64 results about "Methyltrichlorosilane" patented technology

A method for manufacturing a part of SiC / SiC composite material includes the production of a fibrous preform from silicon carbide fibers; the deposition of an interphase on the fibers of the fibrous preform; a first densification including the formation of a first matrix phase by chemical vapor infiltration with a first matrix precursor including methyltrichlorosilane (MTS); a second densification including the formation of a second matrix phase by chemical vapor infiltration with a second SiC precursor different from the first precursor, the second precursor forming an SiC deposit comprising residual hydrogen and free silicon; and a third densification including the impregnation of the fibrous preform with an impregnation composition containing at least silicon so as to obtain a part made of SiC / SiC composite material.

The invention provides a preparation method of a coated particle dispersion fuel, which comprises the following steps: mixing silicon carbide powder and a binder according to a preset mass ratio, banburying and granulating to obtain a silicon carbide matrix feed; printing a silicon carbide shell green body by using powder extrusion printing equipment and the silicon carbide matrix feed; degreasing the silicon carbide shell green body by using a degreasing solvent to obtain a silicon carbide shell brown blank; a cavity of the silicon carbide shell brown blank is filled with cladding fuel particles, and pores of the cladding fuel particles are filled with silicon carbide powder; and filling the filled silicon carbide shell brown blank into a chemical vapor infiltration device, generating silicon carbide by the introduced methyl trichlorosilane, filling a gap between the silicon carbide powder and the silicon carbide shell green blank with the silicon carbide, and obtaining the coated particle dispersion fuel after the chemical vapor infiltration is completed. By adopting powder extrusion printing and chemical vapor infiltration methods, the problems that the irradiation swelling resistance of existing coated particle dispersion fuel is reduced, the heat conductivity is low, and the loading capacity of coated fuel particles is limited are solved.

The invention relates to the technical field of organic silicon resin preparation, in particular to trapezoidal methyl silicon resin and a preparation method thereof.The trapezoidal methyl silicon resin is prepared by taking methyl trichlorosilane as a main raw material, introducing a trapezoidal control agent containing amido and alkoxy at the same time to inhibit the reaction activity of the methyl trichlorosilane and then carrying out hydrolysis reaction in a small amount of alcohol solvent and water; the generation of a cross-linked network structure insoluble substance during hydrolysis is avoided, and the resin gelation risk is effectively reduced. The hydrolysis rate is reduced, so that the use amount of the solvent is reduced, the proportion of alcohol in the water phase is greatly reduced, and the process and environmental protection cost is reduced. The trapezoidal methyl silicone resin prepared by the method is excellent in viscosity performance, high in yield, excellent in boiling resistance, short in curing time, high in resin softening point and short in gelation time.

The invention relates to a preparation method of a low-resistance silicon carbide coating based on a molybdenum / tantalum metal electrode, which comprises the following steps: S1, substrate pretreatment: carrying out mechanical micro roughening, ultrasonic cleaning and drying on a Mo / Ta electrode, and then reducing to remove an oxidation film; s2, Si-rich nucleation: taking methyl trichlorosilane as a Si / C common source, hydrogen as carrier gas / reducing gas and nitrogen as an n-type doping source for gas supply to form a compact nucleation layer; s3, main body deposition is conducted, specifically, the temperature is adjusted to 1140-1180 DEG C, the total pressure is maintained to be 80-120 Torr, and gas supply continues to be conducted for deposition; s4, annealing and dechlorination: stopping methyl trichlorosilane, keeping hydrogen and nitrogen flushing, and then annealing; and S5, cooling and shaping: cooling and taking out the sample annealed in the step S4, and adjusting the surface roughness to a set value to obtain the low-resistance silicon carbide coating on the Mo / Ta electrode. Compared with the prior art, on the premise that conductivity is not sacrificed, atomic oxygen / oxygen ion resistance, sputtering resistance, thermal cycling stability and the like of the Mo / Ta electrode can be remarkably improved.

The invention discloses a device and a method for preparing a fiber-reinforced SiC ceramic-based composite material based on Joule thermochemical vapor infiltration. The device is specifically characterized in that a graphite clamp and a fiber preform are arranged in a reactor, a trichloromethylsilane container, a flowing protective gas introduction device and a tail gas treatment device are respectively communicated with the reactor through gas pipes, and the fiber preform is connected with an external power supply through fibers extending outwards; the preparation method comprises the following steps: putting a fiber fabric preform and a graphite clamp into a reactor, connecting the fiber preform into a circuit, heating the interior of the fiber preform, introducing methyltrichlorosilane and hydrogen into the reactor, turning off a power supply, and cooling a sample to room temperature, thereby completing the preparation. Local high temperature is formed through Joule heat, heating is conducted from the inside to the outside of the preform, SiC is deposited on the fiber preform from inside to outside, so that the material achieves high uniformity, internal pores are reduced, and the density and the deposition rate are improved.

The invention discloses a method for preparing methyltriacetoxysilane from acetic anhydride-containing acetyl chloride distillation tailings, and relates to the technical field of organic silicon synthesis, the method comprises the following steps: adding methyl trichlorosilane and acetic anhydride-containing acetyl chloride distillation tailings into a reaction kettle, stirring and heating; after a total reflux condition is reached, maintaining total reflux for a period of time, and then starting to collect acetyl chloride; continuously heating until the collection of acetyl chloride is completed, stopping heating, and when the temperature of the kettle is reduced to room temperature, heating again and starting vacuum negative pressure; when the kettle temperature reaches a set value, stopping heating, stopping stirring, and closing vacuum negative pressure; and after the kettle temperature is reduced to room temperature, adding pretreated activated carbon, carrying out decoloration reaction, and carrying out suction filtration after the reaction is completed, thereby obtaining the product. According to the method, a large amount of acetic anhydride in the acetyl chloride distillation tailings is used as a raw material and directly reacts with methyl trichlorosilane to prepare methyltriacetoxysilane, and the quality of the obtained product is remarkably higher than that of a product prepared by a normal process.

The invention discloses a SiC nanowire in-situ modified ceramic matrix composite connecting fastener and a preparation method thereof, and belongs to the technical field of ceramic matrix composites. The preparation method comprises the following steps: carrying out heat treatment on a fiber preform, carrying out CVD (Chemical Vapor Deposition) or CVI (Chemical Vapor Infiltration) deposition by taking boron trichloride and ammonia gas / ethylene as precursors, dipping in a catalyst solution, drying, and finally carrying out CVI deposition by taking methyltrichlorosilane as a precursor to prepare a composite material preform; the preparation method comprises the following steps: performing CVD (Chemical Vapor Deposition) or CVI (Chemical Vapor Infiltration) deposition on a composite material preform by taking silicon tetrachloride and ammonia gas as precursors, dipping in a precursor solution, drying, performing vacuum cracking treatment, and finally performing CVI deposition and thread processing by taking the silicon tetrachloride and the ammonia gas as the precursors, thereby obtaining the composite material. By means of in-situ growth of the SiC nanowires, rapid densification is achieved while strengthening and toughening are achieved, and the method has the advantages of being short in preparation period, good in product mechanical property, high in connection efficiency and the like.

The invention relates to a method and a system for improving SiC bulk doping yield based on retention boundary layer design, and relates to the technical field of semiconductor material preparation, chemical vapor deposition treatment is carried out on gas-phase raw materials on the surface of a substrate, and the gas-phase raw materials are gaseous methyl trichlorosilane, hydrogen, nitrogen and helium; the method comprises the following steps: collecting the flow rate and chemical vapor deposition processing parameters of a gas-phase raw material in real time, controlling the volume flow ratio of hydrogen to gaseous methyl trichlorosilane to be 3-15, and calculating the thickness of a retention boundary layer of the gas-phase raw material according to the flow rate and chemical vapor deposition processing parameters of the gas-phase raw material, the thickness of the retention boundary layer of the gas-phase raw material is compared with the preset thickness of the retention boundary layer, the flow velocity of the gas-phase raw material and / or chemical vapor deposition processing parameters are / is adjusted according to the comparison result, and the SiC block material prepared through the method is compact and free of pores or free carbon or silicon carbide nanowires, and the adjustable range of the resistivity is wide.

A method for producing a fiber-reinforced composite, is provided with: introducing a reinforcing fiber fabric into an atmosphere-controllable reaction furnace, the reinforcing fiber fabric including reinforcing fibers woven together and gaps having aspect ratios of 35 or larger between the reinforcing fibers; flowing into the reaction furnace a source gas including hydrogen and methyltrichlorosilane; and causing a reaction to create a coating of silicon carbide in the gaps by heating the reaction furnace to maintain the reinforcing fiber fabric at a temperature above 1000 degrees C. and below 1100 degrees C. with maintaining the reaction furnace at a pressure below an atmospheric pressure, whereby the coating binds the reinforcing fibers together.

The invention provides a preparation method of 1-chloromethyl silazane, and relates to the technical field of chemical synthesis. The method specifically comprises the following steps: (1) adding a first catalyst and chloromethyl trichlorosilane into a mixed material containing an auxiliary solvent and a reactive solvent, and reacting to obtain a first material; the reactive solvent is a C1-C6 alcohol solvent; (2) distilling to remove hydrogen chloride in the first material to obtain a second material; (3) adding a catalyst alkali and a surfactant into the second material, and then adding triethanolamine for reaction; and precipitating the reacted material through an anti-solvent to obtain the high-purity 1-chloromethyl silatrane. The 1-chloromethyl silazane can be prepared by a one-pot method, and the second-stage reaction is directly carried out without separation and purification after the first-stage reaction is completed, so that the intermediate loss is reduced, and the yield of the target product is increased. According to the whole preparation method, the technological process is greatly simplified, operability is high, industrial production is easy, and important economic value is achieved.

A method for increasing the nutritional value of forage used for animal feed includes exposing the forage to a vapor of methytrichlorosilane MTS in a heated environment, the MTS reacts with water moisture in the forage to form hydrochloric acid and then introducing a vapor of anhydrous ammonia which reacts with the hydrochloric acid to form and diffusely distribute ammonia chloride through material.

The present invention provides a method for extracting methyl tributylacetoximate silane, belonging to the technical field of oxime silane extraction. Specifically, a mixture of methyl tributylacetoximate silane and a solvent is prepared from methyl trichlorosilane, butanone oxime and 120# solvent gasoline raw materials, and the solvent and unreacted butanone oxime are evaporated by a thin film evaporator to obtain a methyl tributylacetoximate silane finished product; in addition, the present invention provides an extraction synergist, which effectively improves the extraction efficiency of a turbo extraction tower, further improves the raw material utilization rate, and reduces production losses.

The invention relates to a [BMIM] Cl (at) MCM-41 catalyst and a method for synthesizing methyl trichlorosilane, the preparation method of the catalyst comprises the following steps: a) preparing an MCM-41 mesoporous molecular sieve by adopting a hydrothermal synthesis method, the specific method for preparing the MCM-41 mesoporous molecular sieve is as follows: taking cetyltrimethylammonium bromide (CTAB) as a template agent, taking tetraethyl orthosilicate (TEOS) as a silicon source, and adopting a hydrothermal synthesis method for preparing the MCM-41 mesoporous molecular sieve; the preparation method comprises the following steps of: mixing and stirring the MCM-41 molecular sieve serving as a raw material and tetramethylammonium hydroxide (TMAOH) serving as an alkali solution to form gel, dealcoholizing, crystallizing, washing, drying and calcining to obtain the MCM-41 mesoporous molecular sieve. The [BMIM] Cl (at) MCM-41 is used as the catalyst for synthesizing methyl trichlorosilane by a Grignard reagent method, the mesoporous structure of the MCM-41 improves the diffusion efficiency of reactants, and the structure is matched with the molecular size of the ionic liquid to form a uniformly dispersed active center and shorten the contact path of the reactants.

This invention provides a denitrification catalyst suitable for alkali furnaces, its preparation method, and its application, comprising the following raw materials: TiO2 support, pore modifier, vanadium precursor, tungsten precursor, Ce-modified component, and La-modified component; based on the mass of the TiO2 support, the mass percentages of the pore modifier are 3-7%, the vanadium precursor is 1-3%, the tungsten precursor is 1-7%, the Ce-modified component is 1-5%, and the La-modified component is 0.5-1.5%; the pore modifier is methyltrichlorosilane. This invention uses a V-W-Ti system as its base. By modifying the pore structure of the TiO2 support, capillary condensation is eliminated, and hydrophobicity is achieved; Ce modification of the V-W-Ti system enhances the selective adsorption of oxygen vacancies and NH3; and La modification of the V-W-Ti system enhances the acidity of the catalyst and provides alkali metal sacrificial sites. These three components synergistically address the problems of water poisoning, alkali poisoning, and insufficient activity at low temperatures.

The application relates to a silicon carbide composite material preparation method based on optimization of a CVI deposition rate and a silicon carbide fiber reinforced silicon carbide composite material, which comprises silicon carbide fiber preform weaving, preform molding and drying, BN interface deposition, CVI densification and MI densification; the CVI densification takes methyltrichlorosilane as a precursor, hydrogen as a carrier gas and a reducing agent, the total supply flow rate of the hydrogen is controlled in the range of 9-11 L / min ‑1 , the reaction temperature is 1000-1300 DEG C, the system pressure is 20-25 kPa, and the deposition time is 50-80 hours. In the application, the hydrogen carrier gas flow rate in the CVI densification process is controlled in an optimization range, the phenomenon that the preform surface is prematurely sealed can be effectively avoided while sufficient precursor supply and higher deposition efficiency are ensured, the reaction gas can be fully penetrated into the preform and uniform deposition is realized, and the overall density and structural uniformity of the composite material are effectively improved.

Multi-stage continuous esterification reaction treatment equipment is used for producing methyltrimethoxysilane by taking methyl trichlorosilane and methanol as raw materials, and comprises a first esterification kettle, a second esterification kettle, a third esterification kettle, a neutralization reaction kettle, a centrifugal separation device and a rectification purification device which are communicated in sequence. The equipment has the advantages of simple reaction condition control, low equipment investment and maintenance cost, high flexibility and the like.

A method for increasing the nutritional value of forage used for animal feed includes exposing the forage to a vapor of methytrichlorosilane MTS in a heated environment, the MTS reacts with water moisture in the forage to form hydrochloric acid and then introducing a vapor of anhydrous ammonia which reacts with the hydrochloric acid to form and diffusely distribute ammonia chloride onto and through forage material.

The invention belongs to the technical field of chemical vapor deposition, and particularly relates to a method for synthesizing methylsilane to grow a 4H-SiC single crystal by using an ionic liquid catalyst, which comprises the following specific steps: step 1, taking high-purity methyltrichlorosilane (MeSiCl3) as an initial raw material, the preparation method comprises the following steps: reacting a raw material with an ionic liquid catalyst 1-ethyl-3-methylimidazole aluminum chloride [EMIM] [AlCl4] in a specific molar ratio to synthesize electronic-grade methylsilane, synthesizing the electronic-grade methylsilane by using the ionic liquid catalyst, and realizing high-efficiency and high-quality crystal growth by using an accurately controlled adsorption purification and crystal growth process. Particularly, the infrared thermometer is arranged in the HTCVD equipment, and the measurement accuracy of the infrared thermometer reaches + / -1 DEG C, so that the infrared thermometer plays a key role in monitoring the temperature control in the crystal growth process, and the uniformity and repeatability of crystal growth are ensured.

The invention discloses high-refraction phenyl silicone oil and a preparation method thereof, and relates to the technical field of organosilicone, the high-refraction phenyl silicone oil comprises the following raw materials: phenyl trichlorosilane, diphenyl dichlorosilane, methyl trichlorosilane, dimethyl dichlorosilane, hexamethyldisiloxane, a catalyst and a solvent; the preparation is performed based on the raw materials. According to the invention, by reasonably regulating and controlling the ratio of the phenyl trichlorosilane to the diphenyl dichlorosilane, premature crosslinking of the system is avoided while high refractive index is maintained; by introducing methyl trichlorosilane and dimethyl dichlorosilane, the flowability and viscosity are accurately adjusted, and the optical performance and the processability are both considered; and hexamethyldisiloxane is added in batches in the condensation stage to form a uniform end sealing structure, so that the high-refraction phenyl silicone oil with narrow molecular weight distribution and stable and controllable refractive index is obtained. The transparency and the thermal stability of the material are improved, and the bivariate accurate matching capability of the refractive index and the viscosity is remarkably improved.

The invention provides a method for preparing methyl chlorosilane by using methyl chlorosilane high-boiling cracking residual liquid. The method comprises the following steps: by taking methyl chlorosilane high-boiling residue cracking raffinate, methyl trichlorosilane and trimethyl chlorosilane as main raw materials and Al2O3-V2O5-WO3 as a catalyst, carrying out cracking disproportionation in a high-pressure reaction kettle under the conditions of heating and pressurizing, and rectifying and separating a reaction product to obtain the dimethyl dichlorosilane. According to the method, the high-value dimethyldichlorosilane can be prepared from the hazardous waste methyl chlorosilane high-boiling cracking residual liquid through the disproportionation reaction, so that cyclic utilization of the high-boiling residue cracking residual liquid is realized, and the problems that the high-boiling residue cracking residual liquid is large in discharge amount, difficult to treat and the like are solved; and through catalysis of Al2O3-V2O5-WO3, the selectivity of dimethyldichlorosilane can be improved, toxic aniline substances carried in high-boiling residue cracking raffinate can be adsorbed, and the problems of environmental pollution and the like are solved.

The invention discloses a device and a method for separating chlorine from gas-phase white carbon black tail gas. The device comprises a fan, a plate type washing tower, an acid absorption tower, a membrane separation device and an alkali absorption tower group, the fan is used for sequentially conveying tail gas into the devices for circulation; the plate type washing tower is used for washing white carbon black in tail gas; the acid absorption tower is used for absorbing hydrogen chloride gas in the tail gas; chlorine and carbon dioxide mixed air in the tail gas can be separated through the membrane separation device; the alkali absorption tower group can respectively absorb chlorine to form a sodium hypochlorite solution and absorb the rest of mixed air to be discharged after reaching the standard, the device and the method for separating chlorine from the gas-phase white carbon black tail gas are provided, hydrogen chloride and chlorine in the tail gas generated in production of white carbon black from methyl trichlorosilane are separated, the tail gas is discharged after reaching the standard, and the production cost is reduced. The sewage generation amount is extremely small, and the sewage treatment cost is greatly reduced.

The invention relates to a process for depositing a silicon carbide coating on the surface of a graphite piece, which is characterized by comprising the following steps: S1, placing the cleaned graphite piece in a deposition chamber, closing the chamber, and vacuumizing; s2, depositing a transition layer on the surface of the graphite piece, S3, introducing double precursor gases, hydrogen and argon into the deposition chamber, and depositing on the surface of the transition layer to obtain a silicon carbide layer; s4, stopping introducing the gas, carrying out heat preservation for a period of time, then bombarding the surface by using inert gas plasma for etching, and continuously carrying out heat preservation to obtain a product; the double precursor gas comprises methyl trichlorosilane and methylsilane. The method has the effect of improving the bonding strength of the silicon carbide coating and the surface of the graphite piece.

The invention provides a methyltrimethoxysilane tail gas treatment process capable of efficiently recycling raw materials and completely eradicating blockage. The invention creatively designs a'condensation-methanol spraying reaction-secondary condensation 'three-stage recovery and reaction system. Enabling tail gas to pass through a low-temperature condenser and a gas-liquid coalescer, and recovering most of liquid silane intermediates; a trace amount of methyl trichlorosilane in the residual gas phase is directionally converted into soluble alkoxy silane in a methanol spray tower under a specific temperature and pressure condition, and the soluble alkoxy silane returns to a reaction system; and finally, the tail gas is subjected to deep condensation and a gas-liquid coalescer to ensure that methanol and residual components are extremely recycled. According to the process, tail gas treatment, raw material recovery and by-product inhibition are combined for the first time, gas finally entering the absorption tower hardly contains salifying components, generation of solid particles and blockage of the absorption tower are avoided fundamentally, and great reduction of three-waste treatment cost and continuous and stable operation of production are realized.

The invention relates to a high-performance organic silicon packaging adhesive for a photovoltaic module, the packaging adhesive is an organic high-molecular compound taking a silicon-oxygen bond as a main chain, and a colloidal elastomer is formed after the packaging adhesive is cured; the working temperature range of the packaging adhesive is-55 DEG C to 250 DEG C, the light transmittance of the packaging adhesive in a visible light range is not lower than 92%, and after the packaging adhesive is aged for 1000 hours under the double-85 test conditions of 85 DEG C and 85% relative humidity, the light transmittance retention rate is larger than 95%; the packaging adhesive is prepared from a monomer mixture containing dimethyl dichlorosilane and methyl trichlorosilane through high-temperature reaction, hydrolysis and condensation processes under the action of a composite catalytic system of copper and various high polymer materials, and finally a network polymer with linear and cross-linked structures is formed. The core purpose of the invention is to provide a revolutionary photovoltaic packaging material which is high in light transmittance, extremely stable in chemical property, capable of greatly improving the reliability, the service life and the power generation efficiency of a component, and environment-friendly and recoverable.

The invention relates to a process for producing oxime silane from butanone oxime. According to the process, methyltrichlorosilane, butanone oxime and a solvent are fed into a kettle reactor. After the reaction is completed, the materials are cooled by a circulating cooler, a portion of the materials are returned to the kettle reactor for further reaction, and the other portion of the materials are fed into a separator. Liquid in the lower layer of the separator is fed into the upper part of an extraction tower. Liquid in the upper layer of the separator is evaporated by a thin film evaporator and then fed into the lower part of the extraction tower for recycling. Butanone oxime hydrochloride passes through the extraction tower, and a solvent phase containing methyltributylanoneoxime silane is extracted and overflows from the top of the extraction tower. The collected solvent is returned to the reactor for recycling. Butanone oxime hydrochloride comes out from the bottom of the extraction tower and enters a neutralizer. After neutralization, it is separated by an oil-water separator, and the upper layer of liquid is fed into a rectification unit to recover butanone oxime. The lower layer of liquid is fed into an evaporation and crystallization process, and the mother liquor after evaporation, crystallization and filtration is fed into the neutralizer for recycling. The oxime silane prepared by the invention has high purity and chromaticity.

The application relates to a purification process and device for CVD-SiC coating precursor methyltrichlorosilane, and the purification process comprises the following steps: filtering methyltrichlorosilane raw material by using a pre-filter to obtain filtered methyltrichlorosilane; sequentially adsorbing the filtered methyltrichlorosilane by using two adsorption columns connected in series to obtain adsorbed methyltrichlorosilane, wherein porous SiO2 microspheres are used as adsorbents; filtering the adsorbed methyltrichlorosilane by using a terminal filter to obtain high-purity methyltrichlorosilane. The process adopts a normal-temperature liquid-phase route of pre-filtering, double-column series adsorption and terminal filtering, uses porous SiO2 microspheres as adsorbents, removes B and P impurities by using the Lewis acid-base coordination of Si-OH on the surface of SiO2 and BCl3 and PCl3 under the protection of anhydrous and slightly pressurized nitrogen, controls metal impurities such as Na, Mg, Al, K, Ca, Fe, Ni and Cu through a 316L EP metal-dissolution-free system, and prevents secondary pollution.

The invention relates to a method for chemical vapour deposition of a coating on a substrate, comprising at least the following steps: - a step of placing the substrate (100, 200) in a reaction chamber; - a step of obtaining a first layer (101, 201), by supplying the chamber with a mixture of dihydrogen and methyltrichlorosilane in a first H2 / methyltrichlorosilane volume ratio, the chamber being at a first temperature and at a first pressure; and - a step of obtaining a second layer (102, 203), by supplying the chamber with a mixture of dihydrogen and methyltrichlorosilane in a second H2 / methyltrichlorosilane volume ratio that is different from the first ratio, the chamber being at a second temperature and at a second pressure, at least one of the second volume ratio, the second temperature and / or the second pressure being different from the first volume ratio, the first temperature and / or the first pressure, respectively.

The invention provides a preparation method of hydrophobic nano silicon dioxide, which comprises the following steps: introducing dimethyl dichlorosilane gas and methyl trichlorosilane gas into hydrophilic nano silicon dioxide, and reacting at 250-400 DEG C to generate the hydrophobic nano silicon dioxide. The preparation method comprises the following steps: directly introducing dimethyl dichlorosilane and methyl trichlorosilane into hydrophilic nano silicon dioxide at the temperature of 250-400 DEG C in the form of gas, and directly reacting the dimethyl dichlorosilane and the methyl trichlorosilane at high temperature to obtain the hydrophobic nano silicon dioxide. Monomethyl trichlorosilane is taken as a main hydrophobic raw material, so that the production cost can be remarkably reduced, and in order to improve the yield of hydrophobic nano silicon dioxide obtained by monomethyl trichlorosilane and hydrophilic nano silicon dioxide, dimethyldichlorosilane gas is also used, so that the yield of the hydrophobic nano silicon dioxide is improved. The two gases jointly promote the mutual reaction with the hydrophilic nano silicon dioxide, so that low-cost and high-efficiency preparation of the hydrophobic nano silicon dioxide is realized.

The present invention relates to a method for preparing chlorosilanes, the method comprising the steps of: preparing a reactant comprising methylchlorosilane synthesis residue and methyldichlorosilane (MH); and reacting the reactant in the presence of an alumina catalyst to form a product comprising dimethyldichlorosilane (M2), methyltrichlorosilane (M1), and trimethylchlorosilane (M3), wherein the reaction is carried out at 300-500°C for 1-3 minutes.

This invention discloses a hydrophobic and oleophilic aerogel environmentally friendly composite material for oil-water separation, comprising: mixing and stirring a mixture of silicon tetrachloride and magnesite powder, followed by precipitation to obtain a SiO2 / MgSiO3 nano-hybrid material; immersing a melamine sponge in a hexane solution containing monomethyltrichlorosilane, then washing the sponge with ethanol and drying it to obtain a modified porous sponge; hydrolyzing the modified porous sponge in a mixture of glacial acetic acid and ethanol, then adding the SiO2 / MgSiO3 nano-hybrid material and a 10% sodium hydroxide ethanol solution to obtain a second-modified porous sponge; and finally air-drying the second-modified porous sponge in a mixture of trimethylchlorosilane and a monohydric alcohol to obtain the hydrophobic and oleophilic aerogel environmentally friendly composite material. The raw materials used in this invention are inexpensive and readily available, allowing for large-scale industrial production and filling a gap in the market for hydrophobic and oil-absorbing sponge production.