1055results about How to "Uniform pore size distribution" patented technology

The present invention belongs to the field of porous ceramic material technology, and is the preparation process of one low cost and high performance porous silicon nitride/silicon carbide ceramic. The preparation process includes compounding material, forming and sintering as the conventional ceramic material preparing steps. It features that phenolic resin used as pore creating agent and carbon source is in-situ produced into SiC phase through the carbon hot reduction during sintering; and that Si3N4, Al2O3, Y2O3 and phenolic resin in certain proportion are produced into slurry through adding anhydrous alcohol and mixing for 12-24 hr and stoved into powder; and that the ceramic powder is processed through formation, cracking to eliminate glue, carbon hot reduction and sintering to produce the porous ceramic material with porosity of 40-70 %, strength of 70-160 MPa and low cost.

Porous poly(aryl ether ketone) (PAEK) articles are prepared from PAEK/polyimide blends by selective chemical decomposition and subsequent removal of the polyimide phase. Porous PAEK articles exhibit highly interconnected pore structure and a narrow pore size distribution. The porous PAEK articles of the present invention can be utilized as a porous media for a broad range of applications, including membranes for fluid separations, such as microfiltration, ultrafiltration, nanofiltration, and as a sorption media.

The invention discloses a method for preparing silicon nitride porous ceramic by a gel mold injection method. The method comprises slurry preparation, blank preparation and degreasing and sintering of the blank to obtain the silicon nitride porous ceramic with porosity ranging from 49 to 63 percent, buckling strength ranging from 54 to 234MPa and pore-size distribution ranging from 0.1 to 1.0 mum. The method can prepare the silicon nitride porous ceramic with high performance and high strength only by utilizing numerous gel micromolecules formed by organic monomer solidification in a high temperature oxidation decomposition process. The porous ceramic prepared by the method has fine pores and narrow pore-size distribution. Meanwhile, the method can prepare porous ceramic products with large size and complicated shape.

Disclosed are a separator for lithium ion secondary batteries, having an inorganic layer formed from inorganic particles, characterized in that the inorganic particles have a particle diameter distribution in which the 50% cumulative particle diameter D₅₀ is in the range of 100 nm to 500 nm, the 10% cumulative particle diameter D₁₀ is 0.5D₅₀ or more, and the 90% cumulative particle diameter D₉₀ is 2D₅₀ or less; a method for manufacturing the separator; and a lithium ion secondary battery using the separator. When the separator is used, there can be produced a lithium ion secondary battery in which a short circuit caused by contraction or melting can be definitely prevented, as well as the current density applied to the electrodes during charging and discharging is uniform so that charging and discharging can be efficiently achieved.

The invention provides a preparation method of high-purity collagen protein sponge, and relates to a preparation method of collagen protein sponge. The preparation method of the high-purity collagen protein sponge is used for solving the problems that the collagen protein sponge prepared by using a conventional method is long in production cycle and low in yield and purity and has poor hemostasis performance. The preparation method of the high-purity collagen protein sponge comprises the following steps: step one. pretreating fresh bovine heel tendons; step two. extracting collagen protein; step three. centrifuging; step four. salting out; step five. dissolving; step six. carrying out gradient dialysis; step seven. pre-freezing; step eight. carrying out freeze drying; and step nine. sterilizing. The final product prepared by using the method has a smooth and flat surface and relatively good hemostatic performance and is uniform in pore size distribution. The product has relatively high purity (the total amount of amino acids reaches 97.73%), an obvious hemostatic effect and no abnormal taste, is safe, non-toxic, high in yield and short in time; liquid is clear without impurities; the production cycle is shortened; the whole preparation process is carried out at a room temperature; the biological activity of the collagen protein is maintained; and the application of the high-purity collagen protein sponge in clinical is improved.

The invention discloses a polypropylene hollow fiber microporous membrane and a preparation method thereof. The hollow fiber microporous membrane comprises the following components in percentage by weight: 15-45% of polypropylene, 50-80% of thinner and 0.1-5% of additive. The preparation method of the hollow fiber microporous membrane is realized on the basis of a thermotropic phase separation process. The preparation method of the polypropylene hollow fiber microporous membrane is simple and easy to industrialize, and has low requirements on equipment, the prepared hollow fiber microporous membrane has the advantages of high strength, uniform pore diameter distribution, high porosity and the like, the pore diameter of the hollow fiber microporous membrane can be controlled between 0.1 and 0.45mu m, and the porosity is 60-85%, so the hollow fiber microporous membrane has large water flux, is not easy to block in use, can be widely used for feeding water treatment, and is particularly suitable for the membrane bioreactor technology and other water treatment fields.

The invention relates to a silicon carbide ceramic support body and a preparation method thereof. The raw material powder of the support body is mixed powder consisting of silicon carbide powder 1 and silicon carbide powder 2, wherein the silicon carbide powder 1 has a median particle diameter D50 of 25-45mu m, the silicon carbide powder 2 has a median particle diameter D50 of less than 5mu m, the ratio of the D50 of the silicon carbide powder 1 to the D50 of the silicon carbide powder 2 is not less than 6, and the consumption of the silicon carbide powder 2 is 0.5-13 percent of the weight of the used silicon carbide powder 1. The raw material powder is mixed with a solvent, an adhering agent, a plasticizer and a pore-forming agent to form pug, the pug is subjected to stamping to form a raw blank, the raw blank is dewatered and degreased to form a calcined product, and the calcined product is sintered in argon or hydrogen atmosphere or vacuum to form the support body of a recrystallized silicon carbide ceramic membrane. The support body of the recrystallized silicon carbide ceramic membrane has filtering flux and strength which are higher than those of the traditional commercial support body of an aluminum oxide ceramic membrane.

The invention provides a preparation method of an S/TiO2 composite material for an anode of a sodium-sulfur battery. The preparation method comprises the following steps: dissolving butyl titanate, a template agent and a hydrolysis inhibitor into absolute ethyl alcohol; adding a mixed solution of de-ionized water and the absolute ethyl alcohol to form semi-transparent sol; transferring the sol into a high-pressure reaction kettle to react; calcining a solid product in air to remove the template agent to obtain meso-porous titanium dioxide; dispersing the meso-porous titanium dioxide into a sodium thiosulfate solution dissolved with a surfactant; adding hydrochloric acid to react; washing the solid product by a lot of the de-ionized water and drying; and eating under the protection of an inert atmosphere to obtain the S/TiO2 composite material. The meso-porous titanium dioxide prepared by the preparation method is large in specific surface area, high in porosity and strong in adsorption capability; the electrical conductivity of sulfur can be improved and a lot of nano sulfur and polysulfide can be contained; the polysulfide can be effectively prevented from being dissolved and diffused in electrolyte, and the utilization rate of the sulfur is improved; meanwhile, the structure of the meso-porous titanium dioxide is stable and a pore channel cannot be easily damaged, so as to have buffering effects on volume expansion and retraction in a charging/discharging process of a sulfur electrode.

The invention belongs to the field of high-performance carbon materials, and particularly relates to a preparation method of low-cost porous graphene. A low-cost carbon precursor and additives are adopted as raw materials, the raw materials are mixed, and low-temperature carbonization and pickling technology are adopted to prepare the porous graphene. The method has the advantages that the technology is simple, the cost is low, and industrialization popularization is easy; the obtained porous graphite is high in purity, the number of structural defects is small, and pore size distribution in uniform.

The invention relates to technology for preparing an anodized aluminum oxide film, in particular to a method for preparing a pore diameter controllable through hole anodized aluminum oxide film. The method comprises the following steps of: performing anode electrolysis treatment on an anodized aluminum oxide film with an aluminum substrate in mixed solution of perchloric acid and acetone to obtain a pore diameter controllable anodized aluminum oxide film with two open ends in short time (2-300 seconds), wherein the pore diameters at the top end and the bottom end fo the anodized aluminum oxide film are accurately controllable in ranges of between 10 and 100nm and between 5 and 25nm; and putting the aluminum oxide film with the aluminum substrate subjected to stage depressurization-method oxidation into acetone solution of perchloric acid, and applying voltage 5-15V higher than film forming voltage for anode electrolysis treatment to obtain the pore diameter controllable through hole anodized aluminum oxide film. In the method, the pore diameters at the top end and the bottom end of the anodized aluminum oxide film can be respectively controlled, holing and removal of the aluminum substrate are completed by one step, and a plurality of problems of complicated process, time consumption, difficult control of pore diameters and the like in the conventional process for preparing the through hole anodized aluminum oxide film.

The invention discloses a method for preparing silicon-aluminum aerogel by using fly ash as a raw material through normal pressure drying, which comprises the following steps of: mixing, grinding and calcining the fly ash and sodium carbonate to enable acidic oxides and amphoteric oxides in the fly ash to react with the sodium carbonate, then dissolving a sintered material with hydrochloric acid, and carrying out suction filtration to obtain a filtrate, i.e. silicon-aluminum sol; settling and aging the silicon-aluminum sol to form silicon-aluminum gel; soaking with circulating water to remove chloride ions; soaking with an ethanol solvent instead of water; soaking with an organosilicon compound as a surface hydrophobic agent for surface hydrophobic treatment; and preparing the silicon-aluminum aerogel through normal pressure drying. The invention uses the industrial waste fly ash as the raw material to replace an organosilicon source with high price and a certain toxicity, and uses normal pressure drying to replace supercritical drying, so the safety performance is greatly enhanced, the production cost is greatly lowered; and the method has simple process and convenient operation and is suitable for large-scale production. The prepared silicon-aluminum aerogel can be widely applied to the fields of heat insulating materials and the like.

The invention discloses a magnetic PAFs solid-phase extracting agent. A preparation method of the magnetic PAFs solid-phase extracting agent includes allowing 3-aminopropyl triethoxy silylation ferroferric oxide to have a temperature-programmed reaction with piperazine and cyanuric chloride in the presence of N, N-diisopropylethylamine to obtain the magnetic PAFs solid-phase extracting agent. The magnetic PAFs solid-phase extracting agent and the preparation method thereof have the advantages that the prepared magnetic PAFs solid-phase extracting agent is good in dispersity and stable in core-shell structure; the preparation method is simple, low in cost, widely applicable, capable of achieving repeated material recycling, and the like; a covalent organic framework bonded to the ferroferric oxide can provide various action sites such as an inclusion interaction site, a hydrogen-bond interaction site, a pi-pi interaction site and an anion exchange site, so that the covalent organic framework has specific recognition and retention acting force on polar substances such as phenols and carboxylic acids.

The invention belongs to the field of preparation of nano porous metal materials, and relates to a method for preparing nano porous silver based on an Ag-based amorphous alloy. By the method, the nano porous silver with the aperture of 20-100 nm is finally obtained by preparing a series of Ag-Mg-Ca amorphous alloy thin bands by taking the Ag-based amorphous alloy as a precursor by a solvent quick quenching method and then removing Mg and Ca elements by performing electric chemical alloy component corrosion removal by proper electrolyte. By the method, the structure and the size of the nano porous silver are adjusted and controlled by controlling the amorphous alloy components or electric chemical corrosion temperature; the operation technology is simple; and furthermore, the nano porous silver is extremely high in surface-enhancement raman scattering (SERS) performance and has a wide application prospect in the fields of environment friendliness, catalysis and biological sensors.

The invention discloses a preparation method of porous geological polymer microspheres. The porous geological polymer microspheres are prepared by a dispersion suspension solidification method. Compared with the prior art, low-temperature curing and one-shot molding granulation are realized without requirements of high-temperature calcination and curing and addition of other auxiliaries; and at the same time, large-scale use of solid wastes is realized, and raw materials are widely available, cost is low, process is simple, and the whole process is non-toxic and pollution-free; in addition, the preparation efficiency is high with a ball-forming degree exceeding 90%; the size of the particles can be adjusted, and the pore size distribution is uniform; the pore volume is large, and can be regulated, and a specific surface area of the microspheres reaches 110m2/g, thus, the porous geological polymer microspheres can be directly used for packed columns for column separation. Experiments show that the porous geological polymer microspheres have a good adsorption effect on heavy metals, and can be used as adsorbents for heavy metals, and have a broad application prospect in the aspect ofremoving heavy metals and radioactive elements in water.

The invention discloses a synthetic method for an ordered mesoporous nanocrystal titanium/carbon dioxide composite material with high content of titanium dioxide. Resol with the molecular weight of 200 to 500, triblock copolymer and mixed titanium source form an ordered mesophase in a highly volatile organic solvent system by self assembly induced by solvent volatilization and then the ordered mesoporous nanocrystal titanium/carbon dioxide composite material is obtained after calcination in nitrogen atmosphere. The composite material prepared has ordered pore canal structure, high specific surface which is 100 to 400m<2>/g, large pore volume which is 0.1 to 0.5cm<3>/g and even aperture which is about 2.3 to 5.0nm. The synthetic method overcomes the disadvantages that the specific surface of titanium dioxide is low and the pore canal structure is easy to collapse during the course of crystallization, successfully introduces carbon component to obtain the ordered mesoporous nanocrystal titanium/carbon dioxide composite material and has the advantages of simple synthetic operation, cheap raw material price and low device requirement.

The present invention relates to one kind of alumina-magnesia refractory brick containing light porous aggregate and its production process. The technological scheme is that the alumina-silica refractory brick is produced with light porous Al2O3-MgO refractory material 30-70 wt%, compact Al2O3-MgO refractory material 0-35 wt%, fine magnesia powder 5-30 wt%, fine alpha-Al2O3 powder 3-10 wt%, fine corundum powder 0-25 wt% and fine spinel powder 0-25 wt%, and through mixture, adding waste pulp liquid in 3-7 wt% as binding agent, stirring, pressing to form adobe, drying at 100-150 deg.c for 12-48 hr, sintering at 1400-1600 deg.c for 2-5 hr and naturally cooling. The alumina-magnesia refractory brick has high macro porosity, small average pore size, low heat conductivity and high medium erosion resistance, and may be used in the permanent layer or work layer in high temperature kiln, furnace and container.

The invention belongs to the field of aerogel material preparation technologies, and relates to a method for preparing a hydrophobic SiO2 aerogel by virtue of normal pressure drying. During the preparation, a two-step method is adopted, an organic silicon source as precursor, water as a hydrolysis agent, absolute ethyl alcohol as a solvent, acid and alkali as catalysts, and an organic silicon solution and a surface modifier. The preparation method comprises the following steps: mixing and stirring the organic silicon source, the water and the absolute ethyl alcohol in proportion, and respectively adding an acid catalyst and an alkaline catalyst by virtue of an acid and alkali two-step method to regulate pH value so as to form gel; performing solvent replacement on the aged gel, carrying out surface hydrophobic modification, replacing a hydrophilic group on the surface of the gel through a hydrophobic group, so that the gel is hydrophobic; finally, performing normal pressure drying to obtain the hydrophobic SiO2 aerogel. The method disclosed by the invention can be used for reducing the preparation cost of the aerogel; moreover, according to a hydrophobicity test, the contact angle can reach about 158 degrees, thereby showing that the hydrophobicity is good.

The invention provides a method of preparing a hemp activated carbon fiber, which adopts a hemp fiber or a hemp fabric as the raw material. The method includes the following steps: firstly, the hemp fiber or the hemp fabric is boiled in a pretreating solution, taken out and then dried; secondly, the obtained fiber or hemp fabric is put into a charing furnace, heated for charing under the protection of the nitrogen gas, then cooled to the room temperature and then rinsed repeatedly to be neutral; and thirdly, vapor is entered into the hemp fiber or the hemp fabric for an activation treatment, then dried after the activation treatment and finally a hemp activated carbon fiber is obtained. The specific surface area of the prepared activated carbon fiber is 680-1950m<2>/g and the yield of the activated carbon fiber is 20 to 62 percent.

The nonwoven fabric sheet of the present invention is characterized by a porosity in the range of 0.3 to 0.7 and an average pore size in the range of 0.5 μm to 5.0 μm. The nonwoven fabric sheet of the present invention preferably has a maximum pore size (μm)/average pore size (μm) ratio of 1.30 or lower. The nonwoven fabric sheet of the present invention is obtained by press-molding a nonwoven fabric at a temperature lower than the melting point of the thermoplastic resin which constitutes the nonwoven fabric sheet. According to the present invention, there is provided a nonwoven fabric sheet that has a high porosity, small uniform pore sizes and excellent productivity, which can suitably be used in various applications such as filters, light diffusing material, liquid absorber and heat insulating materials; and a method for producing the nonwoven fabric sheet.