1260results about How to "Uniform pore size" patented technology

The invention discloses a preparation method of polytetrafluoroethylene superfine fiber porous membrane. In the method, high concentration polytetrafluoroethylene aqueous emulsion is mixed with matrix polymer uniformly to prepare spinning solution. With the effect of high voltage electric field, polytetrafluoroethylene/matrix polymer composite superfine fiber porous membrane with the diameter of 100 nm to 2 [mu]m is obtained by electrostatic spinning, and then polytetrafluoroethylene superfine fiber porous membrane is formed at the conditions of sintering temperature being 330 to 500 DEG C and the sintering time lasting 30s to 5min so that the aperture diameter is 100 nm to 10 [mu]m and the porosity is 50% to 80%. The polytetrafluoroethylene superfine fiber porous membrane prepared by using the method has uniform aperture diameter and high porosity, and can be widely applied to filter material. Compared with the existing technology, the preparation method has the characteristics of simple processing technology, short process and low cost.

Engineered structure for charge storage. An electrolyte is disposed between two electrically conducting plates, each plate serving as a base for an aligned array of electrically conducting nanostructures extending from the surface of each plate into the electrolyte. The nanostructures have diameter and spacing comparable to the dimension of an ion of the electrolyte. An electrically insulating separator is disposed between the two plates. A CVD process (or other processes yielding similar results) is used to make the aligned array of electrically conducting nanostructures.

The invention discloses polyimide foam and a preparation method thereof. Aromatic dianhydride and/or aromatic acid ester, alcohol with low molecular, a catalyst and a surface active agent are mixed proportionally in a polar solvent and react so as to form foam precursor solution. The foam precursor solution and isocyanate react in a mould and freely foam into a foam intermediate. The intermediate is solidified by microwave radiation or/and oven heating to obtain solid polyimide foam. The preparation process has short path, simple technology, good stability for storage of the foam precursor solution, adaptation to processing technologies of pouring, spray coating, extrusion, and the like, no occurrence of defects of cracked foam, foam combination, subsidence and incomplete amination, low preparation cost as well as uniform hold diameter and stable performance of the solid polyimide form, and is convenient for popularization and application.

The invention discloses a lithium-ion battery diaphragm. The lithium-ion battery diaphragm is prepared by coating the upper surface and the lower surface of a porous base material with one or more porous coatings, wherein the thickness of the porous base material is 4-80 microns; the porosity of the porous base material is 30%-90%; and each porous coating comprises the following raw materials in parts by weight: 30-100 parts of a polymer material, 0-70 parts of inorganic powder and a surface treating agent and 0-50 parts of a compatibilizer. The invention further discloses a preparation method of the lithium-ion battery diaphragm. The battery diaphragm disclosed by the invention is controllable in pore size and porosity and uniform in pore size; the finished diaphragm product is high in high-grade rate, good in wettability and high in safety; and the diaphragm is good in heat resistance, and has a thermal closing function.

The invention relates to a composite stacked and coated lithium ion battery diaphragm and a preparation method thereof. The diaphragm is a porous diaphragm which is prepared by mixing one or many kinds of coating sizing agents and is provided with a layer or multiple layers of structures; the porous diaphragm comprises the following components in parts by weight: 30-100 parts of a polymeric material, 0-70 parts of inorganic powder bodies and a surface treating agent thereof, and 0-50 parts of a compatibilizer; the polymeric material at least selects and uses two kinds of polymeric materials, one kind of the polymeric materials is a thermoplastic material of which the melting point or the viscous flow temperature is 100-150 DEG C, and the other kind of the polymeric materials is a thermoplastic material or a thermosetting material of which the melting point or the viscous flow temperature is higher than or equivalent to that of the thermoplastic material of which the melting point or the viscous flow temperature is 100-150 DEG C. The composite stacked and coated lithium ion battery diaphragm provided by the invention is uniform in bore diameter, good in wettability, favorable in heat resistance and good in hot melting and closing function, and the preparation method for the composite stacked and coated lithium ion battery diaphragm is simple in technology, wide in the material selecting range, and controllable in the micropore forming condition.

The invention discloses a polyvinyl alcohol-polyurethane elastic buffing wheel and a preparation method of the polyvinyl alcohol-polyurethane elastic buffing wheel. The preparation method comprises the steps that firstly, polyvinyl alcohol is mixed with distilled water, and the mixture is dissolved for 20-30 minutes under the condition of 50-95 DEG C water bath and at the rotation speed of 400-600r/min to obtain a polyvinyl alcohol aqueous solution; then, the polyvinyl alcohol aqueous solution is heated up to 30-100 DEG C, grinding materials are firstly added into the polyvinyl alcohol aqueous solution, after the mixture of the grinding materials and the polyvinyl alcohol aqueous solution is stirred and mixed evenly at the rotation speed of 400-600r/min, polyurethane pre-polymers, catalysts and air hole generating agents are added, and all the components are stirred and mixed evenly at the rotation speed of 400-600r/min and react for 5-10min; solidification is conducted for 2-4h under the condition of 30-100 DEG C, and then the buffing wheel which is good in elasticity, good in water resistance, good in heat-dissipating performance and high in mechanical strength is obtained. The elastic buffing wheel is even in foam hole, good in abrasion resistance and grinding force, not prone to deforming or curling in humid environment and applicable to long-time grinding work.

The invention discloses a preparation method of medical porous titanium and titanium alloy, which comprises the following steps: proportionally preparing titanium powder, alloy element powder and pore forming agent powder according to needs; carrying out ball milling, mixing and mechanical pressing by a powder metallurgy blank making technique to obtain a blank; putting the blank in a thermal insulation barrel, and putting the thermal insulation barrel into a microwave sintering furnace; and after vacuumizing the furnace chamber to a vacuum degree of 0.1Pa, charging argon with the purity of 99.999% to form cyclic protection, controlling the output power of the microwave sintering furnace at 0.5-3kW, heating to the sintering temperature of 800-1200 DEG C at the heating rate of 5-40 DEG C/minute, keeping the temperature for 5-30 minutes, shutting down the microwave source, and carrying out furnace cooling to obtain the medical porous titanium and titanium alloy. The invention has the advantages of simple preparation method, short sintering period, high efficiency, low sintering temperature and low energy consumption; and the sintered porous titanium and titanium alloy have excellent mechanical properties, and can be used as alternate repair material for bones, joints, artificial radix dentis and other hard tissues.

The invention relates to dual-hole polysaccharide microspheres, a preparation method and a purpose thereof. The microspheres are formed by a plurality of stacked polysaccharide particles with small particle sizes, with an average particle size of the microspheres being 500 nm to 500 [mu]m; and comprises gel pores containing the polysaccharide as well as macroporous dual-hole structure formed by gaps among the polysaccharide particles. The preparation method of the microspheres comprises dispersing the polysaccharide particles in a water phase and then in an oil phase to form water in oil emulsion, heating the emulsion, and stirring to obtain the dual-hole polysaccharide microspheres. Furthermore, according to the preparation method, together with a membrane emulsification technology, the dual-hole polysaccharide microspheres with uniform particle size distribution can be prepared, with an average particle size range being 500 nm to 100 [mu]m and a particle size distribution coefficient being less than 20 %. The dual-hole polysaccharide microspheres provided by the invention are suitable for being used as separation mediums for separating biomacromolecules, biologically active material carriers, etc.

An adsorbent for exhaust gas purification is composed of a molecular sieve having high acidic hydrothermal resistance obtained by substituting part or the whole of the Al constituting the framework of crystalline aluminosilicate molecular sieve, with the ion of at least one element selected from elements M for framework element substitution, i.e. Mg, P, Ti, Cr, Ge, Zr, In, Sn, Hf, W, V, Co, Ni, Cu, Zn, Ag and B. The adsorbent for exhaust gas purification can be suitably used in the applications requiring high heat resistance and high hydrothermal resistance, such as the exhaust gas purification system for internal combustion engine or combustion furnace. The adsorbent can be used particularly preferably for the purification of automobile exhaust gas containing hydrocarbons, nitrogen oxides, etc.

The invention relates to an asymmetrically-structural ceramic ultrafiltration membrane and a preparation method thereof, wherein the preparation method thereof comprises the steps: dispersing one-dimensional fibrous material in sol and sufficiently mixing the material with the gel; by adding deionized water, controlling the weight ratio of gel particle to fiber in membrane preparing solution in a range from 0.01 to 0.4, adjusting pH value of the solution, adding dispersing agent, thickening agent and defoaming agent to formulate the membrane preparing solution, coating membrane on a porous support body and drying the porous support body to form a transition layer; coating the gel-containing membrane preparing solution on the surface of the transition layer, air-drying, oven-drying and roasting the wet membrane, and naturally cooling the membrane to result in the asymmetrically-structural ceramic ultrafiltration membrane. Since the transition layer is composed of fiber and sintering is promoted through the gel, resistance of the transition layer is advantageously lessened and interior combination strength of the transition layer is enhanced; the fiber-constructed transition layer divides large pores into small pores to provide larger total porosity and flowing pore channel, thus high permeation flux is maintained while high selectivity is obtained.

The invention relates to a process and an apparatus for continuous production of a closed-cell aluminum foam through blowing foaming. The process comprises the following steps: melting a raw material, adding with a ceramic tackifier and a moistening promoter, stirring to obtain molten aluminum with uniform component, carrying out continuous foaming with the apparatus for the continuous productionof the closed-cell aluminum foam with blowing foaming to obtain a molten aluminum foam with uniform foam size, and controllable density and productivity, and producing a foamed aluminum board by going through a net belt and transmitting with an arc transition mechanism and cutting. The apparatus is characterized in that: a simple crank link mechanism is adopted to realize the reciprocating motion of a horizontal outlet duct, and the arc transition mechanism allows the ascending lifting of the molten aluminum foam to be changed into horizontal transmission. According to the invention, the process and the apparatus are simple, the operation control is accurate, and a purpose that the pore size and the density of foamed aluminum products can be accurately controlled at a high efficiency anda low cost is realized because the foam size of the molten aluminum is adjusted by changing the frequency of the reciprocating motion of the outlet duct, the pressure and the flow of a compressed gasand the diameter of outlet micropores.

The invention discloses modified polyimide foam and a preparation method thereof. The preparation method comprises the following steps: aromatic dianhydride and/or aromatic acid ester, siloxane with active terminal group, low molecular alcohol, a catalyst and a surface active agent are mixed into a polar solvent according to proportion and react to form foaming precursor solution which reacts with isocyanate to form foaming intermediate solution; and the foaming intermediate solution carries out foaming freely in a mold and forms a modified foaming intermediate which is radiated by microwave or/and heated and cured in an oven, and then the solid polyimide foam is obtained. The method has short route of preparation process and simple technique; the foaming precursor solution has good stability of storage, is suitable for the processing techniques of casting, painting, extruding and the like, and the defects of broken foam, parallel foam, depression and incomplete imidizate of materials do not occur; the polyimide foam has even aperture, high stability, low rigidity, good flexibility and good processability; and the preparation cost is low, thus being convenient to promotion and application.

The invention discloses mesoporous silica with a yolk-shell structure and a preparation method thereof. The morphology of the mesoporous silica is of spherical bodies. The spherical body has a mesoporous core and a mesoporous shell. A cavity structure is between the mesoporous core and the mesoporous shell. Mesoporous silica balls have high specific surface area, uniform and adjustable particle size and uniform pore size. The preparation method of the mesoporous silica includes: dissolving a surface active agent in a mixed solution of ethanol, ammonia and water, adding two silica precursors into the mixed solution under heating and stirring conditions, transferring the obtained spherical silica into water after reacting for a period, etching to remove intermediate loose layers of silica balls, finally removing the surface active agent to obtain mesoporous silica products having the yolk-shell structure. The preparation method of the present invention has the characteristics of simple process, low cost, and environmental protection. The prepared mesoporous silica has great application potential in medical imaging, drug delivery and other fields.

The invention provides heat stable aqueous solutions or gels comprising a biologically active protein and a stabilizing effective amount of a mixture of a polysaccharide and an amino acid based compound. The invention also discloses stabilized solutions or gels suitable for use in an implantable drug delivery device at body temperature, and a device containing the stabilized solution or gels.

The present invention belongs to the field of biomedical material technology, and is especially one kind of mesoporous biological glass fiber material with bone repairing bioactivity and its preparation process. The mesoporous biological glass fiber material is prepared through spraying sol in controlled viscosity by means of template of surfactant. It has controllable composition, has the main components of SiO2, CaO and P2O5 and may have also TiO2, MgO, etc. added. It has controllable mesoporous structure of pore size 1-30 nm, specific surface area 100-1000 sq m/g, pore volume 0.3-1.5 cu cm/g. It possesses controllable macroscopic fiber shape, excellent osteogenesis activity and cell activity, and excellent biocompatibility and degrading performance. Therefore, the mesoporous biological glass fiber material may be used as bone repairing filler material and rack material.

The invention discloses a preparation method of ordered mesoporous silica microspheres with hollow structures. The preparation method comprises the following steps: firstly, dissolving a cationic surface active agent in mixed solution of ethanol and water, sequentially adding ammonia water and a silicon source in the mixed solution under the conditions of heating and mixing, and reacting for a period of time to obtain solid silica microspheres; washing the obtained silica, transferring the silica into water for etching, and reacting for a period of time to obtain hollow silica microspheres; and finally, collecting the hollow silica, and obtaining products of ordered mesoporous silica microspheres with hollow structures by drying and roasting. In the preparation method, a sacrificial hard template or an emulsion template does not need to be prepared in advance. The preparation method has the characteristics of simple technological process, mild reaction conditions, low cost, and environmental friendliness; and the prepared hollow mesoporous silica microspheres have great application potential in ultrasonic imaging, drug delivery and other biomedical fields.

The invention discloses a method for preparing a porous ceramic filter membrane by low-temperature sintering. The method comprises the following steps: mixing and stirring ceramic aggregate particles, a sintering aid, deionized water, a dispersant and a defoamer, then carrying out vacuum pressure maintaining to remove a gas in the obtained filter membrane layer slurry; soaking a support body material in the filter membrane layer slurry, then obtaining a membrane layer on the support material by a pulling method, and then sintering at 700-1070 DEG C to obtain the porous ceramic filter membrane. According to the method, the porous ceramic membrane product which is high in strength, resistant to wear and corrosion, long in life and low in cost is obtained by optimally proportioning the sintering aid, the dispersant and the defoamer, preparing the ceramic membrane layer slurry system with high stability and proper viscosity, regulating the pulling method of the ceramic support body with a high porosity and a large hole diameter in the prefabricated membrane layer slurry system, thereby obtaining a uniform and asymmetrical porous ceramic membrane blank on the whole surface of a specified position of the support body material, and finally drying stage by stage and rapidly sintering at a low temperature of 1100 DEG C so as to obtain a porous ceramic filter membrane product with high intensity, abrasion resistance, corrosion resistance, long service life and low cost.

The invention discloses a peripheral edge grinding wheel for machining PCBN (polycrystalline cubic boron nitride) blades. The peripheral edge grinding wheel comprises a grinding wheel matrix and a grinding material layer. The grinding material layer is positioned on the grinding wheel matrix and is made of raw materials including, by weight, 44-65% of diamond, 22.5-40.5% of ceramic bonding agents, 0.5-10% of pore forming agents and 5-10% of phenolic resin liquid; the ceramic bonding agents are made of raw materials including, by weight, 40-60.5% of silicon dioxide, 5.5-17% of alumina, 25-35% of boric acid, 2-7% of sodium carbonate, 8-11% of lithium hydroxide and 2-6% of calcium oxide; pore forming agents are alumina hollow balls. The peripheral edge grinding wheel has the advantages of good sharpness, high grinding quality and long service life.

Reactive prepolymers incorporating [2+2] photoreactive sites are synthesized. Upon exposure to UV light, these prepolymers undergo [2+2] cycloaddition to crosslink. When crosslinked, the reactive prepolymers form a hydrogel. Selective hydrogel formation is provided through selective exposure of the reactive prepolymer to UV light. Supports and other molecules may be attached or incorporated into the hydrogel through [2+2] cycloaddition with uncrosslinked [2+2] photoreactive sites present in the hydrogel.

The invention relates to a Titania nanometer paper and the preparation method, the key component of the Titania nanometer paper is a Titania nanometer belt or the Titania nanometer belt and additive; the Titania nanometer paper mainly includes the preparation method as follows: dispersing, filtrating and drying. Compared with the common nanometer membrane and the nanometer particle, the nanometer paper has a more predominant performance of simple making method and low cost. The nanometer paper is capable of being widely used in the aspects such as high temperature filtration, electron device and photocatalysis, etc. the invention has the advantages of rational design, simple technics, thin fibre, even aperture, good filtering quality and high temperature performance, in addition, the invention is capable of directly being cut, utilizing the average effect of the nanometer belt performance, fundamentally solving the practicality problem of the single nanometer belt device.

The invention discloses a process for preparing high porosity through hole foamed metal, which is characterized in that: the process selects a material with a foam structure as a parent material, the parent material is provided with three-dimensional through holes which are then filled with powdery slurries dissolvable in water or other solvents, the slurries are dried and hardened to form a prefabricated model, then the parent material is gasified and decomposed after calcinations, then the prefabricated model is positioned in a mold and poured with liquid metal, the liquid metal is filled in the holes of the prefabricated model, powder materials in a forming block are dissolved and removed after cooling, thereby the foamed metal of three-dimensional network through holes is obtained. The foamed aluminum gained in the invention has a three-dimensional network structure with holes communicated with one another, and the porosity and aperture can be adjusted in the range of between 80 percent and 98 percent and between 0.5 and 5mm respectively.