92results about How to "Uniform pore size" patented technology

The invention relates to a fat cutting filter, a fat cutting filtering method and a fat cutting filtering device.The fat cutting filter comprises a shell, the interior of the shell is a treatment cavity, and the shell is provided with a first connector and a second connector which communicate with the treatment cavity; the cutting part is located in the treatment cavity and located between the first connector and the second connector, the cutting part comprises a rigid silk screen used for cutting fat, and the silk diameter of the rigid silk screen ranges from 0.05 mm to 1 mm. The mesh wires of the rigid silk screen are used for fat cutting, the structure is simple, operation is easy, convenient and efficient, the machining cost is low, the mesh diameter can be customized according to needs, the porosity can reach 90% or above, the cutting efficiency is high, and the problem of filtering blockage during fat cutting can be effectively solved.

The invention discloses a low-temperature sintering asymmetric porous silicon carbide ceramic membrane separation layer and a preparation method thereof, the preparation method comprises the following steps: a) preparation of a coating liquid: firstly dispersing a binder in a solution, adding silicon carbide particle powder, carrying out magnetic stirring dispersion for a period of time, then adding a dispersant, and stirring; then putting the stirred and mixed film coating liquid and the grinding balls into a ball milling tank for ball milling; and adjusting the pH value of the ball-milled silicon carbide coating liquid with ammonia water, and carrying out vacuum defoaming to finally obtain the high-stability and uniformly-dispersed silicon carbide coating liquid. Wherein the addition amount of the silicon carbide coarse particles is 0.5-50 wt% of the mass of silicon carbide; b) coating; c) drying; and d) sintering. The asymmetric porous silicon carbide ceramic membrane prepared by the method is low in sintering temperature, and the prepared separation layer membrane is controllable in pore size and uniform in pore size distribution; the method has excellent application prospects in the field of membrane separation.

The invention relates to the field of sponge materials, and provides an antibacterial degradable sponge material and a preparation method thereof. The material is prepared from protocatechuic acid modified quaternized chitosan, quaternary ammonium salt grafted gelatin, sodium alginate, polyhydroxybutyrate, polycaprolactone, a polylactic acid-glycolic acid copolymer, hexamethylene diisocyanate, a foaming agent, nano cellulose, vitamin E, polyethylene glycol, triethylamine and dimethylformamide. Protocatechuic acid and quaternized chitosan are subjected to amidation modification, and chitosan and gelatin are subjected to quaternization treatment by adopting 2, 3-epoxypropyl trimethyl ammonium chloride, so that the antibacterial property and biodegradability of the material are improved. In the material preparation process, through vacuum degassing, foaming vacuum degree and humidity control and a multi-step drying process, it is ensured that the average pore size of the material is uniform (50-200 microns) and the porosity is high (50%-90%), and the obtained material has excellent antibacterial property and degradability and has wide application value.

The invention provides a preparation method of spherical iron phosphate, and relates to the technical field of lithium ion batteries, and the preparation method comprises the following steps: S1, one-step reaction: carrying out parallel flow on an iron salt solution, a phosphorus salt solution and ammonia water according to a molar ratio of 1: (0.8-1.2): (0.8-1.1) to generate amorphous iron phosphate slurry; adding ammonia water into the iron phosphate slurry to adjust the pH value to 1.5-2.5; s2, membrane washing; s3, a second-step reaction: adding pure water into the washed iron phosphate slurry, adjusting the iron concentration to 0.5-1.2 mol / L, adding a phosphoric acid solution, heating to 90-120 DEG C, and controlling the heat preservation time for 30-90 minutes after the material is converted into a white material, so as to obtain white slurry; s4, washing: taking a filter cake; s5, drying: generating iron phosphate dihydrate; s6, calcining: spherical iron phosphate is generated, and the iron phosphate is successfully converted from a traditional olive type, peanut type or honeycomb type to a spherical type through the preparation method provided by the invention.

The invention provides a dopamine hybrid ligand ZIF-8 / gelatin composite aerogel and a preparation method and application thereof, and belongs to the field of composite aerogel and preparation thereof.The growth rate of ZIF-8 nanocrystals is accurately controlled through dopamine hybrid coordination metal ions, stable ZIF-8-DA hybrid crystals are formed, and the stability of the aerogel is improved. The crystal not only solves the problem that the traditional MOF material is easy to aggregate particles, but also retains abundant chemical functional groups; furthermore, the ZIF-8-DA and a gelatin matrix are compounded by adopting a multi-crosslinking strategy and a freeze-thaw treatment technology to obtain the composite aerogel with a unique three-dimensional porous microstructure, so that the mechanical strength and the structural stability of the composite aerogel are remarkably improved, and the composite aerogel shows better heat-insulating and flame-retardant properties; the composite aerogel material prepared by the scheme has excellent heat insulation and flame retardant properties, and is suitable for high-energy-consumption fields such as building energy conservation, industrial heat management and environmental flame retardance.

The invention discloses a preparation method of a fluoride-free waterproof breathable film based on an irradiation technology. Comprising the following steps: uniformly mixing chitosan, an organosilicon polymer, a cross-linking agent, a catalyst, a pore forming agent and a solvent according to a ratio, and stirring until complete dissolution to prepare a membrane casting solution; coating the surface of a membrane treated by an irradiation technology with the membrane casting solution by using a blade coating machine to form a coated membrane; and drying the coating film to obtain the waterproof breathable film. The structure of the base film and the coating is adopted, so that the overall structural strength is improved, and the membrane can be placed under certain water pressure. The pore diameter and the pore density of the base membrane can be regulated and controlled, a pore-foaming agent is added into the coating, and the overall air permeability of the waterproof and breathable membrane can be flexibly regulated and controlled according to requirements. The organosilicon polymer and the cross-linking agent in the coating enhance the hydrophobicity, the mechanical strength and the durability of the coating. The waterproof breathable film prepared by the invention adopts fluorine-free substances. The waterproof breathable film prepared by the invention has a good application prospect in the field of electronic products.

The invention belongs to the field of gas technical purification, and particularly relates to a honeycomb-shaped high-concentration NO2 adsorption trapping material as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) preparing adsorbent slurry by taking high-silicon molecular sieve raw powder as a raw material; (2) putting a honeycomb carrier into the adsorbent slurry for dipping and coating; and (3) naturally airing, drying and roasting the impregnated carrier to obtain the integral honeycomb-shaped high-concentration NO2 adsorbing and trapping material. On the basis of the honeycomb-shaped high-concentration NO2 adsorption trapping material (the molecular sieve silica-alumina ratio is 1000-5000), NO2 is efficiently trapped through a pressure swing adsorption technology, meanwhile, the adsorbent subjected to adsorption saturation is reversibly regenerated, high-concentration NO2 desorbed gas is obtained, NO2 recycling is achieved, NOx tail gas of a nuclear industry post-treatment plant is recycled, and the purpose of recycling the NOx tail gas of the nuclear industry post-treatment plant is achieved. A stable NO2 gas source is provided for a spent fuel post-treatment main process, the dual requirements of NO2 raw material preparation and tail gas denitration of a post-treatment plant are met, and purification and recycling of NO2 are achieved.

The invention belongs to the technical field of petroleum composition analysis, and particularly relates to a method for separating and analyzing carboxylic acid compounds in petroleum. The method comprises the following steps: 1, dissolving a petroleum sample in an organic solvent A, and adding a solid-phase extraction column filled with an aminated MCM-41 molecular sieve; step 2, eluting the sample with an organic solvent B and the mixed solution C in sequence to obtain the carboxylic acid compound; and 3, dissolving the carboxylic acid compound by using an organic solvent D so as to adjust the sample injection concentration, and characterizing the molecular composition by using an electrospray ionization mass spectrometer. The analysis method provided by the invention can eliminate the influence of a petroleum matrix, and realizes fine separation and analysis of molecular compositions of carboxylic acid compounds in petroleum.

The invention belongs to the technical field of foaming materials, and particularly relates to cellulose modified polyurethane foam with high cohesion, a preparation method and application. The cellulose modified polyurethane foam provided by the invention is obtained by uniformly mixing cellulose or a derivative thereof, isocyanate, an amine catalyst, a foam stabilizer, polyether polyol, an organic metal catalyst and deionized water, heating and curing, wherein the cellulose or the derivative thereof is non-fat-soluble cellulose or a derivative thereof. The cellulose modified polyurethane foam has the characteristics of stable pores, uniform pore diameter, high toughness, high cohesion and compression resistance, and is suitable for portable electronic equipment and precision electronic equipment.

The utility model discloses a self-pressure-relief waterproof loudspeaker with a waterproof and breathable nuclear track vibrating membrane, and belongs to the technical field of loudspeakers. Comprising a loudspeaker support, a nuclear track waterproof breathable vibrating membrane and a loudspeaker surface cover, the nuclear track waterproof breathable vibrating membrane is composed of a nuclear track membrane, one end of the loudspeaker support is provided with a loudspeaker magnetic circuit, loudspeaker coils are arranged inside and outside the loudspeaker magnetic circuit, and the loudspeaker coils are fixedly connected with the nuclear track waterproof breathable vibrating membrane. The loudspeaker surface cover presses the edge of the nuclear track waterproof breathable vibrating membrane on the loudspeaker support. Compared with a first-generation self-pressure-relief waterproof loudspeaker, the self-pressure-relief waterproof loudspeaker is simple in production process. The nuclear pore waterproof and breathable vibrating membrane achieves waterproof and breathable functions, is high in mechanical strength and good in toughness, and meets the requirements of deep waterproof products for toughness and high-pressure tearing of the waterproof and breathable membrane. The nuclear track membrane is good in air flow consistency, can meet the requirements of an electronic product with a built-in air pressure sensor and an electronic product for accurately measuring the current altitude, and has deep waterproof and air leakage functions.

The utility model discloses an impeller-type fast-forward drill bit which comprises a drill bit body, one end of the drill bit body is provided with a spline section used for being fixedly connected with a drill rod, the other end of the drill bit body is provided with a hemisphere, a conical transition section is arranged between the hemisphere and the spline section, and a plurality of alloy ridges are distributed on the hemispherical surface of the hemisphere. The alloy ridges are all distributed around the center point of the top end of the hemisphere in a diverging and circumferential mode, powder discharging grooves are defined by the adjacent alloy ridges, spherical teeth are distributed on the alloy ridges, and a high-pressure air hole is formed in the center of the drill bit body in a penetrating mode. The semi-spherical drill bit is simple in structural design and convenient to operate, through the structure of the semi-spherical body and the conical transition section, rock drilling chambering positioning is accurate, the drilling footage speed is high, holes are standard, it can be guaranteed that the hole diameters are consistent, the powder discharging groove is formed in the end face, rock residues can be smoothly discharged, repeated crushing is avoided, the service life of the drill bit is greatly prolonged, and the service life of the drill bit is prolonged. Sampling personnel can sample conveniently and quickly, and the use requirement is met.

This invention relates to the field of battery separator materials technology, specifically to MXene-functionalized aramid paper-based battery separators, their preparation methods, and applications. Meta-aramid paper is prepared by wet papermaking using short-cut meta-aramid fibers and precipitated fibers. MXene nanosheets are prepared by hydrofluoric acid etching. Using the meta-aramid paper as a substrate, a functional coating is constructed on the surface of the aramid paper by loading a mixture of para-aramid nanofibers and MXene through a vacuum-assisted filtration-layer-by-layer self-assembly method. The resulting functionalized separator is obtained through protonation reduction. The separator, with its three-dimensional porous protective layer constructed from para-aramid nanofibers and MXene, combines physical barrier and chemical bonding, effectively inhibiting polysulfide shuttle. Furthermore, the highly active sites of MXene can activate inert sulfur-containing substances, improving sulfur utilization. When used in assembling lithium-sulfur batteries, the separator achieves an initial discharge capacity of 1244 mAh·g at a constant current density. ‑1 The capacity retention rate is 82% after 200 cycles.

This invention relates to the field of polymer foaming materials technology, and discloses a plant fiber composite nucleating agent for microfoaming of biodegradable materials and its application. The plant fiber composite nucleating agent is made from raw materials comprising the following parts by weight: 80-95 parts of primary ultrafine plant fiber powder, 5-20 parts of surface modifier, and 0.1-5 parts of dispersing lubricating wax; the surface modifier and dispersing lubricating wax are coated on the surface of the primary ultrafine plant fiber powder. The application steps are as follows: adding the plant fiber composite nucleating agent to a biodegradable material matrix to obtain a pre-foaming blend, introducing foaming gas or adding a chemical foaming agent for foaming treatment. The nucleating agent of this invention improves the compatibility between plant fibers and hydrophobic biodegradable matrices, provides heterogeneous nucleation sites in the matrix while increasing the polymer melt strength, inhibits cell coalescence and rupture, and obtains microfoamed materials with uniform pore size. Furthermore, the nucleating agent itself is completely biodegradable.

The present invention relates to a method of manufacturing a liquid cosmetic impregnation foam and the foam, the method including a test method for the liquid cosmetic impregnation foam. The test method for the liquid cosmetic impregnation foam according to one embodiment of the present invention can include the steps of: manufacturing a liquid cosmetic impregnation foam capable of being used to impregnate a liquid or solid cosmetic composition; performing an FT-IR test on the manufactured liquid cosmetic impregnation foam; determining whether a result value of the FT-IR test is within a specific ratio range that provides a balance of hydrolysis resistance, water resistance, and oil resistance of the liquid cosmetic impregnation foam; and if the result value of the FT-IR test is within the specific ratio range, performing a solid NMR test.

The invention relates to the technical field of food-grade materials, in particular to a food-grade porous material and a preparation method thereof. The preparation method comprises the following steps: gradually carrying out enzymolysis on corn flour by alkaline protease and amylase under the conditions of proper temperature and pH, continuously stirring, adding food-grade vegetable gum, and forming porous glycoprotein under the assistance of ultrasonic waves; the porous glycoprotein is uniform in pore size and is 0.5-3 microns, and the surface of the porous glycoprotein is rich in functional groups, so that the porous glycoprotein has good adsorption performance and has very high adsorbability on hydrophobic compounds such as metal ions, pesticide residues, kitchen oil stains and the like. The preparation process is simple, chemical reagents do not need to be introduced, and safe and non-toxic substances are completely adopted as materials for preparing the porous material, so that the product is food-grade, small in damage to human bodies and the environment and wide in application in the food field.

The application relates to a glass substrate via hole method, a Mini-LED substrate and a device. The glass substrate via hole method comprises the following steps: providing a glass substrate, the glass substrate having opposite A and B surfaces; performing laser treatment on the A surface to form pre-penetration array dots, and performing film coating treatment on the B surface to form a protective film; and performing via hole treatment on the glass substrate by using a first etching solution containing HF and H2SO4 to form a via hole extending from the pre-penetration array dots on the A surface to the B surface. The via hole method provided by the application can form a large number of via holes with regular hole shapes, uniform hole diameters and high via hole rates on the glass substrate.

The invention discloses a method for preparing a high-activity water electrolysis hydrogen production catalyst in the field of catalyst preparation. The method comprises the following steps: S1, preparing a polyhedral silicon template by a thermal decomposition method; s2, the polyhedral silicon template is etched to form holes, and a porous silicon template is prepared; s3, preparing MoO3-x (OH) x by an electro-deposition method: connecting the porous silicon template with a cathode of a power supply, and electro-depositing molybdenum on the porous structure of the porous silicon template by taking ammonium molybdate as an electrolyte to prepare MoO3-x (OH) x; s4, vulcanizing MoO < 3-x > (OH) < x > to prepare porous molybdenum disulfide; s5, porous molybdenum disulfide is doped with Co, and the MOS2 / Co catalyst is prepared. According to the scheme, an electrochemical method is combined with a mechanical structure for etching and trepanning, the porous silicon precursor with uniform pore diameter can be prepared, and a stable structure is provided for subsequent preparation of a catalyst.

The present invention proposes a polyionic liquid amphiphilic block copolymer brush and a preparation method thereof and a polyionic liquid photonic crystal porous microsphere containing the same, which belongs to the field of photonic crystal microsphere preparation. Specifically, the norbornene-based ionic liquid hydrophilic block is copolymerized with the hydrophobic block through ring-opening metathesis polymerization to obtain a series of amphiphilic block copolymer brushes with different block ratios and different molecular weights; then the brushes are emulsified together with a surfactant aqueous solution, and the organic solvent is volatilized to obtain polyionic liquid photonic crystal porous microspheres. That is, the present invention introduces charged ionic liquids into porous photonic microspheres by polymerizing ionic liquid hydrophilic blocks, which can be used in various fields such as DNA adsorption, DNA encoding, and sewage purification.

This invention discloses a porous carbon-supported copper catalyst, its preparation method, and its application, belonging to the field of catalyst preparation technology. The invention uses three-dimensional interconnected ordered porous carbon (NCP) with a large-pore structure as a support, tetraphenylporphyrin copper(II) and tetraphenylporphyrin as nitrogen and copper sources, and KOH or NaOH as activators. An NCP precursor adsorbed with tetraphenylporphyrin copper(II), tetraphenylporphyrin, and an alkaline component is obtained through a two-step adsorption process. This precursor is then pyrolyzed at 600-900℃ under nitrogen protection, cooled to room temperature, and washed with water to obtain the porous carbon-supported copper catalyst (NCP@NC-Cu). This catalyst retains a three-dimensional interconnected porous structure, with the active component (copper species) mainly distributed within the pores of the NCP support, and possesses a large specific surface area and abundant nitrogen. The catalyst was applied to the N-formylation reaction of amines with CO2 and H2 to prepare formamide compounds, exhibiting excellent catalytic activity, recyclability, and good substrate versatility, showing promising application prospects.

The invention discloses a preparation method of a metal porous tungsten filter element, and relates to the technical field of powder metallurgy and refractory metal preparation, the preparation method comprises the following steps: dispersing raw material tungsten powder into nearly spherical narrow-particle-size-distribution standby tungsten powder through a jet mill; the tungsten powder to be used is put into a sheath, and a packaging body is obtained through compaction treatment and vacuumizing treatment; carrying out hot isostatic pressing sintering molding on the packaging body, cooling to room temperature, releasing pressure, and demolding to obtain a sintered body; blowing the sintered body through nitrogen to remove impurities and floating powder on the surface of the sintered body; the blown sintered body is cleaned through an ultrasonic overflow method, and the cleaned sintered body is dried; and carrying out secondary sintering on the dried sintered body in a hydrogen atmosphere to obtain the porous tungsten filter element. The high-quality porous tungsten filtering element which is high in purity, cleanliness and strength, low in oxygen content and uniform in pore diameter distribution can be prepared.

The invention belongs to the field of foamed ceramics, and particularly relates to a whole-body ion-colored foamed ceramic as well as a preparation method and application thereof. The foamed ceramic is prepared from the following raw materials in percentage by mass: 40 to 70 percent of lithium tail mud, 0 to 16 percent of foamed ceramic waste powder, 0 to 6 percent of foamed ceramic cutting material (black), 3 to 20 percent of magnesia soil, 12 to 22 percent of foamed ceramic cutting material (white), 0.1 to 0.8 percent of silicon carbide and 0.1 to 15 percent of coloring agent. The coloring agent is a metal oxide. The foaming ceramic obtained by selecting proper main body raw materials and sintering is good in compression resistance and breaking strength, the whole body is colored and uniform in color development, meanwhile, the raw materials mainly adopt the lithium tailings and solid waste generated by ceramic processing, the production cost can be effectively reduced, waste recycling is achieved, and the foaming ceramic is green, environmentally friendly and eco-friendly, and is suitable for industrial production. The method is suitable for building exterior wall decoration and ancient building restoration.

The invention relates to the technical field of medical inspection equipment, in particular to a suction filtration device for CTC enrichment staining, which comprises a fixing assembly and a micro-fluidic chip mounted on the fixing assembly, the micro-fluidic chip comprises a reagent groove and a rigid chip fixing sheet arranged at the lower end of the reagent groove, the rigid chip fixing sheet is provided with a first through hole, and a second through hole is formed in the rigid chip fixing sheet. A chip body is placed in the first through hole, the reagent groove is of a sheet structure with a liquid leakage hole longitudinally penetrating through the body of the reagent groove, and a liquid suction assembly is arranged on the lower surface of the rigid chip fixing sheet. The suction filtration device adopts a rigid chip which is uniform in aperture and less in filtrate residue, so that the phenomenon of cell stacking or hardening caused by overlarge negative pressure during suction filtration can be effectively avoided, and the quality of cell enrichment and dyeing is improved; residual reagents in the chip can be removed by swinging and inclining the fixing assembly, so that automatic operation can be conveniently realized.

The invention discloses a method for synthesizing silica sol by adopting a loop reactor and a method for synthesizing silicon dioxide. The vacuum suction feeding mode of the Venturi jet mixer in the loop reactor is adopted, and the system has the advantages that no return gas exists, the blockage and corrosion phenomena caused by return gas of the raw material silicon tetrachloride and the by-product hydrogen chloride are avoided, and the system can stably run for a long time. Compared with the problem of product agglomeration caused by violent reaction, mass transfer and untimely mixing of silicon tetrachloride liquid-phase hydrolysis in a traditional tank reactor, high-speed water flow shears sucked gaseous silicon tetrachloride into fine bubbles and forms turbulent flow, the gas-liquid mixing effect is enhanced, the water amount at the two-phase mixing position is always excessive, and the reaction time is shortened. The problem that the concentration of local silicic acid is too high to cause polycondensation to generate agglomerates is avoided, and homogeneous silica sol can be obtained. The yield of silicon dioxide is greater than 93% and is far greater than the yield in a traditional tank reactor.

The present application relates to the field of polymer thermal insulation materials, and specifically discloses a fully water-foamed polyurethane for thermal insulation pipes and a preparation method thereof. The raw materials used for polyurethane include black material and white material, wherein the black material is polymethyl polyphenyl polyisocyanate, and the white material includes polyether polyol A-E, a catalyst, a foam stabilizer and water; its preparation method is: S1. All components in the white material are mixed evenly to obtain a mixture; S2. Under the conditions of a temperature of 15-35°C and a rotation speed of 2500-2600r / min, the mixture is mixed and stirred evenly with the black material to obtain polyurethane foam. The polyurethane foam of the present application uses water as a foaming agent, is green and environmentally friendly, has a low odor during the foaming process, and has high mechanical properties, and is not easy to burn the core and crack.

The invention belongs to the field of medical materials, and particularly relates to a high-imbibition polyvinyl formal hemostatic sponge and a preparation method thereof. The preparation method comprises the following steps: preparing a polyvinyl alcohol solution, adding starch to prepare a premixed solution, then adding a cross-linking agent, a foaming agent, a catalyst and a surfactant, fully mixing, then putting into a drying oven for curing, then cleaning the materials, freeze-drying, and carrying out irradiation sterilization to obtain the high-imbibition polyvinyl formal hemostatic sponge. The sponge prepared by the invention has high expansibility and high water absorbability, and achieves the purpose of reducing the cost by reducing the material and reaction time while ensuring excellent physical and chemical properties and biological properties. The prepared polyvinyl formal sponge is mainly applied to surgical operations, wound first aid, cavity hemostasis and the like.

The embodiment of the invention provides a pantograph slide plate manufacturing method which comprises the following steps: S1, mixing a high-purity carbon material, asphalt, copper powder and titanium carbide, and then adding a binder to form a five-component mixture; wherein the titanium carbide is used as a doping agent; s2, pressing and pre-shaping the five-component mixture, and then performing prefabricated graphitization sintering to obtain the pantograph carbon-based electric contact material, and S3, the surface of the pantograph carbon-based electric contact material obtained through graphitization sintering treatment is subjected to treatment and conformal processing to form a carbon strip, the carbon strip is embedded into the titanium pantograph type, and the titanium lightweight high-speed rail pantograph slide plate is obtained. According to the embodiment of the invention, the technical problem of non-uniform guiding performance of the pantograph slide plate manufactured by a traditional manufacturing method of the pantograph slide plate is solved.

The invention belongs to the technical field of silicon micro-powder, and particularly discloses silicon micro-powder for integrated circuit packaging and a preparation method thereof, the silicon micro-powder is multi-stage modified spherical silicon micro-powder, and the multi-stage modified spherical silicon micro-powder is prepared from basic spherical silicon micro-powder through modification processes of gradient alkali etching pore forming, bifunctional silane grafting and polyaryletherketone oligomer coating in sequence; in the basic powder purification step, precise purification of the industrial-grade silica powder is realized through a combined process of acid pickling, hydrofluoric acid shallow etching, water washing and drying. Wherein the diluted hydrochloric acid can remove metal cation impurities in the silica powder in a targeted manner, and the impurities are prevented from forming a conductive path in the subsequent packaging process, so that the dielectric loss is reduced, and the insulating property of the material is improved; and the shallow etching of the hydrofluoric acid dilute solution can peel off the surface silicon dioxide impurity layer, and meanwhile, the etching depth is controlled to avoid damaging the spherical structure of the silicon micro powder, so that the uniformity of the subsequent modification process is ensured, and a high-quality base material foundation is laid for the subsequent modification step.

This invention relates to the field of dialysis paper technology, and particularly to a fiber pretreatment method for dialysis paper and dialysis paper itself. The fiber pretreatment method for dialysis paper includes the following steps: Step 1, weighing softwood fibers, broadwood fibers, and regenerated fibers and placing them in deionized water, stirring thoroughly to obtain a mixture; Step 2, adding an initiator to the mixture, heating to 35-45°C, and mixing evenly; Step 3, adding modified nanoparticles to the mixture from Step 2, and stirring continuously for 4-6 hours; Step 4, after the reaction is complete, washing, filtering, and drying to obtain the pretreated fibers for dialysis paper. The fiber pretreatment method for dialysis paper proposed in this invention can uniformly attach nanoparticles to the fiber surface. When the nanoparticles are compressed by the fibers, they can aggregate towards the "gaps" between the fibers, preventing excessively large gaps between the fibers and avoiding the passage of bacteria or dust through the dialysis paper.

The application relates to the technical field of biomedical materials, and specifically discloses a preparation method of a double-crosslinked 3D-printed bone repair scaffold. The scaffold is made of a biphasic calcium phosphate matrix and a gelatin methacrylate hydrogel outer layer. The preparation method comprises the following steps: firstly, preparing biphasic calcium phosphate ink, and constructing a porous scaffold blank through 3D printing; then, carrying out double-crosslinking treatment of calcium chloride solution and glutaraldehyde solution in sequence to obtain a scaffold matrix with enhanced mechanical properties; then, preparing gelatin methacrylate hydrogel loaded with modified teriparatide, and compounding the gelatin methacrylate hydrogel with the scaffold matrix; and finally, obtaining the final product after blue light crosslinking and solidification. The bone repair scaffold has good biocompatibility and osteogenic activity, and can effectively promote bone defect repair. In addition, the preparation method is controllable and has good repeatability, the structure of the scaffold is accurately controlled through the 3D printing technology, and a new approach is provided for the preparation of personalized bone repair materials.

The invention relates to the technical field of polymer foam materials, in particular to a low-density large-size polyimide foam material and a preparation method thereof. According to the invention, aromatic dianhydride, a polar solvent and low-molecular alcohol are used as reaction raw materials, an initiator, a catalyst, a surfactant, a foaming agent, isocyanate and a curing agent are used as auxiliary materials for foaming, then heating is carried out by a drying oven for shaping, and then drying is carried out to obtain the product. The preparation process is simple, the manufacturing cost is low, polyimide is low in density and large in size, industrial production is easy, and the prepared polyimide foam material has the advantages of being low in heat conductivity coefficient, excellent in flame retardant property, small in moisture absorption rate, good in corrosion resistance, resistant to smoke, resistant to mildew, good in sound absorption and the like.