107 results about "Silicon dioxide" patented technology

A method and system for controlling a silicon nitride etching bath provides the etching bath including phosphoric acid heated to an elevated temperature. The concentration of silicon in the phosphoric acid is controlled to maintain a desired level associated with a desired silicon nitride/silicon oxide etch selectivity. Silicon concentration is measured while the silicon remains in soluble form and prior to silica precipitation. Responsive to the measuring, fresh heated phosphoric acid is added to the etching bath when necessary to maintain the desired concentration and silicon nitride:silicon oxide etch selectivity and prevent silica precipitation. The addition of fresh heated phosphoric acid enables the etching bath to remain at a steady state temperature. Atomic absorption spectroscopy may be used to monitor the silicon concentration which may be obtained by diluting a sample of phosphoric acid with cold deionized water and measuring before silica precipitation occurs.

The invention relates to a lithium silicate-coated Ni-Co lithium aluminate positive electrode material and a preparation method thereof. The mass percent of lithium silicate in the material accounts for 1-10wt%, a coating layer with a thickness being 2-20 nanometers is formed from the silicon silicate and is coated on Ni-Co lithium aluminate, and the positive electrode material is a spherical particle with a grain size being 5-15 micrometers. The method comprises the following steps of (1) adding a silicon source into an organic solvent, performing uniform stirring, adding water, adding Co-Alnickel hydroxide, performing heating and stirring reaction, and performing drying to obtain silicon dioxide-coated Co-Al nickel hydroxide precursor powder; and (2) grinding and uniformly mixing the silicon dioxide-coated Co-Al nickel hydroxide precursor powder and a lithium salt, placing the mixture in a tubular furnace, and performing two-segment calcination under an oxidization atmosphere, thereby obtaining the lithium silicate-coated Ni-Co lithium aluminate positive electrode material. The positive electrode has relatively good cycle stability and large-rate discharging performance; and bythe method, the problem of lithium resided on a surface during conventional coating can be effectively reduced, and the method is low in cost and simple in process and is suitable for industrial production.

It is an object of the present invention to provide a tire rubber composition excellent in performances such as silica dispersibility and processability. The present invention relates to a tire rubber composition, comprising: a rubber component; silica; and a silane coupling agent, wherein the silica has a CTAB specific surface area of 180 m²/g or more and a BET specific surface area of 185 m²/g or more, and the silane coupling agent is a copolymer comprising units A represented by formula (1) and units B represented by formula (2), and the proportion of the units B is 1 to 70 mol % of the total molar amount of the units A and the units B.

Provided are a rubber composition for a tire cord topping, a breaker edge strip, a breaker cushion, or a strip adjacent to cords, which achieves a balanced improvement in handling stability, fuel economy, durability, ride quality, and adhesion; and pneumatic tires including the same. The rubber composition includes: an isoprene-based rubber; a phenol resin and/or an alkylphenol resin; and a partial condensate of HMMM and/or a partial condensate of HMMPME, wherein an amount of the isoprene-based rubber is 60% by mass or higher per 100% by mass of the rubber component; and a combined amount of the phenol resin and the alkylphenol resin is 2-3.9 parts by mass, a combined amount of the partial condensate of HMMM and the partial condensate of HMMPME is 0.5-5 parts by mass, and an amount of silica is at most 15 parts by mass, each per 100 parts by mass of the rubber component.

The invention relates to a preparation method for a super-hydrophobic/super-oleophylic loofah sponge fiber and an application thereof. The method comprises the following steps: pretreating loofah sponge fiber with sodium hydroxide and hydrogen peroxide and standing by; taking a certain amount of polyurethane adhesive and gas-phase nano-silica and adding into an acetone solvent; ultrasonically dispersing for 2-4 hours, thereby acquiring an acetone dispersion liquid; adding the pretreated loofah sponge fiber into the acetone dispersion liquid and ultrasonically dispersing for 2-10 hours; and drying in an oven, thereby acquiring the super-hydrophobic/super-oleophylic loofah sponge fiber used for effectively separating oil or organic solvent from water mixture. The preparation method provided by the invention is simple and quick; the used raw materials are economical, easily acquired and easy to degrade; the virulent fluorine-containing surfactant is not required; the prepared super-hydrophobic/super-oleophylic loofah sponge fiber has higher stability, excellent super-hydrophobic property and efficient oil water separation capacity; and besides, the prepared super-hydrophobic/super-oleophylic loofah sponge fiber has excellent strong acid resistance, strong base resistance, high salinity resistance, high temperature resistance and extensive social benefit and economic benefit.

The invention relates to the field of photocatalysis, and particularly relates to a visible-light-driven photocatalyst for degrading dye in wastewater, and preparation and application thereof. The visible-light-driven photocatalyst for degrading dye in wastewater is characterized in that mesoporous silicon dioxide of which the framework contains Ti atoms is used as a carrier, the mesoporous silicon dioxide carrier carries graphitic carbon nitride, and bivalent Cu ions are doped on the graphitic carbon nitride, wherein the graphitic carbon nitride with the doped cupric ions serves as a main catalyst, and the element Ti serves as a cocatalyst. The Ti atoms contained in the framework of the mesoporous silicon dioxide directly react with H2O2 in a photo-Fenton-like system to produce hydroxyl free radicals, thereby obviously improving the photo-Fenton-like reaction activity. The photocatalyst provided by the invention catalyzes degradation of methyl orange and/or rhodamine B in wastewater, and degradation can be performed at room temperature under the irradiation of visible light, thereby enabling the photocatalyst to have the advantages of mild reaction conditions, low cost and easy implementation; and the photocatalyst can be easily regenerated, and still has excellent photocatalytic performance after being regenerated many times.

A making method of a composite type biological chip based on a photonic crystal comprises four steps which are preparation of hard substrates, preparation of photonic crystal thin membranes, connection of membranous substrates and surface treatment of the substrates. (1) the preparation of hard substrates: common hard substrates are cleaned by soapy water, washed by de-ionized water and dried, and amino-group or hydroxyl is decorated on the surfaces of the substrates; (2) the preparation of photonic crystal: the nano-microspheres such as specific monodisperse silicon dioxide or polystyrene and the like, which are different in size according to the positions of testing signals, are assembled on the surfaces of the treated substrates to form the photonic crystal thin membrane with the thickness of 20 to 30 microns (3) the connection of membranous substrates: the surface of the photonic crystal thin membrane is laid with a layer of the membranous substrate and the connection is fixed by utilizing the chemisorption or the mutual function between positive and negative charges; (4) the surface treatment of the substrates: by using the methods such chemisorption and the like, chemical groups which can be fixedly connected with biomolecules to be tested are decorated on the membranous layer parts of the surfaces of the composite substrates which are formed in the step (3).

The invention relates to a fiber reinforced ceramic-based composite material antenna cover for a wave band W and a preparation method thereof. The fiber reinforced ceramic-based composite material antenna cover is a product prepared from a quartz fiber perform by pre-sizing with a copying-locating tool, repeated and circular soaking and drying, repeated and circular soaking after rough machining,drying thermal treatment, circular soaking of a silica solution after finish machining, and ceramic thermal treatment molding. The quart fiber enhanced silicon dioxide composite material is taken as the raw material. The antenna cover is applied to a wave band W. The antenna cover has high mechanical, thermal and electric performance and high appearance quality, is 2 to 3mm in thickness, passes awave-transmitting performance test on the wave band W, has a wave-transmitting rate of larger than 60 percent, passes static test examination, meets the application requirement of the wave band W of the antenna cover, and fills the technical blank of the technical field.

The invention discloses a method for preparing amorphous ultrafine silicon oxide by a hydrothermal method, which comprises the following steps: adding a surfactant into deionized water, heating to 60-80 DEG C, stirring to obtain a uniformly dispersed solution; slowly adding a silicon source solution into the above solution to obtain a mixed solution, continuing to stir for 5-10 min to allow the mass ratio of the surfactant and SiO2 in the silicon source solution to be 1%-9%; slowly adding sulfuric acid to adjust the pH to 8-12 so as to obtain a silicic acid gel precursor, allowing the mass concentration range of silica in a reaction system to be 1%-9%, transferring the silicic acid gel precursor into a stainless steel high-temperature high-pressure reaction vessel, stirring at 150-500 rpm, sealing the vessel and aging at 140-200 DEG C for 4 hours, after the reaction, allowing the system temperature to decrease to below 80 DEG C, filtering, washing, and drying at 120 DEG C for 2 hours. The method of the invention has low production cost, small silica particle sizes, and simple preparation process, and is easy to realize industrial production.

The invention relates to a high-temperature resistant heat insulating material using vermiculite as a main raw material and a method for manufacturing the same, which belong to the field of heat insulating materials. The method is characterized by comprising the following steps: firstly, quickly heating and swelling commercially available primary minerals of the vermiculite with large, medium and small diameters at a temperature of between 500 and 900 DEG C; secondly, mixing the swelled vermiculite with an aluminum dihydrogen phosphate bonding agent, aluminum hydroxide or rho-alumina, and nano-silica according to the requirement of weight percentage; stirring the mixture evenly in an airtight stirring machine and then filling the mixture into a die; after prepressing, performing hot pressing and shaping on the mixture; and after discharging, finishing the product properly to obtain the high-temperature resistant heat insulating material using the vermiculite as the main raw material. Through grain composition, density control, addition of the nano-silica and application of the high-temperature resistant bonding agent, and using small grained primary minerals of the vermiculite with large yield and low cost, the high-temperature resistant heat insulating material and the method solve the bottleneck problems of insufficient supply of large grained primary minerals of the vermiculite, and the improvements on the strength and the service temperature of the vermiculite heat insulating material at the same time, thus the material can keep a low coefficient of thermal conductivity under a high temperature condition.

The invention provides a ceramic floor tile with diatom mud and a method for manufacturing the ceramic floor tile. The ceramic floor tile comprises a base layer, a surface layer and an adhesion layer. The adhesion layer is arranged between the base layer and the surface layer, and the base layer is made of the diatom mud, feldspar, kaolin, quartz, clay, porcelain clay, moire stone, marble, broken iron, polystyrene and polyacrylate; the surface layer is made of the diatom mud, Kunshan stone, carborundum disc stone, colorants, pebble, glass cloth, plastic particles, polyurethane, ethylene-ethylic acid ethylene copolymers, silicon dioxide and aluminum oxide. The ceramic floor tile and the method have the advantages that the ceramic floor tile is made of nontoxic and pollution-free raw materials, and the diatom mud which is a main material is easy to obtain, is natural and pollution-free and has diversified sterilization, disinfection and waterproof merits; the ceramic floor tile is made of the easily available materials, processing and manufacturing processes are simple, and the ceramic floor tile manufactured by the aid of the method is high in smoothness and quality.

The invention belongs to the field of optical thin film materials and particularly relates to a method for preparing a high-hardness antireflection film on the basis of hollow silicon dioxide. The method takes tetraethoxysilane as the raw material, polyacrylic acid as a templating agent, 2-isopropoxy ethyl alcohol and methyl alcohol as solvents together, and ammonium hydroxide as a catalyst to prepare a hollow SiO2 coating film sol through a template method, and a two-sided thin film is plated on a glass substrate through a dip-coating method. After being calcined at 550 DEG C, the antireflection film is obtained, the average light transmittance is more than 98% within the light transmittance wavelength range of 400-800 nm, and the hardness is more than 4H.

The present invention relates to a novel nickel catalyst. The present invention also relates to a process for the preparation of an improved nickel catalyst. The present invention also relates to a process for hydrogenation of m-dinitro benzene to m-phenylene diamine using the said improved catalyst. More particularly the present invention relates to a process involving hydrogenation of m-dinitrobenzene to m phenylene diamine in the presence of a supported bimetallic platinum catalyst, using methanol as a solvent. The catalyst system consisting of one metal selected from platinum group and other nickel supported on either carbon or alumina or silica or zeolite. The catalyst of the present invention is a bimetallic catalyst prepared by precipitation and impregnation technique at very specific preparation conditions.

The invention discloses a preparing method of a high-breathability and super-hydrophobic polyether sulfone hollow fiber membrane. The preparing method includes the steps of (1) preparing a high-breathability polyether sulfone hollow fiber membrane; (2) preparing a fluoridized silicon dioxide sol-gel filtering liquid; (3) preparing the hydrophobic polyether sulfone hollow fiber membrane. A specific inner coagulating bath is selected through a dry-wet method to prepare the single-skin high-breathability PES hollow fiber membrane, then silicon dioxide sol-gel is prepared through a sol-gel method, fluorine-containing silicane is used for modifying the silicon dioxide sol-gel to prepare the fluoridized silicon dioxide sol-gel filtering liquid, and the fluoridized silicon dioxide sol-gel filtering liquid is deposited to one side of the high-breathability PES hollow fiber membrane through a vacuum filtration method to prepare the polyether sulfone membrane with the single side having super hydrophobicity. The method is simple in process and easy to operate, extra equipment does not need to be arranged additionally, and hydrophobicity of the specific membrane side can be improved just through few substances low in surface energy.

The invention discloses high infrared shielding rate thermal insulation paint. The paint is prepared from substrate paint, SiO2 aerogel, hollow glass beads with an indium and antimony co-doped type tin oxide coating, surfactant, a curing agent and auxiliaries; in the tin oxide coating, the doping ratio of indium ranges from 0.5 mol% to 3 mol%, and the doping ratio of antimony ranges from 6 mol% to10 mol%; the particle size of the hollow microspheres ranges from 1,000 meshes to 2,000 meshes; the surfactant is anion and amphoteric mixed surfactant; the auxiliaries comprise a dispersing agent, awetting agent, a defoaming agent and a flatting agent. The paint has an infrared light shielding barrier forming a large specific surface area, and can effectively insulate heat and absorb and shieldthe infrared light within a wide wavelength range. The paint prepared through a method has the good homogeneity, the SiO2 aerogel can be uniformly dispersed in the paint system, and then the obtainedcoating has the uniform and stable heat insulation and infrared light shielding performance.

A coating composition for forming a glossy, inkjet-receptive coating on a substrate includes (a) a cationic polymer, and (b) colloidal silica having an average particle size in the nanometer range.

The invention provides a preparation method for polyvinyl alcohol/silicon dioxide composite microspheres and belongs to a preparation method for a composite microsphere material. Polyvinyl alcohol and tetraethyl orthosilicate are employed as raw materials, and polyvinyl alcohol/silicon dioxide (PVA/SiO2) composite microspheres are prepared in a water-in-oil system without any surfactants. Tetraethyl orthosilicate is hydrolyzed fully in a PVA solution in an acidic condition, and uniform PVA/SiO2 composite sol is formed; the sol is subjected to dispersion and crosslinking in a water-in-oil system without surfactants, and finally PVA/SiO2 composite microspheres are obtained. The technology is simple, the repeatability is good, energy consumption is low and the cost is low. Surfactant residual and agglomeration of nano inorganic particles in the process of preparing composite microspheres through a traditional emulsification method are avoided. The microspheres are advantaged by regular sphere, high dispersibility and uniform microstructure, and can be used as a drug carrier, an injection-type bone tissue repairing material or a heavy metal ion adsorption material.

The invention discloses a stone surface polishing coating agent, and preparation method and application thereof. The stone surface polishing coating agent is characterized by comprising the following constituents in percentage by weight: 30-40% of nano-scale silicon dioxide, 5-8% of acrylic resin, 5-8% of epoxy resin, 8-12% of AEO (Primary Alcobol Ethoxylate) emulsion, 0.1-0.2% of coupling agent 560#, 1-2% of hydroxyl silicone oil and 25-50% of water. The stone surface polishing coating agent can be used on surface of natural stone and artificial quartz stone to keep the stone surface fresh and bright longer, and the antifouling effect is stronger.

The present invention discloses a method for preparing a silica sol modified azodicarbonamide foaming agent, and belongs to the field of preparation of foaming agents. According to the method, methyltrimethoxysilane and sodium dodecyl benzene sulfonate are mixed for preparation of a modified silane solution, then ammonia water is dropwise added into the modified silane solution for preparation of silica hydrosol, by mutual dispersion of the silica hydrosol and azodicarbonamide, the azodicarbonamide is fully mixed by silica, and the purposes of not easy agglomeration and moisture absorption of the prepared foaming agent can be achieved. The beneficial effects are that: the preparation method is simple, after the prepared product is mixed with a liquid or a paste-like polymer, the product is not easy to agglomerate; when the foaming agent is used in foaming, particles are dispersed uniformly, the product surface is smooth and free of pocking marks, and the use effect is good.