrogen production can be possibly improved; a surfactant CTAB is used to control the morphology to obtain a solid hexagonal prism, a hexagonal flaky structure or a hexagonal prism hollow tube structure material, the material has a high surface volume atom ratio and rich surface modification sites, which helps to reduce diffusion barriers, promote the contact of reactants and active sites, accelerate mass transfer and charge transfer, and further improve the performance of photocatalytic hydrogen production.

The application discloses a synthesis method of rare earth borate nanoparticles, which comprises the following steps: heating a boron precursor in a nitrogen atmosphere, then rapidly injecting a rare earth metal precursor, rapidly heating to 280-310 DEG C and maintaining for a period of time to form uniform rare earth borate nanoparticles; wherein the rare earth metal precursor is an organic solution containing rare earth acetate hydrate and oleic acid; and the boron precursor is an organic solution containing tributyl borate. The application firstly innovatively improves the synthesis method of rare earth borate nanoparticles, prepares regular morphology and uniform size neodymium borate nanoparticles, and after optical performance characterization, it is shown that the neodymium borate nanoparticles have the potential for BNCT used for near-infrared two-zone imaging guidance. The preparation method can realize the size control of the neodymium borate nanoparticles by adjusting the proportion of the neodymium precursor and the boron precursor, and is suitable for the preparation of various rare earth borate nanoparticles, and the method has universality.

The application discloses a high-entropy rare earth silicate ceramic powder and a preparation method and application thereof. The preparation method of the high-entropy rare earth silicate ceramic powder comprises the following steps: 1) mixing rare earth oxide powder, SiO2 powder, LiCl and KCl and grinding to obtain a mixed powder; and 2) calcining the mixed powder under the condition that the temperature is 700 DEG C to 900 DEG C, and then performing water washing and drying to obtain the high-entropy rare earth silicate ceramic powder. The high-entropy rare earth silicate ceramic powder has the excellent characteristics of high purity, small particle size, uniform element distribution and large component space, and the preparation method has the advantages of short preparation period, low synthesis temperature, small energy consumption and high efficiency, is suitable for being used on a hot end part of an aerospace engine and has a very wide application prospect.

This invention discloses a method for preparing copper-based nanomaterials rich in two-dimensional defects and their application in electrocatalytic CO2 reduction. The method involves inducing two-dimensional defects in the copper-based nanomaterials through halogen (F, Cl, Br, and I) doping during electrochemical deposition, thereby obtaining copper-based nanomaterials rich in two-dimensional defects. This invention, through electrochemical deposition, effectively incorporates halogen elements into copper nanomaterials, inducing different defects and active sites, enhancing the adsorption capacity of reaction intermediates, and improving the conversion of carbon dioxide (eCO2RR) to more carbon (C) atoms. 2+ The conversion efficiency of the product can be affected, and the type and size of defects can also be changed by adjusting the type and concentration of halides in the electrolyte.

This invention belongs to the technical field of automotive steel manufacturing, specifically relating to a green, low-carbon high-strength automotive steel and its preparation method. The invention adds nickel-doped modified niobium carbide to the high-strength steel, dispersing it in the iron matrix to effectively improve the strength and toughness of the steel plate and increase its porosity. Simultaneously, the addition of Ca, Mg, and lanthanum and cerium carbonate as composite refining agents to the alloy melt improves casting quality and mechanical properties. Furthermore, precise control of the composition of elements such as C, Mn, Si, Cr, Mo, Cu, and Ti, combined with hot rolling, cold rolling, continuous annealing, or hot-dip galvanizing processes, enables the material to possess both high strength and excellent porosity.

This invention belongs to the field of polyolefin recycling technology and relates to a method for preparing high-quality carbon nanotubes by catalytic carbonization of polyolefins. In this invention, polyolefins are degraded at high temperature to generate small-molecule hydrocarbons. Subsequently, a Ni-Mo-Al catalyst undergoes a reduction reaction to generate elemental nickel. The elemental nickel catalyzes the degradation products to undergo dehydrogenation, cyclization, and aromatization reactions, followed by carbon deposition on the surface of the elemental nickel, which gradually grows into carbon nanotubes. Furthermore, the Ni-Mo-Al catalyst can reduce the formation of amorphous carbon, thereby increasing the activity of elemental nickel and reducing its ability to dissolve carbon, thus preparing carbon nanotubes with smaller diameters and uniform morphology. This invention has the advantages of inexpensive and readily available carbon sources and a simple preparation method, realizing the upgraded chemical recycling of waste polyolefins and the controllable preparation of carbon nanotubes, effectively solving the problem of reusing urban and industrial waste polyolefins.

The present application relates to the field of precursor polymer drug preparation, in particular to a malonic acid precursor polymer self-assembly nanodrug preparation and application taking malonic acid as a loading object. The present application forms a drug precursor polymer through a covalent connection mode of a malonic acid precursor molecular drug, solves the metabolic kinetics obstacle of malonic acid, and increases the bioavailability of malonic acid. The present application can effectively release malonic acid as a specific inhibitor of succinate dehydrogenase in an oxidative state, has the advantages of non-toxicity, non-immunogenicity and degradability. And the polymer of the present application can self-assemble to form a nanodrug, and has stronger curative effect on the inhibition of succinate dehydrogenase in some mitochondrial metabolic activities, and has potential application value in the preparation of myocardial infarction treatment drugs. The preparation process of the present application is simple, the components are clear, and the quality is controllable.

The application provides a preparation method of nano silver powder with single particle dispersion. The method aims at solving the problems of easy agglomeration, high impurity and high cost of nano silver powder in the prior art. The method comprises the following steps: preparing an oxidizing agent solution containing a high molecular carboxylic acid or a salt thereof, a reducing agent solution, and a bottom solution containing a dispersant and a silver ion release regulator respectively; adjusting the pH of the bottom solution, and adding the oxidizing agent and the reducing agent solutions at the same flow rate to react; then, the target product is obtained through flocculant sedimentation purification, cleaning, drying and air grinding. The method controls the release of silver ions and the reaction rate through the synergistic effect of the high molecular carboxylic acid or the salt thereof, the silver ion release regulator and the like, and realizes the single particle dispersion of the nano silver powder without a large amount of dispersant, and is suitable for the fields of electronic information, biomedicine and the like.

The invention discloses a constant-temperature electronic nose system with self-adaptive flow control and a control method of the constant-temperature electronic nose system. The device comprises a gas source conditioning module, a constant-temperature gas chamber, a gas transmission module, a gas detection module and a control module, the gas source conditioning module comprises a filter and a mass flow controller, the constant-temperature gas chamber comprises a heat preservation shell, a sample container, a heater and a temperature sensor are arranged in the heat preservation shell, and the gas inlet end of the filter is connected with a first external carrier gas source; the air outlet end of the filter is connected with the air inlet end of the mass flow controller, the air outlet end of the mass flow controller is connected with an air inlet connector in the top of the sample container through a first connecting pipeline, and an air outlet connector in the top of the sample container is connected with the air inlet end of the air conveying module through a second connecting pipeline. The gas outlet end of the gas transmission module is connected with the gas inlet of the gas detection module. The carrier gas flow can be automatically adjusted according to the actual response of the gas sensor, and saturation of the gas sensor is avoided while the signal intensity is ensured.

The application discloses a method for preparing spherical-like trimanganese tetraoxide by an emulsion one-step method and belongs to the technical field of inorganic material preparation. The method uses soluble manganese salt as raw material, adopts water-in-oil emulsion micelles as a soft template, limits manganese ions in the spherical micelles, uses ammonia and ammonium salt buffer to stabilize the reaction pH, first prepares crystal seeds, then carries out parallel flow feeding and controllable oxidation, and finally obtains the spherical-like trimanganese tetraoxide through ripening, filtration, washing and drying. The application solves the problems of high cost, strict pH control and difficult morphology control in the traditional process, has the advantages of simple process, low cost, uniform morphology, high purity and the like, and the prepared product is suitable for battery-grade lithium manganate precursor and is suitable for industrial production.

The application belongs to the field of carbon monoxide treatment and catalytic oxidation in sintering flue gas, and discloses a preparation method and application of a ceria-supported bimetallic catalyst. A cerium source, a surfactant, a complexing agent and a crosslinking agent solution are mixed, and the pH is adjusted to make metal ions form hydroxide precipitates to obtain a precursor turbid solution. After hydrothermal reaction, the precursor turbid solution is filtered, washed, dried, ground and calcined to obtain a precursor powder. The precursor powder is dispersed, and a bimetallic solution is gradually added dropwise. The ceria-supported bimetallic catalyst is obtained through drying and calcination treatment. 3+ The surfactant, the complexing agent and the crosslinking agent are introduced to synergistically regulate Ce Hydrolysis, inhibit grain growth and construct three-dimensional network limited space, obtain small grain, large specific surface area, rich in defects of ceria carrier, make it uniform dispersion, enhance metal-support interaction, promote alloy phase or hetero-interface formation, so as to significantly improve the stability of catalytic active center, selectivity.

The invention relates to the technical field of semiconductor materials, in particular to a method for inducing black phosphorus lines to preferentially grow by stacking substrates, which comprises the following steps: firstly, uniformly mixing red phosphorus, metallic tin and iodine according to a certain proportion, and placing in a reactor; then, the silicon / silicon dioxide substrate coated with the gold film is subjected to pre-annealing treatment, raw materials are isolated in a reactor through a porous medium, and the annealed substrate is placed at the other end of the reactor; finally, placing the reactor in a heater for heating reaction, and naturally cooling to room temperature after the reaction is finished; and taking out the substrate to obtain black phosphorus in different forms. According to the method, chemical vapor transport is utilized, a gold film is pretreated firstly, so that the gold film is converted into dispersed gold particles at high temperature, and black phosphorus is induced to grow by taking nano-particles as a core. And through stacking of the silicon wafers, space confinement growth is realized to control the number and length of the whole black phosphorus wires, so that controllable preparation of black phosphorus on the substrate is realized, the whole reaction is mild, the reaction conditions are relatively low, and the cost is relatively low.

The invention discloses a synthesis method of porous polylactic acid microspheres, and belongs to the field of biomedical materials. The method comprises the following steps: preparing a first water phase taking a water-soluble polymer as a pore-foaming agent, and dispersing the first water phase in a polylactic acid organic solution to form a water-in-oil-in-water primary emulsion; introducing the primary emulsion into a curing bath containing a poor solvent, so that the organic solvent is extracted, the polylactic acid is cured, and microspheres wrapping pore-foaming agent liquid drops are formed; and finally, washing to remove the pore-foaming agent to form a porous structure. The core of the method is that the internal water-phase liquid drops are used as a sacrificial pore-forming template, and the microspheres are cured by a solvent extraction method. The method is mild in condition, green and environment-friendly, the aperture, porosity, particle size and pore connectivity of the microspheres can be independently and accurately regulated and controlled by adjusting parameters such as emulsification conditions and phase proportion, and the prepared microspheres have the characteristics of open pores and high connectivity and have excellent application prospects in the fields of drug sustained release and tissue engineering.

This invention belongs to the field of inorganic nanofiber materials technology, specifically relating to a highly flexible boron nanofiber (BN) ceramic nanofiber and its preparation method. Using boric acid and melamine as main raw materials, this invention prepares the nanofiber through a complexation reaction, solution preparation, electrospinning, and heat treatment. The raw materials are inexpensive, the process is simple, and it is easy to scale up production. By heating the electrospinning needle at 90-120℃, the viscosity of the precursor needle tip is reduced, preventing premature crystallization of the complex and completely solving the needle clogging problem, ensuring continuous and stable spinning, and improving spinning efficiency and fiber quality. The resulting BN nanofibers are continuous, have uniform diameter, and a smooth surface. The controllable transformation from amorphous BN to highly crystalline hexagonal boron nitride can be achieved by adjusting the heat treatment temperature. The amorphous BN nanofiber felt has extremely low thermal conductivity (≤0.029 W / (m·K)) and excellent compression resilience, making it suitable as a reinforcement for composite materials or directly applicable in high-temperature filtration, high-efficiency heat insulation, and catalyst carriers.